Search

3D-printing technology allows scientist to fabricate easily electrochemical sensors. Until now, these sensors were designed employing a large amount of material, which increases the cost and decreases manufacturing throughput. In this work, a low-cost 3D-printed on-drop electrochemical sensor (3D-PES) was fully manufactured by fused filament fabrication, minimizing the number of printing layers. Carbon black/polylactic acid filament was employed, and the design and several printing parameters were optimized to yield the maximum electroanalytical performance using the minimal amount of material. Print speed and extrusion width showed a critical influence on the electroanalytical performance of 3D-PES. Under optimized conditions, the fabrication procedure offered excellent reproducibility (RSD 1.3% in working electrode diameter), speed (< 3 min/unit), and costs (< 0.01 $ in material cost). The 3D-PES was successfully applied to the determination of phloridzin in apple juice. The analytical performance of 3D-PES was compared with an equivalent commercial on-drop screen-printed electrode, yielding similar precision and accuracy but lower sensitivity. However, 3D-PES provides interesting features such as recyclability, biodegradability, low-cost, and the possibility of being manufactured near the point of need, some of which meets several demands of Green Chemistry. This cost-effective printing approach is a green and promising alternative for manufacturing disposable and portable electroanalytical devices, opening new possibilities not only in on-site food analysis but also in point-of-care testing., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

In multiresidue analysis, the QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) is one of the most popular techniques routinely used by researchers during pesticide analysis of food and vegetable samples. Originally, the QuEChERS method was developed for analysis of pesticide residues from fruits and vegetables, but rapidly gained popularity in the extraction of analytes from different matrices. This analytical approach shows several advantages over traditional extraction techniques: it requires lower sample and solvent amounts while shortening the time of sample preparation. However, it presents some limitations for complex matrices such as those containing high amounts of chlorophyll. To overcome the problem of strong matrix effect and influence of interferences, different approaches are applied. Most are concerning modifications of the cleanup step, that is, sorbent type and its amount. Optimization of other parameters, such as sample size, hydration level, extraction solvent, and buffering, also has an impact on overall performance. Combining proper sample preparation with modern highly sensitive and selective detection techniques enables receiving desired limits of quantification. This article presents an overview of strategies employed by researchers for analysis of green, high chlorophyll content commodities and results obtained in their studies., (© 2021 Wiley-VCH GmbH.)

Ultrasonic-enhanced surface-active bismuth trisulfide based core-shell nanomaterials were developed and used as an efficient modified electrode material to construct a highly sensitive antibiotic sensor. The core-shell Bi 2 S 3 @GCN electrode material was directly synthesized by in-situ growth of GCN on Bi 2 S 3 to form core-shell like nanostar (Ti-horn, 30 kHz, and 70 W/cm 2 ). The electrocatalyst of Bi 2 S 3 @GCN nanocomposites was efficaciously broadened towards electrochemical applications. As synthesized Bi 2 S 3 @GCN promoted the catalytic ability and electrons of GCN to transfer to Bi 2 S 3 . The single-crystalline GCN layers were uniformly grown on the surface of the Bi 2 S 3 nanostars. Under the optimal conditions of electrochemical analysis, the CPL sensor exhibited responses directly proportional to concentrations (toxic chemical) over a range of 0.02-374.4 μM, with a nanomolar detection limit of 1.2 nM (signal-to-noise ratio S/N = 3). In addition, the modified sensor has exhibited outstanding selectivity under high concentrations of interfering chemicals and biomolecules. The satisfactory CPL recoveries in milk product illustrated the credible real-time application of the proposed Bi 2 S 3 @GCN sensors for real samples, indicating promising potential in food safety department and control. Additionally, the proposed electrochemical antibiotic sensor exhibited outstanding performance of anti-interfering ability, high stability and reproducibility., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Studies about the phenolic composition of yellow (Brassica alba), brown (Brassica juncea), and black (Brassica nigra) mustard seeds are still scarce in the literature. Hence, this study describes, for the first time, the use of the QuEChERS extraction method followed by UHPLC-MS/MS analysis for phenolic compound determination in the seeds of these mustard species. Under the optimized extraction and analysis conditions, twenty-one phenolic compounds were evaluated. Six, eleven, and seven were found in B. alba, B. juncea, and B. nigra seeds, respectively. The most abundant phenolic compound was sinapic acid, which was found in amounts ranging from 44 to 82 times higher than the other major compounds found in the mustard seeds, ferulic, 4-hydroxybenzoic and protocatechuic acids. Overall, these results are an important contribution to the characterization of the phenolic composition of the three in natura mustard seeds species, and support future reliable phenolic compounds determination with the QuEChERS method., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

An extraction procedure was developed for the determination of aflatoxin M 1 in milk and dairy products. A sorbent based on UVM-7 mesoporous silica was used as solid phase for the sample clean-up, and the analyte determination was carried out by HPLC coupled to a fluorescence detector. The material architecture was characterized by transmission electronic microscopy, X-ray diffraction, 29 Si NMR and nitrogen adsorption-desorption. After the optimization of extraction parameters, the influence of the matrix has been evaluated, obtaining recoveries in the range 78-105% for whole and skimmed milk and yogurt matrix. The reusability of the material was also proved. The sensitivity of the method was also evaluated, and a LOQ (0.015 μg kg -1 ) below the European legislation limit was obtained. The procedure was successfully applied for the determination of aflatoxin M 1 in real samples. The results were compared with those obtained with a reference method, being the results statistically comparable., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Chia ( Salvia hispanica ) and quinoa ( Chenopodium quinoa ) seeds are often referred to as a "superfood" or functional food as a result of the claims of numerous health benefits. This often resulted in a sudden increase in demand, which frequently exceeds existing supply capacities, fostering fraudulent practices, such as mislabeling and use of other species of inferior quality. To assess the authenticity of food products containing chia and quinoa, we developed real-time polymerase chain reaction systems for the detection of seeds of these plant species. The developed methodology using chia- and quinoa-specific primer-probe sets based on TaqMan technology was validated, and specificity, cross-reactivity, limit of detection, efficiency, and robustness were determined. The methods were successfully applied to 12 (chia) and 7 (quinoa) commercial samples, proving its suitability for the verification of the authenticity of chia- and quinoa-containing products in commercial trade.

In view of the high polarity and ubiquitous occurrence of perchlorate, achieving an ultra-trace analysis has become a challenging task. The present study aimed to develop a simple and generic pretreatment protocol based on cold-induced liquid-liquid extraction to efficiently extract perchlorate from tea and dairy products and remarkably decrease potential matrix interferences and laborious cleanup. By optimizing the pretreatment conditions, the enrichment factor of perchlorate increased by 7.79 times under the compromise between the matrix effect and extraction recovery. The validated method presented satisfactory selectivity, linearity, accuracy, precision, and matrix effect, providing recoveries of 78.2%-106.2% with RSD r ranging from 1.2% to 7.9% and RSD R less than 10.7% for tea and dairy products. This pretreatment protocol depended only on shaking, freezing, and centrifugation in one step, without additional equipment or tedious operations, which will be explored to a greater extent in complex biological or food matrices., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Salmonella spp. are zoonotic pathogens of substantial public health concern. To enable detection in the field or under instrument-free conditions, we developed a rapid and robust lateral flow fluorescent immunoassay based on strand exchange amplification (SEA-LFIA) for the quantitative detection of Salmonella spp. As far as we know, this work is the first report regarding the use of Bst DNA polymerase-assisted SEA for fluorescence sensing to detect Salmonella spp. The SEA method was further confirmed by enzymatic digestion and Sanger dideoxy sequencing. The specificity of SEA-LFIA assay was verified by 89 Salmonella strains (18 Salmonella reference strains and 71 clinical isolates) and 15 non-Salmonella reference strains (different genera). The sensitivity of SEA-LFIA assay was 6 × 10 0 CFU mL -1 of Salmonella pure culture or 3 × 10 4 CFU 25 g -1 of artificially spiked raw chicken meat. Using this assay, it was found that 37 (16%) of the 236 samples collected were positive, which was consistent with the results of conventional PCR. The cutoff value is 15 and SEA-LFIA assay only takes ∼30 min without high equipment and reagent cost. In addition, the proposed strategy can be easily extended by redesigning the corresponding amplification primers to detect target analytes. In conclusion, the optimized SEA-LFIA assay is an efficient and specific method for the detection of Salmonella spp., and can potentially serve as a new on-site diagnostic tool in life sciences.

Simple, effective, and rapid detection of chemically relevant hazards is a highly desirable research goal, which can provide early-warning information to improve the patient-care outcomes for public health. Here, we introduce a microdroplet-captured tape toward rapid SERS screening of food contaminants. The dominant sensing unit lies on functionalized microwell in conductive carbon tapes, which is simply prepared by physical punching, magnetron sputtering and electrochemical deposition of Au nanodendrites. The tape-based sensors not only possess highly branched Au nanodendrites in microwell for promoting SERS activity, but also enable anchoring the microdroplets via direct dip-pulling from pristine analytes solutions upon sticky incorporated on a glove. Early-warning SERS detection of food contaminants including Sudan-1, thiram, and thiabendazole from the real samples can be achieved by such simple sampling method. These tape-based sensors with a facile operation module and accessible signal read-out represent an innovative point-of-care testing (POCT) device for forensic, military, consumer protection, environmental monitoring, and food safety applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

A rapid method for detecting fatty acids (FAs) using terahertz time-domain spectroscopy (THz-TDS) technology combined with a metamaterial-based THz sensor was developed. We measured the THz responses to oleic acid, linoleic acid and α-linoleic acid with different numbers of double-bond, α-linoleic acid and γ-linoleic acid with different conformations. In addition, in order to explore the reason for the observed redshifts of the resonance frequencies of the four FAs, the dielectric constants of the FAs were measured in the THz region. Furthermore, the four fatty acids were also attempted to be identified by Raman spectroscopy, which was difficult to accomplish unambiguously because of the effect of fluorescence. This result thus demonstrates the power and usefulness of metamaterial-assisted THz-TDS in the rapid determination of the FAs, and its potential as a versatile tool for investigation of biological metabolism, and for food product quality, safety inspection and control., Competing Interests: Declaration of competing interest There are no conflicts to declare., (Copyright © 2019. Published by Elsevier B.V.)

Ascorbic Acid (AA) is a natural and powerful water-soluble antioxidant associated with long-lasting food products. As time passes, the AA content in products sharply decreases, and they become increasingly degraded. There are several techniques to precisely quantify AA concentrations. However, most of them employ costly laboratory instruments, such as High-Performance Liquid Chromatography (HPLC) or complex electrochemical methods, which make unfeasible recurrent AA measurements along the entire supply chain. To address this issue, we contribute with an in-field and real-time voltammetric method, carried out with a low-cost, easy-to-use, and portable device. An unmodified Screen-Printed Electrode (SPE) is used together with the device to achieve short reading times. Our method has been extensively tested in two multifruit juices using three different SPEs. Calibration curves and Limit of Detection were derived for each SPE. Furthermore, periodic experiments were conducted to study the shelf life of juices under consideration. During the analysis, a set of assays for each SPE were implemented to determine the remaining AA amount per juice and compare it with that obtained using HPLC under the same conditions. Results revealed that our cost-effective device is fully comparable to the HPLC equipment, as long as the juice does not include certain interferents; a scenario also contemplated in this article., Competing Interests: The authors declare no conflict of interest.

Mycotoxin contamination causes over $5 billion of economic loss per year in the North American food and feed industry. A rapid, low-cost, portable, and reliable method for on-site detection of deoxynivalenol (DON), a representative mycotoxin predominantly occurring in grains, would be helpful to control mycotoxin contamination. In this study, a paper-based microfluidic chip capable of measuring DON (DON-Chip) in food, feed, and feed ingredients was developed. The DON-Chip incorporated a colorimetric competitive immunoassay into a paper microfluidic device and used gold nanoparticles as a signal indicator. Furthermore, a novel ratiometric analysis method was proposed to improve detection resolvability. Detection of DON in the aqueous extracts from solid food, feed, or feed ingredients was successfully validated with a detection range of 0.01-20 ppm (using dilution factors from 10 to 10 4 ). Compared with conventional methods, the DON-Chip method could greatly reduce the cost and time of mycotoxin detection in the food and feed industry.

A novel, rapid and convenient competitive immunoassay for ultrasensitive detection of chloramphenicol residues in shrimp and honey was established combined with flow injection chemiluminescence. The carboxylic resin beads were used as solid phase carriers to load with more coating antigen due to their larger specific surface area and good biocompatibility. The surface of the silica dioxide nanoparticles was modified with aldehyde group to combine with more horseradish peroxidase and the chloramphenicol antibody. There was a competitive process between the chloramphenicol in solution and the immobilized coating antigen to combine with the limited binding site of antibody to form the immunocomplex. Silica dioxide nanoparticles played an important role in enhancing chemiluminescence signal, because the horseradish peroxidase on SiO 2 effectively catalyzed the system of luminol-PIP-H 2 O 2 . Under optimal conditions, the chemiluminescence intensity decreased linearly with the logarithm of the chloramphenicol concentration in the range of 0.0001 to 100 ng mL -1 and the detection limit (3σ) was 0.033 pg mL -1 . This immunosensor demonstrated acceptable stability, high specificity and reproducibility. The horseradish peroxidase-silica dioxide nanoparticle-chloramphenicol antibody complex successfully prepared in this article was firstly applied to the detection of chloramphenicol, and had extremely important meanings for the application of nanoparticles and enzymatic catalysis in the field of chemiluminescence., (Copyright © 2019. Published by Elsevier B.V.)

Mid-infrared analysis of reconstituted milk is proposed as a feasible solution for the detection of milk powder adulteration regardless of the blending practice. To challenge the concept, skim milk powders were spiked with three of the most reactive/unstable of potential milk adulterants: semicarbazide hydrochloride, ammonium sulfate and cornstarch. To create the wet-blended set, a fraction of each sample was reconstituted and re-spray dried at laboratory scale with a benchtop spray dryer. Dry and wet-blended adulterated samples were reconstituted prior to mid-infrared measurement and projected onto a one-class classifier SIMCA model for reconstituted skim milk. Quantitative sensitivities, determined from the normalized orthogonal distances, were compared. Although the non-industrial spray drying introduced a spectroscopic bias, as revealed by the control samples, the non-targeted mid-infrared model showed comparable sensitivities for both blending practices once the main bias-rich spectral regions were removed, validating thereby the proposed concept., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Nitrite ions (NO 2 - ) have been widely used in the food and drink industry as preservatives. However, the NO 2 - discharged into the environment is harmful to the ecosystem and human health. Due to its potential toxicity, selective and sensitive detection of nitrite is important. In this work, a rose-like Au nanoparticles/MoS 2 nanoflower/graphene (AuNPs/MoS 2 /GN) composite was fabricated using a one-pot hydrothermal method without the addition of any extra reductant for use in nitrite detection. Graphene acts as an efficient matrix for the growth of MoS 2 nanoflower (NF), and the edges of the MoS 2 NF subsequently load AuNPs. The obtained AuNPs/MoS 2 /GN composite exhibits excellent electrooxidative activity toward nitrite ions, which is attributable to its large specific surface area, good conductivity, and the synergistic catalysis of each component. Accordingly, we propose a rapid, sensitive, and cost-effective electrochemical method for nitrite detection, which achieved a linear dynamic range of 5.0 μM to 5.0 mM with a detection limit of 1.0 μM. The present work provides not only a general one-pot synthesis method for a variety of noble-transition metal dichalcogenides nanohybrids, but also an example of the fabrication of an electrochemical nitrite sensor using a nanohybrid as an enhanced material, an approach that can easily be extended to other sensors., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The adulteration of meat products by the undeclared addition of commercially available blood plasma powder is quite conceivable due to low costs, high protein contents (about 70%), and advantageous functional properties. This applies particularly to pork, which has the highest meat production rate in the European Union. Evidence of this type of food fraud has been rather difficult to identify due to the lack of appropriate analytical methods, especially when adding plasma to meat of the same animal species. Consequently, a rapid UHPLC-MS/MS method for the detection of porcine blood plasma in emulsion-type pork sausages was developed. After protein extraction and tryptic digestion in a quick and simple one-pot process, species-specific marker peptides for porcine blood cell proteins (four markers) and plasma proteins (12 markers) were measured by UHPLC-MS/MS. Emulsion-type pork sausages were produced from a variety of raw materials that differed in the age or sex of the slaughtered pigs. Sausages were spiked with 0.5, 1, 1.5, 2, 3, or 5% meat substitution by one of two plasma powders, or produced as corresponding blank samples, and subjected to different thermal treatments as full or semi-preserves. Four plasma peptides were identified for the overall sample that allowed detection down to 0.7% meat substitution from the sum of their peak areas, with 5% error probability for both false positives and negatives.

Incorporation of new readout methods with established analytical devices allows methodological innovations in analytical sciences. Herein, we present a new sensing platform by combining an ultrasensitive element analyzer, namely the laser-induced breakdown spectroscopy (LIBS) and a lateral flow strip (LFS). Ag x Au y bimetallic nanoparticles (Ag x Au y BNPs) are selected as the labels to deliver the optimal quantitative performance by analyzing the Ag (I) signal from the test (T) line of LFS. For prototypical application in pathogen detection, the LIBS-LFS sensor can achieve a detection limit of 1.6 cfu mL -1 of Staphylococcus aureus (S. aureus) within 10 min, which is superior to conventional methods. Importantly, the signals of Ag x Au y BNPs for visual and LIBS analysis are stable and still readable after the detection is finished and the test strip is stored for up to 13 days, suggesting a potential for long-term data preservation. This combination of LIBS with LFS provides a new concept toward integrated nano/analytical devices that can benefit various application scenarios., (Copyright © 2019 Elsevier B.V. All rights reserved.)

We focused on the development of a hand-held pathogen-detection device using smartphone-embedded electronic elements combined with functionalized magnetic particles (MPs) and sepharose. To perform affinity chromatography for evaluating DNA amplicons, avidin-conjugated MPs and succinimide-linked sepharose were used with biotin-primers. To mimic the centrifugal-based affinity ligand chromatography, a smartphone-mountable low-power fan was plugged into the charging port of a smartphone. The charging port stably emitted electric current at 3.0 V, and the fan blades were modified for use as a portable rotor. Based on the binding variation of MPs with DNA amplicons, the position of MPs in sepharose changed significantly during centrifugation. The change in distance was optically analyzed using the illumination sensor of the smartphone with respect to the altered transmittance due to the MPs. Amplified genes from Escherichia. coli O157:H7 samples ranging from 1.0 × 10 1 to 1.0 × 10 6  colony-forming units could be rapidly and immediately detected by the naked eye using a simple smartphone-based optical device. The results indicated that this novel biosensing technique is suitable for use as a point-of-care testing device in both industrial and clinical fields., (Copyright © 2019. Published by Elsevier B.V.)

Monitoring of food quality, in particular, milk quality, is critical in order to maintain food safety and human health. To guarantee quality and safety of milk products and at the same time deliver those as soon as possible, rapid analysis methods as well as sensitive, reliable, cost-effective, easy-to-use devices and systems for process control and milk spoilage detection are needed. In this paper, we review different rapid methods, sensors and commercial systems for milk spoilage and microorganism detection. The main focus lies on chemical sensors and biosensors for detection/monitoring of the well-known indicators associated with bacterial growth and milk spoilage such as changes in pH value, conductivity/impedance, adenosine triphosphate level, concentration of dissolved oxygen and produced CO 2 . These sensors offer several advantages, like high sensitivity, fast response time, minimal sample preparation, miniaturization and ability for real-time monitoring of milk spoilage. In addition, electronic-nose- and electronic-tongue systems for the detection of characteristic volatile and non-volatile compounds related to microbial growth and milk spoilage are described. Finally, wireless sensors and color indicators for intelligent packaging are discussed., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In this work, we propose a method that employed a smartphone to capture images obtained from a colorimetric spot test to determine ascorbic acid (AA) in Brazilian Amazon native and exotic fruits. The spot test reaction was based on reduction of Fe(III) by AA and further complexation with 1,10-phenanthroline. After optimization, the limit of detection was 8.5 × 10 -7  mol L -1 . Brazilian Amazon native fruits such as bacuri, cupuaçu, muruci, yellow mombin, as well as others as cashew, mango, orange and passion fruit, were analyzed. In order to determine the accuracy of this method, iodometric titration was used; results were in close agreement with a confidence level of 95% (paired t-test). Moreover, recoveries ranged from 87.1 to 116%. The method is economic, environmentally friendly, and portable, and might useful for small producers and family agriculture businesses unable to afford specialized laboratory analysis in the north region of Brazilian Amazon., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Foodborne illnesses are a major contributor to misery and health challenges in both rich and poor nations. Illnesses from pathogens such as Escherichia coli and Cryptosporidium parvum oocysts account for most of the cases of diarrhea in the world. Many standard methods exist for detecting these pathogens in water. However, these standard methods do not readily translate to the detection of the same pathogens in food. Detection techniques for pathogens in food are often inadequate, due to their inability to completely separate pathogens from food matrices. In this paper, we present a technique to separate and detect both Escherichia coli cells and Cryptosporidium parvum oocysts that have been embedded in ground meat. We achieve this objective by combining enzymatic digestion of the meat, hydrodynamic cavitation to disassemble pathogens from the meat, immunomagnetic separation to purify meat samples and indirect electrochemical detection of the target pathogens. Our use of hydrodynamic cavitation to separate pathogens is compared against an industry standard separation technique. Results indicate that the use of hydrodynamic cavitation amplifies the detection capabilities of our sensing technique and is overall comparable to or better than conventional stomacher sample preparation., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In this work, we present a multiplexed (eight simultaneous measurements) paper-based electrochemical device developed in a very simple way and using low-cost materials, such as paper, carbon ink and multifunctional connector headers. Meanwhile, we have also combined the paper-based electrochemical platform with a glass-fiber strip in order to integrate easily a sampling step. Both approaches, simultaneous measuring and sampling, have been applied to the determination of glucose using bienzymatic biosensors. They are fabricated by adsorbing the mixture of enzymes (glucose oxidase and horseradish peroxidase), as well as the ferrocyanide, mediator of the electron transfer, on the paper-based electrode. After drying, the measuring solution (containing either glucose standards or samples) is added and the eight corresponding chronoamperograms are recorded. In the case of the microfluidic approach for sampling purposes, the glass-fiber pad (sampler) is immersed in a container with the solution, which flows by capillarity until it reaches the working electrode. The integration of one more step of the analytical process advances towards real and useful lab-on-a-chip devices. With these designs, a linear range comprised between 0.5 and 15 mM was achieved for glucose determination, with an excellent precision. If the sampler is employed, it is not necessary to use micropipettes and, nevertheless, precise measurements are obtained. The RSD of the slopes obtained for different calibrations performed in different days, with different arrays of electrochemical cells and different solutions is ca. 1%. Accurate results are obtained in the determination of glucose in real samples (orange fruit and cola beverages)., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The use of Sudan black B as coloring agent in foods is forbidden for its toxicology effect on human organs. This work proposes an efficient and sensitive method for food security inspection targeting Sudan black B. Surface-enhanced Raman spectroscopy (SERS) is applied to the analysis of trace Sudan black B. It could be detected at concentrations as low as 0.05 mg/L in standard solutions and 0.1 mg/kg in black rice extracts with the SERS method for measurement. The linear relationship between the intensity and concentration could be used for the quantitative detection of Sudan black B. The relation between dyeing time of black rice stained by Sudan black B solution and SERS intensity was studied which indirectly showed the effectiveness of the extraction method we designed. The results of the quantitative analysis reveal the practicability of using this method to detect Sudan black B in black rice. As a rapid and sensitive detection method, SERS can be extended to detect other food products and has a great application prospect in food safety inspection., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The greatest challenge for European drug policies is how to effectively respond to the dynamic and constantly changing market for new psychoactive substances (NPS). Even small modifications in the chemical structure of substances often allow circumventing existing laws. Also in prison, the consumption of NPS is rising and there is growing evidence that NPS are responsible for a large share of drug-related problems. Ion mobility spectrometry (IMS) is the technique of choice for trace analysis of illicit drugs or explosives at security points, for example airports. Currently, databases of the reduced mobility (K 0 ) values are limited to classical drugs and should be completed with data of emerging NPS. In this article, K 0 values, LODs (0.7-3.6 ng) and drift times of 25 synthetic cannabinoids were evaluated. The data were added to existing databases of IMS which were then applied for fast screening in prison. The detection capability of the portable IMS technique was evaluated by the determination of intra-day (0.089%) and inter-day precision (0.004% to 0.14%), systematic error (0.19%), and separation capability for structurally related NPS. The applicability of the methodology was demonstrated by the successful analysis of 12 different pieces of paper impregnated with synthetic cannabinoids, 7 different cosmetics, and 5 food samples (liquids), spiked with a mixture of narcotic drugs and a synthetic cannabinoid. In addition, 14 herbal mixtures and 36 different casework samples from prisons were analyzed provided by the State Office of Criminal Investigation Rhineland-Palatinate (Germany)., (© 2019 John Wiley & Sons, Ltd.)

An impedance based microfluidic biosensor for simultaneous and rapid detection of Salmonella serotypes B and D in ready-to-eat (RTE) Turkey matrix has been presented. Detection of Salmonella at a concentration as low as 300 cells/ml with a total detection time of 1 hour has been achieved. The sensor has two sensing regions, with each formed from one interdigitated electrode array (IDE array) consisting of 50 finger pairs. First, Salmonella antibody type B and D were prepared and delivered to the sensor to functionalize each sensing region without causing any cross contamination. Then the RTE Turkey samples spiked with Salmonella types B and D were introduced into the biosensor via the antigen inlet. The response signal resulted from the binding between Salmonella and its specific antibody demonstrated the sensor's ability to detect a single type of pathogen, and multiple pathogens simultaneously. In addition, the biosensor's selectivity was tested using non-specific binding of E. coli O157 and E. coli DH5 Alpha while the IDE array was coated with the Salmonella antibody. The results also showed the sensor is capable to differentiate low concentration of live Salmonella cells from high concentration of dead Salmonella cells, and high concentration of E. coli cells. A detailed study on antibody immobilization that includes antibody concentration, antibody coating time (0.5-3 hours) and use of cross-linker has been performed. The study showed that Salmonella antibody to Salmonella antigen is not a factor of antibody concentration after electrodes were saturated with antibody, while the optimal coating time was found to be 1.5 hours, and the use of cross-linker has improved the signal response by 45-60%., Competing Interests: The authors have declared that no competing interests exist.

Foodborne salmonellosis remains a major economic burden worldwide and particularly for food industries. The diverse and complexity of food matrices pose great challenges for rapid and ultra-sensitive detection of Salmonella in food samples. In this study, combination of pathogen pre-concentration with rapid molecular identification is presented to overcome these challenges. This combination enabled effective real-time PCR detection of low levels of Salmonella enterica serovar Typhimurium without culture enrichment. Anti-salmonella antibody, immobilized on protein AG-magnetic beads, could efficiently concentrate Salmonella Typhimurium with a capturing efficiency of 95%. In the direct PCR, a strong linear relationship between bacteria concentration and the number of cycles was observed with a relative PCR efficiency of ∼92% resulting in a limit of detection (LoD) of ∼2 CFU/mL. Analysis of spiked food samples that include vegetable salad, egg yolk, egg white, whole egg and minced pork meat has validated the precision of the method. A relative accuracy of 98.3% with a sensitivity of 91.6% and specificity of 100% was achieved in the Salmonella spiked food samples. The use of a Phusion hot start DNA polymerase with a high tolerance to possible PCR inhibitors allowed the integration of direct PCR, and thereby reducing the duration of analysis to less than 3 h. The Cohen's kappa index showed excellent agreement (0.88) signifying the capability of this method to overcome the food matrix effects in rapid and ultra-sensitive detection of Salmonella in food. This approach may lay a future platform for the integration into a Lab-on-a-chip system for online monitoring of foodborne pathogens., (Copyright © 2018 Elsevier B.V. All rights reserved.)

4(5)-Methylimidazole (4(5)-MI) is a potential carcinogen with low molecule weight, highly polarity, and weak basicity. The traditional way to extract and clean-up 4(5)-MI in soy sauce using solid phase extraction is tedious and time consuming. Here we proposed a method for the determination of 4(5)-MI in soy sauce by combining a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction with liquid chromatography-mass spectrometry analysis. The impacts of solution pH, water addition, and cleanup procedure on 4(5)-MI extraction efficiency were studied. An optimized sample preparation approach involved a single step liquid-liquid extraction between acetonitrile and soy sauce under alkaline conditions, followed by primary and secondary amine clean-up. The analytical method was validated with soy sauce at three spiking levels (10, 50, 500 ng/g). The method recovery (96.2-107%) and intra-day/inter-day precision (4.1-8.4%/6.9-11.7%) were satisfactory. The method quantification limit was 10 ng/g. The developed method was successfully applied for the determination of 4(5)-MI in fourteen commercial soy sauces from local markets. The results obtained in this work suggests that the method is suitable for the analysis of 4(5)-MI at low concentrations in high-salting and protein-containing soy sauce matrix., (Copyright © 2018 Elsevier B.V. All rights reserved.)

This study reports a method for propoxycarbazone pesticide determination including its metabolite in food commodities (lettuce, beetroot, soybean meal and honey). Both compounds were extracted, and samples cleaned using a buffered QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method based on the AOAC Official Method, followed by ultra high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). Both matrix-matched calibration curves showed good linearity (R 2  = 0.99) within the tested ranges. Method performance was assessed on the basis of recovery and intra/inter-day precision studies at spiked concentrations of 10 (25) and 50 µg/kg (n = 5). Mean recovery rates were between 73 and 110%, while precision studies, assessed by relative standard deviation (RSD), were ≤20%. The limits of quantification (LOQ) were established as 10 or 25 µg/kg, depending on the matrix, which are low enough for monitoring residues at regulated maximum residue levels., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Magnetic hyperbranched polyamide amine (MHPA) was successfully prepared and applied as a QuEChERS adsorbent to the gas chromatograph-mass spectrometer (GC-MS) detection of organophosphorus pesticides (OPPs) in orange juice. Abundant in amino types and the structure of hyperbranched organic chains make MHPA to possess the clean-up function integrating classic clean-up agent primary secondary amine (PSA) with C 18 modified silica, and the magnetic property makes the operation easier and more time-saving. Compared the performance with classical clean-up agents of PSA and C 18 , better results were obtained with MHPA as adsorbent for the detection of 11 OPPs. Recoveries ranged from 75.2 to 116.2% with the relative standard deviation (RSD) of 4.1-18.9% and the limit of detection (LOD) of 0.74-8.16 ng/g. Results showed that using MHPA as adsorbent for QuEChERS sample preparation is an effective alternative with simplicity and rapidity., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Detection of meat from an animal species is required to avoid misleading food labels to consumers. Recently, we developed an easy-to-use molecular detection method by combining isothermal amplification and a DNA strip, referred to as DNA Strip. Here, we report our single-laboratory validation of DNA Strip to detect porcine DNA in beef meatballs. Our results showed that DNA Strip could specifically amplify the target of porcine DNA, with detection limit to 0.01% admixture of pork in beef meatballs. DNA Strip method was also robust because the use of heat block and laboratory water bath showed no significant differences and were comparable to the reference instrument. DNA Strip can detect porcine DNA within ca 1 h, including DNA extraction, DNA amplification, and detection. These results suggest that DNA Strip is applicable because it is easy to use and capable of detecting pork in beef meatballs with a greater detection limit.

Background: Biotin and folate are B-group vitamins that play a critical role in numerous metabolic reactions, and they are supplemented to infant and adult nutritional formulas as free biotin and folic acid., Objective: We describe a rapid method for the analysis of biotin and folic acid that is applicable to liquid milk, milk powders, infant formula, and milk-based nutritional products., Methods: Samples are autoclaved, centrifuged, filtered, and analyzed by HPLC-MS/MS, with quantitation accomplished by the internal standard technique., Results: The method was shown to be accurate, with acceptable spike recovery (biotin: 96.5-108.2%; folic acid: 92.6-104.4%), and no bias (α = 0.05) against either a certified reference material (biotin: P = 0.70; folic acid: P = 0.23) or established analytical method (biotin: P = 0.10; folic acid: P = 0.48) was found. Acceptable precision was confirmed with repeatability relative standard deviation (RSDr) and Horwitz ratio (HorRat) values (biotin: RSDr = 0.5-5.6%, HorRatr = 0.1-0.6; folic acid: RSDr = 2.0-3.1%, HorRatr = 0.3-0.5). Method detection limit and ruggedness experiments further demonstrated the suitability of this method for routine compliance testing., Conclusions: This rapid method is intended for use in high-throughput laboratories as part of the routine product compliance release testing of biotin and folic acid in the manufacturing of infant formulas and adult nutritional products.

A sensitive GC-MS method is reported for the determination of twelve polycyclic aromatic hydrocarbons (PAHs) in baby food. The sample preparation involves QuEChERS extraction combined with low-density solvent dispersive liquid-liquid microextraction (LDS-DLLME) and ultra-low temperature (-80 °C). Plackett-Burman screening design was employed to identify the main sample preparation variables that affect the extraction efficiency, such as the volume of toluene used in LDS-DLLME. The suitability of proposed method was verified by analytical selectivity, linearity in solvent and matrix-matched calibration curves and adequate recoveries (72-112%) and precision (RSD values ≤11%), under repeatability and within-laboratory reproducibility conditions. High analytical sensitivity was achieved for the monitoring of PAHs at the strict limit of 1 µg kg -1 fixed by the European Commission for baby foods. The validated method was applied to thirty-two commercial baby food samples, and the investigated PAHs were not detected in any sample., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

A silicon-based miniaturized sensor chip combined with an advanced microfluidic module for the simultaneous, label-free immunochemical determination of four allergens, bovine milk protein, peanut protein, soy protein, and gliadin, is presented. The sensor chip consists of an array of 10 broad-band Mach-Zehnder interferometers (BB-MZIs) monolithically integrated on silicon, along with their respective broad-band light sources. The BB-MZIs were biofunctionalized with the targeted allergens and their responses during immunoreaction were monitored by multiplexing their transmission spectra through an external miniaturized spectrometer. The assay is performed by running mixtures of calibrators or samples with the antibodies against the four allergens followed by an antispecies specific antibodies solution. Employing a fluidic module of nearly one-dimensional geometry, that provided for uniform delivery of the reagents, CV values <6% were achieved for the responses of the 10 BB-MZIs, allowing for reliable multianalyte determinations. The analysis is completed in 6.5 min, and the detection limits were 0.04 μg/mL for bovine k-casein, 1.0 μg/mL for peanut protein, 0.80 μg/mL for soy protein, and 0.10 μg/mL for gliadin. The assays were accurate (recoveries 88-118%) and repeatable (intra- and interassay CVs <7% for all four allergens). Finally, the sensor was evaluated by analyzing samples from a cleaning in place system (CIP) of a dairy industry and the results obtained were in good agreement with those received by the respective ELISAs. The analytical characteristics of the sensor combined with the short analysis time and the small chip size make the proposed system an ideal tool for on-site multianalyte determinations.

Foodborne illness outbreaks caused by the consumption of food contaminated with harmful bacteria has drastically increased in the past decades. Therefore, detection of harmful bacteria in the food has become an important factor for the recognition and prevention of problems associated with food safety and public health. Staphylococcus aureus is one of the most commonly isolated foodborne pathogen and it is considered as a major cause of foodborne illnesses worldwide. A number of different methods have been developed for the detection and identification of S. aureus in food samples. However, some of these methods are laborious and time-consuming and are not suitable for on-site applications. Therefore, it is highly important to develop rapid and more approachable detection methods. In the last decade, biosensors have gained popularity as an attractive alternative method and now considered as one of most rapid and on-site applicable methods. An overview of the biosensor based methods used for the detection of S. aureus is presented herein. This review focuses on the state-of-the-art biosensor methods towards the detection and quantification of S. aureus, and discusses the most commonly used biosensor methods based on the transducing mode, such as electrochemical, optical, and mass-based biosensors., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background/purpose: Among DNA-based techniques, polymerase chain reaction (PCR) is the most widely accepted molecular tool for the detection of pathogens. However, the technique involves several reagents and multiple pipetting steps that often lead to error-prone results. Additionally, the reagents entail a cold-chain facility to maintain their stability during storage and transportation. The main aim of the present study was to simplify the utility of a pre-optimized multiplex PCR format that was developed to detect toxigenic strains of Staphylococcus aureus by providing stable, pre-mixed, and ready-to-use master mix in a lyophilized formulation., Methods: Master mix containing all reagents except the template was lyophilized in the presence of an excipient lyoprotectant to achieve long-term stability without altering the sensitivity, specificity and PCR performance. Bromophenol blue was also included in the master mix to reduce the risk of external contamination during gel loading. The stability of lyophilized master mix was analyzed at different temperatures. The PCR performance was also examined after exposure of master mix to notable temperature fluctuations during transportation., Results: The shelf-life of lyophilized master mix was estimated to be 1.5 months at ambient temperature and 6 months at 4°C. Stability was unaffected by temperature fluctuations during transportation even in cold-chain-free conditions, thus reducing the cost required for cold storage., Conclusion: The sensitive, cost-effective, ready-to-use, and ambient temperature stable formulation could be implemented as a detection tool in food analysis and diagnostic laboratories and hospitals and for on-field application outside the laboratories, as well as for detection of toxigenic strains of S. aureus., (Copyright © 2016. Published by Elsevier B.V.)

The aim of the present work was to develop a rapid and interference-free method based on liquid chromatography-mass spectrometry (LC-MS) for the simultaneous determination of nine B-group vitamins in various energy drinks. A smart and green strategy that modeled the three-way data array of LC-MS with second-order calibration methods based on alternating trilinear decomposition (ATLD) and alternating penalty trilinear decomposition (APTLD) algorithms was developed. By virtue of "mathematical separation" and "second-order advantage", the proposed strategy successfully solved the co-eluted peaks and unknown interferents in LC-MS analysis with the elution time less than 4.5min and simple sample preparation. Satisfactory quantitative results were obtained by the ATLD-LC-MS and APTLD-LC-MS methods for the spiked recovery assays, with the average spiked recoveries ranging from 87.2-113.9% to 92.0-111.7%, respectively. These results acquired from the proposed methods were confirmed by the LC-MS/MS method, which shows a quite good consistency with each other. All these results demonstrated that the developed chemometrics-assisted LC-MS strategy had advantages of being rapid, green, accurate and low-cost, and it could be an attractive alternative for the determination of multiple vitamins in complex food matrices, which required no laborious sample preparation, tedious condition optimization or more sophisticated instrumentations., (Copyright © 2017 Elsevier B.V. All rights reserved.)

A rapid and reliable method to assay the total amount of tyrosol and hydroxytyrosol derivatives in extra virgin olive oil has been developed. The methodology intends to establish the nutritional quality of this edible oil addressing recent international health claim legislations (the European Commission Regulation No. 432/2012) and changing the classification of extra virgin olive oil to the status of nutraceutical. The method is based on the use of high-performance liquid chromatography coupled with tandem mass spectrometry and labeled internal standards preceded by a fast hydrolysis reaction step performed through the aid of microwaves under acid conditions. The overall process is particularly time saving, much shorter than any methodology previously reported. The developed approach represents a mix of rapidity and accuracy whose values have been found near 100% on different fortified vegetable oils, while the RSD% values, calculated from repeatability and reproducibility experiments, are in all cases under 7%. Graphical abstract Schematic of the methodology applied to the determination of tyrosol and hydroxytyrosol ester conjugates.

In developing countries in Asia, such as China, Vietnam, and Thailand, there is a strong need for the development of relatively rapid and low-cost bioassays for the determination of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (DL-PCBs) in environmental and food samples. These compounds are known to induce a variety of toxic and biological effects through their ligand-specific binding of the aryl hydrocarbon receptor (AhR). Indeed, several AhR-mediated reporter gene assays are widely used as prescreening tools for high-resolution gas chromatography/high-resolution mass spectrometry (HRGC-HRMS) analysis, which individually measures 17 PCDD/Fs and 12 DL-PCBs. In 2008, we have developed a new sensitive and rapid reporter gene assay using a genetically engineered stable cell line, designated DR-EcoScreen cells. The DR-EcoScreen assay using these cells has a number of great advantages of its sensitivity to 2,3,7,8-tetrachlorodibenzo-p-dioxin and its simple procedure, which shows little variance in the data (within CV 10 %) compared to other reporter gene assays. In this review, we summarize the application of the DR-EcoScreen assay to the determination of PCDD/Fs and DL-PCBs in ambient air samples, in fish and shellfish samples, and in flue gas samples from incinerators and provide potential usefulness of this bioassay for the determination of PCDD/Fs and DL-PCBs in various matrices.

Phenolic resin based activated carbon fibers (ACFs) were applied for the first time as a reversed-dispersive solid-phase extraction (r-DSPE) sorbent. A modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was applied to determine 26 pesticides (organophosphates, organochlorines, synthetic pyrethroids, and herbicides) in different complex matrices, including cauliflower, cucumber, banana, apple, wheat, and black gram. Different physicochemical characterization techniques were used to investigate the engineering and structural properties of the r-DSPE sorbent. All the chromatographic analyses were performed with a gas chromatograph equipped with an electron capture detector. The recoveries of all 26 pesticides were acceptable (70-120%), with relative standard deviations of less than 15%. The limit of detection and the limit of quantification were 1.13-5.48 ng/g and 3.42-16.60 ng/g, respectively. In the original QuEChERS method, primary secondary amine is extensively used as the r-DSPE sorbent in the cleanup process, but it is eightfold more expensive than the ACFs used in this study. Therefore, the modified QuEChERS method using ACFs during the cleanup process is more efficient, cheaper, and more robust to determine pesticides from different types of matrices, including vegetables, grains, and fruits, and ACFs could be used as a cost-effective alternative to primary secondary amine. Graphical Abstract Sample clean-up using PSA and ACF as r-DSPE sorbent in QuEChERS method.

The aim of the present work is to develop an efficient, simple and selective moreover cost-effective method for the extractive spectrophotometric determination of copper(II) by using the Schiff base 4-(4'-chlorobenzylideneimino)-3-methyl-5-mercapto-1, 2, 4-triazole [CBIMMT]. This chromogenic reagent forms a yellow coloured complex with copper(II) in acetate buffer at pH4.2. The copper(II) complex with ligand is instantly extracted into chloroform and shows a maximum absorbance at 414nm which remains stable for >48h. The composition of extracted complex is found to be 1:2 [copper(II): reagent] which was ascertained using Job's method of continuous variation, mole ratio method and slope ratio method. Under optimal conditions, the copper(II) complex in chloroform adheres to Beer's law up to 17.5μgmL -1 of copper(II). The optimum concentration range obtained from Ringbom's plot is from 5μgmL -1 to 17.5μgmL -1 . The molar absorptivity, Sandell's sensitivity and enrichment factor of the extracted copper(II) chelate are 0.33813×10 4 Lmol -1 cm -1 , 0.01996μgcm -2 and 2.49 respectively. In the extraction of copper(II), several affecting factors including the solution pH, ligand concentration, equilibrium time, effect of foreign ions are optimized. The interfering effects of various cations and anions were also studied and use of masking agents enhances the selectivity of the method. The chromogenic sulphur containing reagent, 4-(4'-chlorobenzylideneimino)-3-methyl-5-mercapto-1, 2, 4-triazole has been synthesized in a single step with high purity and yield. The synthesized reagent has been successfully applied first time for determination of copper(II). The reagent forms stable chelate with copper(II) in buffer medium instantly and quantitatively extracted in chloroform within a minute. The method is successfully applied for the determination of copper(II) in various synthetic mixtures, complexes, fertilizers, environmental samples such as food samples, leafy vegetables, and water samples. The results are compared with those obtained with a reference procedure. Good agreement was attained. All the obtained results are indicative of a convenient, fast method for the extraction and quantification of micro levels of copper(II) from various environmental matrices without use of sophisticated instrumentation and procedure. The method showed a relative standard deviation of 0.42%., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The American diet has changed dramatically since 1958, when Congress gave the United States Food and Drug Administration (FDA) the authority to ensure the safety of chemicals in food. Since then, thousands of chemicals have entered the food system. Yet their long-term, chronic effects have been woefully understudied, their health risks inadequately assessed. The FDA has been sluggish in considering scientific knowledge about the impact of exposures-particularly at low levels and during susceptible developmental stages. The agency's failure to adequately account for the risks of perchlorate-a well-characterized endocrine-disrupting chemical-to vulnerable populations is representative of systemic problems plaguing the regulation of chemicals in food. Today, we are faced with a regulatory system that, weakened by decades of limited resources, has fallen short of fully enforcing its mandates. The FDA's inability to effectively manage the safety of hundreds of chemicals is putting our children's health at risk.

In this study, a QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method, optimized by a 2 3 full factorial design, was developed for the determination of 72 pesticides in plant parts of carrot, corn, melon, rice, soy, silage, tobacco, cassava, lettuce and wheat by ultra-high-performance liquid chromatographic tandem mass spectrometry (UHPLC-MS/MS). Considering the complexity of these matrices and the need of use calibration in matrix, a new calibration approach based on single level standard addition in the sample (SLSAS) was proposed in this work and compared with the matrix-matched calibration (MMC), the procedural standard calibration (PSC) and the diluted standard addition calibration (DSAC). All approaches presented satisfactory validation parameters with recoveries from 70 to 120% and relative standard deviations≤20%. SLSAS was the most practical from the evaluated approaches and proved to be an effective way of calibration. Method limit of detection were between 4.8 and 48μgkg -1 and limit of quantification were from 16 to 160μgkg -1 . Method application to different kinds of plants found residues of 20 pesticides that were quantified with z-scores values≤2 in comparison with other calibration approaches. The proposed QuEChERS method combined with UHPLC-MS/MS analysis and using an easy and effective calibration procedure presented satisfactory results for pesticide residues determination in different crop plants and is a good alternative for routine analysis., (Copyright © 2017 Elsevier B.V. All rights reserved.)

There is an increasing demand for rapid, sensitive, and low cost analytical methods to routinely screen antibiotic residues in food products. Conventional detection of antibiotics involves sample preparation by liquid-liquid or solid-phase extraction, followed by analysis using liquid chromatography-mass spectrometry (LC-MS), capillary electrophoresis (CE), or gas chromatography (GC). The process is labor-intensive, time-consuming, and expensive. In this study, we developed a new analytical method that combines magnetic molecularly imprinted polymer (MMIP)-based sample preparation with surface-enhanced Raman spectroscopy (SERS)-based detection for quantitative analysis of cloxacillin in pig serum. MMIP microspheres were synthesized using a core-shell technique. The large loading capacity and high selectivity of the MMIP microspheres enabled efficient extraction of cloxacillin, while the magnetically susceptible characteristics greatly simplified sample handling procedures. Low cost and robust SERS substrates consisting of vertical gold capped silicon nanopillars were fabricated and employed for the detection of cloxacillin. Quantitative SERS was achieved by normalizing signal intensities using an internal standard. By coherently combining MMIP extraction and silicon nanopillar-based SERS biosensor, good sensitivity toward cloxacillin was achieved. The detection limit was 7.8 pmol. Cloxacillin recoveries from spiked pig plasma samples were found to be more than 80%.

Smartphone biosensors could be cost-effective, portable instruments to be used for the readout of liquid colorimetric assays. However, current reported smartphone colorimetric readers have relied on photos of liquid assays captured using a camera, and then analyzed using software programs. This approach results in a relatively low accuracy and low generality. In this work, we reported a novel smartphone colorimetric reader that has been integrated with an ambient light sensor and a 3D printed attachment for the readout of liquid colorimetric assays. The portable and low-cost ($0.15) reader utilized a simplified electronic and light path design. Furthermore, our reported smartphone colorimetric reader can be compatible with different smartphones. As a proof of principle, the utility of this device was demonstrated using it in conjunction with an enzyme-linked immunosorbent assay to detect zearalenone. Results were consistent with those obtained using a professional microplate reader. The developed smartphone colorimetric reader was capable of providing scalable, cost-effective, and accurate results for liquid colorimetric assays that related to clinical diagnoses, environment pollution, and food testing. Graphical abstract A novel smartphone colorimetric reader that has been integrated with an ambient light sensor and a 3D printed attachment for the readout of liquid colorimetric assays.

In this research, the manual two-step QuEChERS approach has been streamlined and automated into a one-step method using a cleanup tube fitted within an extraction tube. A novel automatic QuEChERS combination have been developed to simplify the QuEChERS procedures and improve sample preparation efficiency. This combination integrates QuEChERS procedures into a single run via the use of a vortex vibration-centrifuge device and a centrifuge filtration tube. To validate the efficiency of our automatic QuEChERS device, 270 pesticides were analyzed in plant origined foods including celery, tomatoes, leeks, eggplants, grapes, corn, green tea, and soybean oil using this automatic platform. The results were then compared with those obtained using the manual QuEChERS method. Different parameters were validated and compared including recovery, linearity, repeatability and limits of quantification (LOQ). Satisfactory results, comparable to results obtained using the manual QuEChERS method were obtained. The average recoveries ranged between 70% and 120% for most pesticides with associated relative standard deviations (RSDs) <20% (n=5) indicating satisfactory accuracy and repeatability. An LOQ of 2μg/kg was obtained for most pesticides present in celery and corn matrices, and the correlation coefficients (r 2 ) were >0.990 within a linearity range of 2-500μg/kg. Compared to manual QuEChERS, this novel automatic QuEChERS device and combination could significantly improve the sample preparation efficiency for the multiresidue analysis of pesticides., (Copyright © 2017. Published by Elsevier B.V.)

The substitution of ewe milk with more economic cow milk is a common fraud. Here we present a capillary electrophoresis method for the quantification of ewe milk in ovine/bovine milk mixtures, which allows for the rapid and inexpensive recognition of ewe milk adulteration with cow milk. We utilized a routine CE method for human blood and urine proteins analysis, which fulfilled the separation of skimmed milk proteins in alkaline buffer. Under this condition, ovine and bovine milk exhibited a recognizable and distinct CE protein profiles, with a specific ewe peak showing a reproducible migration zone in ovine/bovine mixtures. Based on ewe specific CE peak, we developed a method for ewe milk quantification in ovine/bovine skimmed milk mixtures, which showed good linearity, precision and accuracy, and a minimum amount of detectable fraudulent cow milk equal to 5%., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The development of novel and high-tech solutions for rapid, accurate, and non-laborious microbial detection methods is imperative to improve the global food supply. Such solutions have begun to address the need for microbial detection that is faster and more sensitive than existing methodologies (e.g., classic culture enrichment methods). Multiple reviews report the technical functions and structures of conventional microbial detection tools. These tools, used to detect pathogens in food and food homogenates, were designed via qualitative analysis methods. The inherent disadvantage of these analytical methods is the necessity for specimen preparation, which is a time-consuming process. While some literature describes the challenges and opportunities to overcome the technical issues related to food industry legal guidelines, there is a lack of reviews of the current trials to overcome technological limitations related to sample preparation and microbial detection via nano and micro technologies. In this review, we primarily explore current analytical technologies, including metallic and magnetic nanomaterials, optics, electrochemistry, and spectroscopy. These techniques rely on the early detection of pathogens via enhanced analytical sensitivity and specificity. In order to introduce the potential combination and comparative analysis of various advanced methods, we also reference a novel sample preparation protocol that uses microbial concentration and recovery technologies. This technology has the potential to expedite the pre-enrichment step that precedes the detection process., Competing Interests: The authors declare no conflict of interest.

The aim of investigation was to evaluate a traceability system to detect industrial chicken meat among indigenous products, considering issues that could affect assignment accuracy. The dataset included 2 Italian indigenous meat breeds, namely Bionda Piemontese (2 ecotypes) and Bianca di Saluzzo, one broiler line, and 3 layer lines. Assignment tests were performed using a standard panel of 28 microsatellite loci. To evaluate effects of inbreeding and substructure on assignment accuracy, a simulated dataset was prepared. Broilers and layers belong to homogeneous populations and never enter the clusters of indigenous breeds. Ambiguity or misallocation are expected between the Bionda ecotypes and between the 2 indigenous breeds, but it is unlikely that niche products provided by Bionda and Bianca will compete with one another. Non-random mating reduces accuracy, but only populations having weak genetic differentiation are involved, namely those that are less interesting to discriminate. The dataset can be used as a reference population to distinguish commercial meat from indigenous meat with great accuracy. Misallocations increase as number of loci decreases, but only within or between the indigenous breeds. A subpanel of the most resolving 14 loci keeps sufficient informative content to provide accuracy and to correctly allocate additional test samples within the reference population. This analytical tool is economically sustainable as a method to detect fraud or mislabeling. Adoption of a monitoring system should increase the value of typical products because the additional burden of molecular analyses would improve commercial grade and perception of quality., (© 2017 Poultry Science Association Inc.)

A novel method for indirect determination of MCPD esters levels in lipid samples has been developed. The method is based on combination of extraction and derivatization in the same sample preparation step. It is achieved by the application of diethyl ether as extraction solvent for isolation of analytes released from esterified forms from the water phase and as dilution solvent for solid PBA - the derivatization agent. It is a noteworthy improvement of recommended indirect approaches available in the literature because such steps as sample clean-up, multiple liquid-liquid extractions, and preconcentration are excluded in the proposed solution. In this way, the developed procedure is shortened and simplified. Such an approach also minimizes the utilization of organic solvents; therefore, it is in accordance with the principles of "green analytical chemistry." In spite of the fact that the step of sample clean-up is omitted, no deterioration in GC-MS system performance was observed. Equivalence testing of the developed procedure and AOCS cd 29b-13 official method (SGS) has been conducted. It was concluded that results obtained by both methods do not significantly differ statistically. The procedure has been applied to determination of MCPD esters concentrations in lipid fractions isolated by accelerated solvent extraction technique from such foodstuffs as bakery products, salty deep-fried snacks, and instant products. In all investigated samples, the level of bound MCPD was elevated. Additionally, for both procedures, the environmental impact (with the use of analytical Eco-scale) and uncertainty budget have been assessed and compared.

In this work, a conducting porous polymer hydrogel-based electrochemical sensor has been developed for rapid detection of copper (II) ions (Cu 2+ ). The polymer (termed as PAAM/PA/PDA) hydrogel is prepared through multi-interactions of the monomers dopamine (DA), acrylamide (AAM) and phytic acid (PA) under mild ambient conditions: the AAM polymerizes through free-radical polymerization, DA occurs poly coupling reaction, and PA crosslinks polydopamine (PDA) and polyacrylamide (PAAM) by hydrogen bonds. The three dimensional (3D) network nanostructured PAAM/PA/PDA hydrogel not only provides a large surface area for increasing the amount of immobilized molecules/ions, but also exhibits a good conductivity. The PAAM/PA/PDA hydrogel-based electrochemical sensor exhibits a low detection limit (1nmolL - 1 , S/N=3) and wide linear range (from 1nmolL - 1 to 1µmolL -1 ) for Cu 2+ detection in aqueous samples. Furthermore, the Cu 2+ can be sensitively detected by the electrochemical sensor in different sample matrices, indicating that the electrochemical sensor could be used to monitor Cu 2+ with reasonable assay performance in practical samples. The PAAM/PA/PDA hydrogel also exhibits a good capacity to remove Cu 2+ (231.36±4.70mgg -1 ), which is superior to those of other adsorption materials reported in the literature. The facile synthesized PAAM/PA/PDA hydrogel provides a novel and regenerable platform for monitoring and removing Cu 2+ in real samples., (Copyright © 2016 Elsevier B.V. All rights reserved.)