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Accumulation of hexavalent chromium in the environment affects our ecosystem. Physico-chemical treatment did not solve the problem, due to high requirement of operational costs & energy, insolubility of Cr (VI) at any pH & sludge accumulation. The study aim is screening and evaluating fungi for chromium biosorption for mycoremediation. Soil and effluent sample were collected. PDA media was used for fungi purification. Fungal chromium tolerance evaluation and optimization was conducted at pH (4, 7, 10), T0 (25, 27.5, 35 °C), Cr concentration (5000–25000 ppm) using Full Factorial experimental design. Spore count, biomass production, Cr tolerance index, mycelia growth were evaluated. Flame Absorptive Spectrophotometer was used for quantification of fungal chromium removal. Fungi species were identified by MALDI-TOF. Fungi growth & degradation of tannery shaving waste was evaluated. The result revealed 6 potential fungi, T. longibrachiatum, T, koningii, A. niger, G. candidum, P. rubens, T. orientale were identified. Optimium mean biomass & spore count were 0.514 ± 0.051& 1.39 ± 0.038 at pH4 and 27.5 °C respectively. MTL test indicate that Trichoderma species, A. niger & P. rubens survive up to 10,000 ppm, 15, 000 ppm & 20,000 ppm respectively. FAAS analysis of fungi chromium removal from aqueous media result indicate that A. niger (99%). T. longibrachiatum (85%) and P. ruben (84.6%). These 6 fungi are efficient in tannery shaving waste degradation but A. niger was superior in spore count 15.1 Log/mL and 7 g substrate weight loss. In conclusion three fungi have high chromium tolerance and removal capacity and shaving waste degradation promising for mycoremediation. [Display omitted] • Chromium (VI) & tannery shaving waste severely pollute our environment. • Eco friendly mycoremediation approach for Chromium pollution is advantageous over conventional methods. • Aspergillus niger , Trichoderma longbranchium, and Pencilium rubens showed best Chromium biosorption capacity. • Tannery shaving waste used as substrate for fungal cultivation for large scale & chromium recovery. [ABSTRACT FROM AUTHOR]

MnAl layered double hydroxide hybrid with magnetic-multiwalled carbon nanotubes was synthesized by a hydrothermal method and used for the extraction of Pb(II) (lead) from spices and water samples in the dispersive solid phase microextraction (dSPμE) technique using FAAS. The as-prepared adsorbent MMWCNTs@MnAl-LDH was characterized by XRD, FTIR, EDX, and SEM techniques. Various analytical parameters were optimized, including pH 8, adsorbent dosage of 5 mg, HNO 3 eluent concentration of 1 mol L−1, eluent volume of 3 mL, eluent time of 60 s, and sample volume of 20 mL, for quantitative lead recoveries, with an LOD of 0.314 μg L−1, an LOQ of 1.048 μg L−1, and PF of 11.53. Under the optimized conditions, the linearity ranges from 0.5 to 500 μg L−1 (R2 = 0.9997). For the validation test of the established dSPμE procedure, Certified reference materials (CRMs) were used, yielding satisfactory recovery results ranging from 97.8 to 102.7 %. The method was applied to determine lead in turmeric, tap water, and industrial water samples. [Display omitted] • Preparation of a novel adsorbent MnAl-Ldh hybrid with magnetic multiwalled carbon nanotubes by using the hydrothermal method. • A new adsorbent has been used for the extraction of lead from spices (tumeric) and water samples. • Lead has been investigated with improved analytical parameters, via FAAS; without any foreign ions effect. • The major advantages. of the developed method was found effective with low sample volume and low adsorbent dosage. [ABSTRACT FROM AUTHOR]

[Display omitted] • Preparation of a novel adsorbent functionalized nanodiamonds with NiCoFe-LDH, by using the hydrothermal method. • Nanodiamonds@NiCoFe-LDH has been used for the dispersive solid-phase microextraction for lead Pb(II). • Pb(II) was investigated at low LOD levels via FAAS, without any foreign ions interfering. • The developed method was found effective with low sample volume and low adsorbent amount. • The method was successfully applied to commercial juice samples of different brands. A new solid phase microextraction (SPME) method utilizing nanodiamonds@NiCoFe-LDH for the pretreatment and extraction of Pb(II) before sample determination through FAAS was developed. NiCoFe-LDH was synthesized by using a hydrothermal synthesis technique and then combined with functionalized nanodiamonds. For the characterization of nanodiamonds@NiCoFe-LDH composite, FT-IR, FE-SEM, and XRD were utilized. The analytical parameters (pH level, amount of sorbent, concentration of eluent, volumes of sample and eluent, desorption time), i.e., pH = 8.0, 5.0 mg, 0.5 mol/L, 50 mL, 1.5 mL, and 0.5 min, respectively, were studied to set the maximum efficiency of the developed method. Additionally, matrix effects were taken into consideration during the evaluation process using the standard addition method. The limit of detection (LOD) and the preconcentration factor (PF) were obtained as 0.62 ng mL-1 and 25, respectively. To confirm the accuracy of the newly developed method, certified reference materials (CRMs) (NIST SRM 1515 apple leaves and BCR-505 estuarine water) were employed. %RSD was calculated as 2.0–8.0. The optimized method was successfully implemented to quantify Pb(II) in commercially available fruit juices of various brands and flavors procured from local markets in Kayseri, Turkey. Compared to previously reported methods, the developed method demonstrated exceptional sensitivity, achieving a remarkably low LOD. [ABSTRACT FROM AUTHOR]

This work presents, a simple and quick method derived from surfactant-based emulsification microextraction to determine gold ions in environmental samples by using flame atomic absorption spectrometry (FAAS). Cetyltrimethylammonium bromide (CTAB) is used as a cationic surfactant agent in the extraction procedure. According to this method, the extraction solvent was dispersed into aqueous samples, and emulsification had occurred with the assistance of hand rinsing. The ion pairs formed between AuC14 - and CTAB is extracted into the chloroform phase without the use of a dispersive solvent. Several experimental parameters such as effect of pH, concentration of the surfactant, etc. were investigated. The calibration curve was found to be linear in the range from 4 to 500 µg L-1, the limit of detection was 1.1 µg L-1 and the enrichment factor was 80. The relative standard deviation for 10 replicates was observed to be 2.2% with 25 µg L-1 of gold. The quantitative recoveries of gold in water and ore samples were in the range of 96%-99%. The results show that this microextraction procedure is a selective, rapid, simple and low-cost method for the separation/preconcentration of gold in water and ore samples. [ABSTRACT FROM AUTHOR]

Portugal produces unique wines at special demarcated regions (Protected Geographical Indications – PGI) whose quality is increasingly recognized worldwide. The uniqueness of the wines produced at each PGI demands the development of methods that can ensure their quality and authenticity. In this study, it was investigated whether the wines from different Portuguese PGI could be differentiated based on their elemental profile. For this purpose, 60 red and white wine samples, from 6 different PGI were analysed for a wide panel of elements (53) by FAAS and ICP-MS. Discriminant analysis was used to find the elements with discriminant power. Despite the limited set of samples, the results showed that the concentration of several elements (e.g. Ca, Mn, Co, Zn, Br, Sr, Cd, W and Tl) was significantly different among wines and could reliably discriminate the wines from the different PGI regions. • 60 Portuguese red and white wines from 6 different Protected Geographical Indications (PGI) were analysed. • A wide panel (53) of elements (macro and trace elements) was determined. • Discriminant analysis was used to evaluate if the wines could be grouped according to their PGI. • Some elements (Ca, Li, Mn, Co, Zn, Br, Sr, Cd, Ba, W and Tl) showed discriminant power. • Daily intake of essential and toxic elements was also estimated. [ABSTRACT FROM AUTHOR]

A new amine based microextraction procedure has been established for the separation and preconcentration of lead (II). N , N -dimethyl-n-octylamine was used as extraction solvent and chelating agent for lead (II). Microsampling flame atomic absorption spectrometry was used for the determination of lead. The analytical parameters including pH, amounts of N , N -dimethyl-n-octylamine, sample volume etc. were optimized. The influences of the matrix components were also investigated. The validation of the procedure was done by the analysis of TMDA 64.2 certified reference material. The Limit of detection (LOD) of developed method was 2.6 μg L−1. The developed microextraction procedure was successfully applied to natural water samples. • A new amine based microextraction procedure has been established for the separation and preconcentration of lead. • N , N -dimethyl-n-octylamine was used as extraction solvent and chelating agent for lead. • The effects of analytical parameters were systematically investigated and optimized. • The method has been applied to the analysis of lead in water samples. [ABSTRACT FROM AUTHOR]

In the study, a simple and green vortex assisted-ionic liquid based dispersive liquid liquid microextraction (VA-IL-DLLM) combined with flame atomic absorption spectrometry (FAAS) was developed for the extraction and determination of nickel (Ni) and cobalt (Co) in chocolate-based samples. An ultra-hydrophobic ionic liquid (IL), 1-hexyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate, [C 6 mim][FAP], was chosen as extraction solvent. The method is selectively based on chelate formation between Ni(II)/Co(II) ions and ninhydrin (2,2-dihydroxyindane-1,3-dione) at pH 9.0, and then simultaneous extraction of the formed complexes into the micro-drops of IL, [C 6 mim] [FAP]. Extraction parameters (pH, the IL amount, chelating ligand concentration, vortex time, volume of dispersive solvent, and effect of interference ions) were evaluated and optimized. Under optimized conditions, the method was as follows; linear working ranges were within the 1.0–350 μg L−1 and 0.7–400 μg L−1 for Ni and Co, respectively. The limits of detections (3 × s blank /m, n:10) were 0.3 μg L−1 for Ni(II) and 0.2 μg L−1 for Co(II) with relative standard deviation <3.1% for real samples. The method was validated by analysis of two standard reference materials (SRMs), and recovery tests based on spiking at two levels. Lastly, the method was reliably applied for the determination of trace Ni and Co in chocolate-based samples, with amounts in range of 1.5–192.7 μg L−1 and in range of 3.8–152 μg L−1, respectively. • Ni(II) and Co(II) ions were complexed with ninhydrin at pH 9.0. • Provided the fast extraction of analytes by help of vortex without heating process. • A simple and innovative VA-IL-DLLM procedure was applied to chocolate-based samples. • The method allows the detection of Co(II) and Ni(II) at levels of 0.2 and 0.3 μg L−1, respectively. • The amounts of Ni(II) and Co(II) in selected samples were reliably determined by help of FAAS. [ABSTRACT FROM AUTHOR]

Abstract Soil organic matter (SOM) plays an important role in environmental sustainability, since it is involved in carbon and nutrient cycling. Consequently, it is a key factor to consider in studies concerning global climate change and agronomy. Among the main components of SOM are humic substances (HS), which are divided, according to their solubility, into humic acid (HA), fulvic acid (FA), and humin (HU) fractions. Study of the chemical properties of this organic matter is important for understanding the biogeochemical processes occurring in the soil. The aim of this work was to determine the metals iron (Fe) and aluminum (Al), using flame atomic absorption spectrometry (FAAS) and laser-induced breakdown spectroscopy (LIBS), in order to elucidate the role of organic matter in the transport of these metals in Amazonian soils. The results showed that FA was important for Al, while the HA fraction was more selective towards Fe. The translocations of these metals to deeper profiles in two different soils involved either young and less humified organic matter, or older organic matter with a low degree of humification. Therefore, these two humic fractions were involved in the process of soil podzolization, with FA having a predominant role in the transport of Al, while HA was mainly responsible for the transport of Fe. Highlights • Humic fractions were involved in the soil podzolization process. • Fulvic acids were important for Al. • Humic acids were more selective towards Fe. • Translocations of these metals to deeper profiles in two different organic matters • LIBS as potential technique of analysis for processes of formation of Amazonian soils [ABSTRACT FROM AUTHOR]

In the present study, core–shell Fe 3 O 4 polydopamine nanoparticles were synthesized and used for the first time as an adsorbent for the vortex assisted magnetic dispersive solid phase extraction of copper from food samples. After elution, copper in the solutions was determined by FAAS. The adsorbent was characterized using X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller surface area, and zeta potential measurements. Various parameters affecting the magnetic dispersive solid-phase extraction were evaluated. The optimum pH and magnetic adsorbent amount were found to be 5 and 40 mg, respectively. Elution was made by 3 mL of 2 mol L −1 HNO 3 .The major advantage of the method is the fast equilibration during adsorption without the need for vortexing or shaking. The preconcentration factor and detection limit of the method were found to be 150 and 0.22 mg L −1 , respectively. The precision (as RSD%) and adsorption capacity of the method were 3.7% and 28 mg g −1 , respectively. The method was successfully verified by analyzing four certified reference materials (SPS-WW1 Batch 114 Wastewater, TMDA-53.3 Lake water, BCR-482 Lichen and 1573a Tomato Leaves) and by addition/recovery tests of copper standard solution in organic baby food, muesli, macaroni, honey, and milk samples. [ABSTRACT FROM AUTHOR]

This study presents the coupling of slotted quartz tube with flame atomic absorption spectrometry for the determination of cadmium after preconcentration with dispersive liquid–liquid microextraction. A bipyridine ligand was used to form covalent cadmium complex, and the formation yield was increased by optimizing parameters such as pH/amount of buffer solution and ligand concentration. Parameters that influence the extraction output and slotted quartz tube efficiency were also optimized to increase the sensitivity. The optimization steps added up to give about 135 times increased sensitivity in comparison to the conventional flame atomic absorption spectrometry. The limits of detection and quantification obtained under optimum experimental conditions were 0.31 and 1.04 µg L −1 , respectively. Applicability of the method was tested on lake water, municipal wastewater and onion samples spiked at different concentrations. Percentage recoveries were found to be between 84 and 105% for the samples, and matrix matching was used to obtain 98.6% recovery for onion spiked at 20 µg L −1 . [ABSTRACT FROM AUTHOR]

Air quality in urban areas is generally poor especially at traffic intersections and roadsides due to continuous vehicular emissions comprising poly aromatic hydrocarbons, heavy metals, benzene, diesel soot etc. The objective of this study was to compare the primary DNA damage in traffic police wardens occupationally exposed to airborne Cd and Zn (exposed group) and educational institution with negligible exposure to airborne Cd and Zn (control group). Blood levels of Cd and Zn in traffic police wardens and control group were determined by Flame Atomic Absorption Spectroscopy (FAAS) and DNA damage was assessed by using Comet assay. The results of this study showed significantly higher amount of Cd (0.18 ± 0.06 mg L −1 ) and Zn (4.87 ± 1.34 mg L −1 ) in the blood of traffic police wardens as compared to control group and according to World Health Organization, these values are 18 and 3 times more to the permissible limit of Cd and Zn respectively in human blood. In addition, significantly higher numbers of DNA damaged cells (28 ± 13%) were observed in traffic police wardens as compared to control group (3.6 ± 2%). Comet tail length was found to be doubled (4.7 ± 1.7 μm) in traffic police wardens as compared to the control group (2 ± 1.2 μm). These results could be linked to the concentrations of Cd and Zn in blood of traffic police wardens. In conclusion, our results showed that accumulation of Cd and Zn was higher in traffic police wardens due to air pollution (Zn and Cd) and has more damaged DNA of traffic police wardens in Pakistan. [ABSTRACT FROM AUTHOR]

Many people after 50 year of life suffer pains caused by osteoarthritis (OA), which make their life difficult and painful. There is a probable association of OA with the concentration of certain elements in body fluids. Therefore the aim of the study was to relate the level of essential elements in synovial fluids of patients with OA with the treatment using antiarthritic drugs. Thus, flame-atomic absorption spectrometry was used to determine the concentrations of Fe, Zn, Cu, Mn, Na, K, Ca and Mg in 74 samples of synovial fluids taken from 36 patients. Prior to analysis, the samples of synovial fluids were centrifuged and obtained supernatants were digested by microwave technique. It was found that the level of investigated essential elements was differentiated in patients suffering with OA. High correlation between Zn and K, Na and K, as well as Cu and Mn were revealed. Based on cluster analysis, synovial fluids of patients treated with Diprophos, Euflexxa and Synocrom, can be found almost in all clusters. ANOVA has shown that there is a significant difference between Na level in synovial fluids of patients treated with antirheumatic drugs, and those who were not treated. For the patients treated with Euflexxa, similar relations for Ca and K exist. Principal component analysis has shown that essential elements responsible for variability within studied samples, are Ca, Mg, Cu, Mn and Fe. However, there were no statistically significant relations between the studied macro- and microelements, and treatment using specific preparations. [ABSTRACT FROM AUTHOR]

In this paper, the tyre-based activated carbon solid phase extraction (SPE) method was successfully developed for simultaneous preconcentration of metal ions in the model and real water samples before their determination using flame atomic absorption spectrometry (FAAS). The activation of carbon was achieved by chemical activation and the tyre-based activated carbon was used as a sorbent for solid phase extraction. The prepared activated carbon was characterized using the scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET), and Fourier Transform Infrared spectroscopy. Moreover, optimization of the proposed method was performed by the two-level full factorial design (FFD). The FFD was chosen in order to fully investigate the effect of the experimental variables (pH, eluent concentration and sample flow rate) that significantly influence the preconcentration procedure. In this model, individual factors are considered along with their interactions. In addition, modelling of the experiments allowed simultaneous variation of all experimental factors investigated, reduced the required time and number of experimental runs which consequently led to the reduction of the overall required costs. Under optimized conditions, the limits of detection and quantification (LOD and LOQ) ranged 0.66–2.12 μg L −1 and 1.78–5.34 μg L −1 , respectively and the enrichment factor of 25 was obtained. The developed SPE/FAAS method was validated using CWW-TM-A and CWW-TM-B wastewater standard reference materials (SRMs). The procedure showed to be accurate with satisfactory recoveries ranging from 92 to 99%. The precision (repeatability) was lower than 4% in terms of the relative standard deviation (%RSD). The developed method proved to have the capability to be used in routine analysis of heavy metals in domestic and industrial wastewater samples. In addition, the developed method can be used as a final step (before being discharged to the rivers) in wastewater treatment process in order to keep our water bodies free from toxic metals. [ABSTRACT FROM AUTHOR]

In this work, a polyurethane foam (PUF) functionalized with phenylfluorone (PUF-PF) was packed in a minicolumn and used as an on-line preconcentration system for cadmium and copper determination in water samples. The experimental conditions (both chemical and physical) were optimized to achieve the highest sensitivity. A study of possible ion interference on the retention of cadmium and copper was also performed. The enrichment factors obtained were 14 and 16 for copper and cadmium, respectively, using a preconcentration time of 1 min. The proposed system allowed the determination of metals with limits of detection (3 σ ) of 0.8 and 0.3 μg L − 1 for Cu(II) and Cd(II), respectively. The precision of the procedures was also calculated as 7.6% for Cu(II) (at 25 μg L − 1 ) and 4.0% for Cd(II) (at 10 μg L − 1 ). The limits of quantification obtained were 2.6 and 0.8 μg L − 1 for Cu(II) and Cd(II), respectively. Cadmium and copper contents in water samples (from rivers and swimming pools) were determined by applying the proposed procedure. In these samples, recovery tests were conducted in order to evaluate the accuracy of the method; the recovery percentages varied between 83 and 109%. [ABSTRACT FROM AUTHOR]

Lead is a toxic metal which affects human health badly due to its high toxicity. The wide application range of lead causes environmental contamination of air, water and soil. Flame atomic absorption spectrometry is one of the simple and economical instrument used for the determination of heavy metals, but it has low sensitivity due to low sample introduction efficiency. In this study, a sensitive analytical method was developed by using T-shaped slotted quartz tube as an atom trap unit to get lower detection limit for lead. The trapped atoms were released using hydrogen gas which supplies reducing environment in T-SQT-AT-FAAS system. Factors such as trapping period, sample and fuel flow rates were optimized to obtain high sensitivity. Under the optimum conditions, limits of detection and quantitation were found to be 0.6 and 2.1 μg L − 1 , respectively. Accuracy of the developed method was checked and results found under the optimum conditions agreed with the certified value of coal fly ash standard reference material. The developed method was applied to water samples to figure out its suitability. [ABSTRACT FROM AUTHOR]

[Display omitted] • Determination of Cd2+ contents in sediments, tobaccos and mushrooms by FAAS. • High repeatable microextraction values by automated syringe discharge system. • Hydrophobic immiscible chelating fluid (HICF) based micro-extraction of Cd2+. • Selective, extraordinary and superior approach for micro-extraction of Cd2+. • Simultaneous chelation, micro-extraction and masking with only one fluid. The novel, extraordinary and highly selective separation and preconcentration approach based on hydrophobic immiscible chelating fluid (HICF) having superior features (simultaneous chelation, extraction and masking) and combined with automatized syringe discharge system by peristaltic pump was established firstly for simultaneous chelation and micro-extraction of Cd2+. Mixture of tetra butyl ammonium iodide, tetra butyl ammonium fluoride, n-pentanol (1:1:10) and dithizone were used to formulate HICF. The parameters including pH, chelator concentration on both characteristic of HICF and extraction of Cd2+, time of vortex mixing, amount of HICF and sample volume were optimized and investigated in detail. The optimized method has permitted to obtain 25 preconcentration factor (PF) and detect the lowest cadmium concentration having 2.1 µg L−1 (LOD) in the aqueous solution. Interference effect of defiant metal cations was investigated in detail. The dynamic range of the method (LDR) was obtained linearly between 7.2 and 1500 µg L−1. Relative standard deviations (% RSD) were below than % 4.2 throughout the experiments. The envisaged possible extraction mechanisms were explained. The proposed novel method was validated with applications of multiple analyte-addition recovery tests in water samples (tap, lake and natural spring water) and analysis of standard reference material (UME EnvCRM 03 Elements in Soil). Quantitative satisfactory recovery values changing between 98 and 106 % were obtained. Validated method was also applied to determine Cd contents of sediment, mushroom and raw tobacco samples. The main advantage of HICF is that it contains masking and chelating agents and extraction solvent in only one liquid. Therefore, possible concentration and volume errors were minimized by single micropipette injection that ensured time saving and simplicity for applicability of the method by the analysts. Moreover, automated syringe discharge system has provided repeatable and precision extraction results. [ABSTRACT FROM AUTHOR]

• Glycogen metabolism was mainly affected by Karlodinium veneficum. • FAAs content decreased in clam feeding on Karlodinium. • Anabolic metabolism of carnosine was initiated by feeding on Karlodinium. • K. veneficum affect the production of endogenous C 18 PUFA precursors. • VOCs composition differed by feeding different microalgae. • High density of Karlodinium affected the taste and odor. Phytoplankton composition is an important factor affecting the growth and physiological biochemical characteristics of filter-feeding bivalves. With the increasing trend in dinoflagellate biomass and blooms in mariculture areas, how the physio-biochemical traits and seafood quality of the mariculture organism are affected by the dinoflagellates, especially those at nonfatal levels, is not well understood. Different densities of two Karlodinium species, namely K. veneficum (KV) and K. zhouanum (KZ), mixed with high quality microalgal food Isochrysis galbana was applied in feeding manila clam Ruditapes philippinarum in a 14-day temporary culture, to comparatively study how the critical biochemical metabolites such as glycogen, free amino acids (FAAs), fatty acids (FAs), volatile organic compounds (VOCs) in the clam were affected. The survival rate of the clam showed dinoflagellate density and species specificity. The high-density KV group inhibited survival to 32% lower than that of the pure I. galbana control, respectively, while KZ at low concentrations did not significantly affect the survival compared with the control. In the high-density KV group, the glycogen and FAA contents decreased (p < 0.05), indicating that energy and protein metabolism were significantly affected. Amount of carnosine (49.91 ± 14.64 to 84.74 ± 8.59 μg/g of muscle wet weight) was detected in all the dinoflagellate-mixed groups, while it was not present in the field samples or in the pure I. galbana control, showing that carnosine participated in the anti-stress activities when the clam was exposed to the dinoflagellates. The global composition of FAs did not significantly vary among the groups. However, contents of the endogenous C 18 PUFA precursors linoleic acid and α-linolenic acid significantly decreased in the high-density KV group compared to all the other groups, indicating that high density of KV affected the metabolisms of fatty acids. From the results of the changed VOC composition, oxidation of fatty acids and degradation of free amino acids might occur in the clams exposed to dinoflagellates. The increased VOCs, such as aldehydes, and decreased 1-octen-3-ol probably produced a more fishy taste and reduced food flavor quality when the clam was exposed to the dinoflagellates. This present study demonstrated that the biochemical metabolism and seafood qulity of the clam were affected. However, KZ with moderate density in the feed seemed to be beneficial in aquaculture for increasing the content of carnosine, a high-valued substance with multiple bioactivities. [ABSTRACT FROM AUTHOR]

In the world of cloud technologies, serverless computing has now settled as a stable and promising resident. This gives a cloud provider the flexibility to provide its users with both Platform-as-a-Service (PaaS), i.e., the back-end application runs in a dedicated container, or Function-as-a-Service (FaaS), i.e., the back-end logic is offered as elementary functions that are invoked by the client applications. In parallel, edge computing has attracted a significant interest, due its enticing promises of reducing the outbound traffic of telco operators, while at the same time cutting down the user latency. As a result, in the near future, PaaS and FaaS containers are going to cohabit in a versatile computation infrastructure spanning from the far edge up to the cloud. In this paper we propose a mathematical formulation of a resource allocation problem that optimizes the assignment of both types of containers and can be solved efficiently by an edge orchestrator. We evaluate the proposed solution via extensive simulation experiments, which show that our approach, which takes into account the characteristics of PaaS vs. FaaS, provides significant performance benefits compared to less sophisticated strategies, despite its relatively low run-time complexity. [ABSTRACT FROM AUTHOR]

In the paper an application of solid phase extraction technique for speciation analysis of manganese in water samples with the use of flame atomic absorption spectrometry is presented. Two types of sorbents, activated silica gel and Dowex 1 × 4, were used respectively for simultaneously Mn 2 + and MnO 4 2 − retention and preconcentration. The whole procedure was realized in multicomutation flow system. Different conditions like: type and concentration of eluent, sample pH and loading time were tested during the study. Under appropriate conditions, it was possible to obtained enrichment factors of 20 and 16 for Mn(II) and Mn(VII), respectively. Precision of the procedure was close to 4% (measured as relative standard deviation), whereas the detection limit (3σ) was 1.4 μg·L − 1 for Mn(II) and 4.8 μg·L − 1 for Mn(VII). [ABSTRACT FROM AUTHOR]

A new approach to the analysis of Cu, Fe, Mn and Zn in flaxseed was developed based on infrared-assisted acid digestion. Quantitation by flame atomic absorption spectrometry yields results in agreement with those arising from aggressive total decomposition using conventional microwave-assisted (MW) digestions. A full factorial design in two levels was applied to evaluate the impact of significant variables for all elements to determine optimal experimental conditions. A desirability function revealed these to be: 2.0 g sample mass, 8 mL of HNO 3 and 8 min of heating time in the IR system. Precision better than 10% (RSD) was obtained, superior to that of a combined IR-MW approach. Sample preparation based on IR-assisted digestion provides a rapid and inexpensive alternative to other conventional techniques for the analysis of complex samples and is able to accommodate relatively large masses of sample, alleviating potential homogeneity issues as well as enhancing detection power. [ABSTRACT FROM AUTHOR]

A preconcentration procedure has been developed by using a thiocarbohydrazide derivative (1,5-bis(phenylthiocarbamoyl) thiocarbohydrazide) as a novel sorbent. The ligand was synthesized and used for preconcentration of Cu(II), Ni(II), Pb(II), and Cd(II) ions from water samples by batch and column procedures to enrich metal concentrations appropriate for flame atomic absorption spectrophotometry (FAAS). The optimum pHs for effective solid-phase extractions were 5 and 7 for Cu(II), and Ni(II), Pb(II) and Cd(II) adsorptions, respectively. The method detection limits 0.73, 0.05, 1.14 and 0.04 ng mL-1; the method determination limits 2.4, 0.15, 3.76 and 0.13 ng mL-1 and the enrichment factors 30, 65, 26 and 50 were found for Cu(II), Ni(II), Pb(II) and Cd(II), respectively. The sorption and desorption yields and overall recoveries of metals were almost quantitative except Pb(II) of which sorption yield was around 72% with relative standard deviation value around 1.8%. Langmuir, Freundlich and Temkin models were examined for the metal adsorptions. The Langmuir isotherm model provided a better fit with high correlation coefficients. Regarding the Langmuir parameters, the maximal adsorption capacities on 1,5-bis(phenylthiocarbamoyl) thiocarbohydrazide were 18.25, 7.99, 13.26 and 12.96 mg g-1 for Cu(II), Ni(II), Pb(II) and Cd(II), respectively. The adsorption kinetics for the adsorptions of metals were studied by using linear forms of pseudo-first-order and pseudo-second-order kinetic models. Pseudo-second-order kinetic model fitted very well. The developed method has been successfully applied to the preconcentration of Cu(II), Ni(II), Pb(II) and Cd(II) in water samples (tap water, seawater and mineral water samples), and satisfactory and reproducible results were obtained in FAAS analysis. [ABSTRACT FROM AUTHOR]

This study was performed to develop a sensitive analytical method for the determination of cadmium by slotted quartz tube-flame atomic absorption spectrometry (SQT-FAAS) after dispersive liquid-liquid microextraction (DLLME). The parameters affecting the cadmium complex formation and its extraction output were optimized to obtain high extraction efficiency. These included the pH and amount of the buffer solution, and the concentration of the ligand. The DLLME method was comprehensively optimized based on the type and amount of extraction solvent, dispersive solvent and salt. The type and period of mixing needed for a more effective extraction was also investigated. In order to further improve the sensitivity for the determination of cadmium, the flame atomic absorption spectrometry was fitted with a slotted quartz tube to increase the residence time of cadmium atoms in the pathway of incident light from a hollow cathode lamp. The limits of detection and quantitation (LOD and LOQ) for the FAAS were found to be 42 and 140 μg L − 1 , respectively. Under the optimum conditions, LOD and LOQ of the FAAS after DLLME were calculated as 1.3 and 4.4 μg L − 1 , respectively. Combining both optimized parameters of the DLLME and SQT-FAAS gave 0.5 and 1.5 μg L − 1 as LOD and LOQ, respectively. Accuracy of the method was also checked using a wastewater certified reference material (EU-L-2), and the result was in good agreement with the certified value. [ABSTRACT FROM AUTHOR]

The characterization of inorganic elements in the produced water (PW) samples is a difficult task because of the complexity of the matrix. This work deals with a study of a methodology for dissolved Fe quantification in PW from oil industry by flame atomic absorption spectrometry (FAAS) after cloud point extraction (CPE). The procedure is based on the CPE using PAN as complexing agent and Triton X-114 as surfactant. The best conditions for Fe extraction parameters were studied using a Box-Behnken design. The proposed method presented a LOQ of 0.010 μg mL − 1 and LOD of 0.003 μg mL − 1 . The precision of the method was evaluated in terms of repeatability, obtaining a coefficient of variation of 2.54%. The accuracy of the method was assessed by recovery experiments of Fe spiked that presented recovery of 103.28%. The method was applied with satisfactory performance to determine Fe by FAAS in PW samples. [ABSTRACT FROM AUTHOR]

In this study, a miniaturized liquid-liquid extraction (LLE) method for pre-concentration of Na, K, Ca, and Mg in crude oil was proposed. Analytes in crude oil were quantitatively extracted to the aqueous phase, followed by flame atomic absorption spectrometry (FAAS) determination. The following parameters were evaluated: type of extraction solution, sample mass, heating temperature and time, stirring time, centrifugation time, and the use of toluene and chemical demulsifier. Accuracy was evaluated by comparing the results obtained by the proposed method (LLE-FAAS) with those obtained after high-pressure microwave-assisted wet digestion and FAAS determination (reference values). No statistical difference was observed between the reference values and those using the optimized conditions for LLE-FAAS: 2.5 g of sample; 1000 μL of 2 mol L−1 HNO 3 , 50 mg L−1 of chemical demulsifier in 500 μL of toluene, 10 min of heating at 80 °C, 60 s of stirring, and 10 min of centrifugation. Relative standard deviations were lower than 6%. The limits of quantification (LOQ) were 1.2, 1.5, 5.0, and 0.50 μg g−1 for Na, K, Ca, and Mg, respectively. The proposed miniaturized LLE method presents several advantages, such as ease-of-use, high throughput (up 10 samples can be processed per 1 h), uses a high sample mass reaching low LOQs. In addition, the use of a diluted solution for extraction reduces the amount of reagents (around 40 times) and consequently laboratory residue generation, becoming an environmental friendly method. Suitable LOQs were achieved for analyte determination at low concentration even using a simple and low-cost sample preparation system (miniaturized LLE method) and a relatively low-cost determination technique (FAAS), avoiding the use of microwave ovens and more sensitivity techniques, which are required for routine analyses. [Display omitted] • Miniaturized LLE method was applied for crude oil samples. • Determination of Ca, K, Mg, and Na was performed by FAAS. • Only diluted acid was used as extraction solution. • Suitable LOQs were achieved to analyte determination at low concentration. [ABSTRACT FROM AUTHOR]

An ethylenediamine functionalized glycidyl methacrylate (GMA) based terpolymeric chelating resin was synthesized for the separation and preconcentration of Cd(II) and Zn(II) by SPE from bread, rice and fruit juice prior to FAAS determination. The resin was characterized by FT-IR, TGA/DTA, SEM, BET analysis and EDS. Synthesized resin shows a good capacity of 53.96 mg g −1 for Cd(II) and 24.19 mg g −1 for Zn(II) at pH 8.0. Five isotherm equilibrium models were studied to explain the sorption phenomenon out of which Langmuir, Dubinin–Radushkevich, Scatchard and Temkin models were found to be the best fitted. The limit of detection (LOD) and limit of quantification (LOQ) were observed to be 1.5 and 5.1 μg L −1 for Cd and 1.2 and 4.1 μg L −1 for Zn. The reliability of the method was investigated by the analysis of SRM and the recovery of analytes from various spiked food samples. [ABSTRACT FROM AUTHOR]

This study made use of the unique extraction properties of deep eutectic solvents (DESs) to determine trace levels of cadmium by slotted quartz tube flame atomic absorption spectrometry (SQT-FAAS). Ultrasound assisted (UA)-DES was applied in this study to improve the detection limit. The optimum extraction conditions were 1:2 ratio of choline chloride and phenol as DES, 0.50 mL DES volume, 1.0 mL emulsifier agent volume and 10 s of manual mixing. The linear calibration range of the optimum method was between 1.0 and 50 μg L−1. Combining the DES extraction method and SQT-FAAS gave 0.35 and 1.2 μg L− 1 as the limits of detection and quantitation (LOD and LOQ), respectively. The sensitivity was improved by about 80 folds when compared with the conventional FAAS system. Accuracy and applicability of the method were also checked using celery and apple samples, and the recovery results calculated were close to 100%, respectively. Unlabelled Image • A sensitive and accurate method was developed using a green solvent. • SQT was used in order to enhance the sensitivity of the system. • The method provided 85-fold enhancement when compared to FAAS. [ABSTRACT FROM AUTHOR]

Ag modified ZnO nanoflowers were synthesized by using hydrothermal method and used as dispersive micro-solid phase extractant for separation and preconcentration prior to its flame atomic absorption spectrometric detection. The Ag modified ZnO nanoflowers has been characterized by FT-IR, XRD, FESEM, EDX and BET. The factors effecting extraction efficiency like pH, Adsorbent dose, sample volume, eluent concentration, eluent volume was optimized. Matrix effects were also studied. The limit of detection and preconcentration factor (PF) were calculated as 8.52 μg L−1, and 100, respectively. The presented dispersive micro-solid phase extraction technique was validated using GBW07424 (GSS-10) soil and GBW07425 (GSS-11) soil certificated reference materials (CRMs) with satisfactory recovery results. The presented dispersive micro-solid-phase extraction (d -μSPE) procedure was successfully applied to food and water samples. [Display omitted] • Ag modified ZnO nanoflowers were synthesized by using hydrothermal method. • Ag modified ZnO nanoflowers were used for the solid phase extraction of lead (II). • The limit of detection and preconcentration factor were calculated as 32.7 ng/mL, and 100, respectively. • The method was successfully applied to food and water samples. [ABSTRACT FROM AUTHOR]

In this study, a simple and rapid solid phase extraction/preconcentration procedure was developed for determination of Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Mn(II), Pb(II), and Zn(II) trace metals by flame atomic absorption spectrometry (FAAS). A new chelating resin, poly(N-cyclohexylacrylamide-co-divinylbenzene-co-2-acrylamido-2-methyl-1-propanesulfonic acid) (NCA-co-DVB-co-AMPS) (hereafter CDAP) was synthesized and characterized. The influences of the analytical parameters such as pH of the sample solution, type and concentration of eluent, flow rates of the sample and eluent, volume of the sample and eluent, amount of chelating resin, and interference of ions were examined. The limit of detection (LOD) of analytes were found (3 s) to be in the range of 0.65–1.90 μg L −1 . Preconcentration factor (PF) of 200 and the relative standard deviation (RSD) of ⩽2% were achieved ( n = 11). The developed method was applied for determination of analytes in some dairy samples and certified reference materials. [ABSTRACT FROM AUTHOR]

In this study, we developed a simple and rapid solid phase extraction (SPE) method for the separation/preconcentration and determination of some trace metals by flame atomic absorption spectrometry (FAAS). A new chelating resin, poly [2-(4-methoxyphenylamino)-2-oxoethyl methacrylate-co-divinylbenzene-co-2-acrylamido-2-methyl-1-propanesulfonic acid] (MPAEMA-co-DVB-co-AMPS), was synthesized and characterized. This chelating resin was used as a new adsorbent material for determination of Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Mn(II), Pb(II), and Zn(II) ions. The parameters influential on the determination of this trace metals were examined. Under the optimum conditions, the detection limits (DL) of the method for trace metals were found to be (3 s) in the range of 0.9–2.2 μg L −1 ( n = 21), the preconcentration factor was calculated as 200 and the relative standard deviation was obtained achieved as ⩽2% for n = 11. The method was performed for the determination of trace metals in some honey samples and standard reference materials. [ABSTRACT FROM AUTHOR]

A new nanoporous 1,2-diaminocyclohexane-functionalized SBA-15 (Dach@SBA-15) silica sorbent was prepared. The structure and physicochemical properties of the material were characterized by elemental analysis, X-ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy, FT-IR spectroscopy, nitrogen adsorption–desorption isotherms and thermogravimetric analysis. TEM image clearly showed the sheet-like structure of Dach@SBA-15. The organic functional groups were successfully grafted onto the SBA-15 surface and the ordering of the support was not affected by the chemical modification. The Dach@SBA-15was used as a sorbent for removal of Cu(II) and Ni(II) from aqueous solution. Experimental parameters like effect of pH, contact time and metal ion concentration were studied and optimized. The adsorption isotherm data fitted well to Langmuir isotherm model and the monolayer adsorption capacity values for Cu(II) was 90.09 and for Ni(II) was 84.03 mg/g at 303 K. The experimental kinetic data fitted very well to the pseudo-second-order model. The Dach@SBA-15 could be used as a sorbent for removal of Cu(II) and Ni(II) from aqueous medium. [ABSTRACT FROM PUBLISHER]

The dried biomass ofTrichodermasp. was investigated to remove toxic heavy metal ions using the batch method in the concentration range of 0.5 to 2.0 mg/L at different pH. The biosorption capacity ofTrichodermabiomass was found to be pH dependent. Biosorption of nickel at pH 10 was observed 20% higher than at pH 2. The maximum sorption (91%) for Cd(II) was achieved (0.45 mg cadmium/g biomass) at pH 10 within 72 h equilibrium time. The maximum sorption capacity of Cr(VI) was achieved (0.053 mg chromium/g biomass) upon equilibration after 72 h. In comparison with nickel and cadmium, the biosorption of chromium was found to be pH independent, while nickel and cadmium showed a higher absorption capacity at higher pH. In addition, Freundlich and Langmuir adsorption isotherms were used to verify the biosorption performance ofTrichodermabiomass. Langmuir adsorption isotherm was found to be fit better than Freundlich adsorption isotherm. The dried biomass ofTrichodermahas been fruitfully applied for the removal and recovery of Ni(II), Cd(II), and Cr(VI) ions. Thus, it can be successfully used for the treatment of toxic heavy metal ions from the industrial effluents as well as natural waters. [ABSTRACT FROM AUTHOR]

In utilising metal surfaces that are in constant contact with each other, metal-on-metal (MoM) surgical implants present a unique challenge, in the sense that their necessity is accompanied by the potential risk of wear particle generation, metal ion release and subsequent patient toxicity. This is especially true of orthopaedic devices that are faulty and subject to failure, where the metal surfaces undergo atypical degradation and release even more unwanted byproducts, as was highlighted by the recent recall of orthopaedic surgical implants. The aim of this review is to examine the area of metallosis arising from the wear of MoM articulations in orthopaedic devices, including how the surgical procedures and detection methods have advanced to meet growing performance and analytical needs, respectively. [ABSTRACT FROM AUTHOR]

An ultrasound-assisted extraction procedure was evaluated for the multi-element determination of Cu, Mn, Ca, and Mg in alternative oilseed crops using flame atomic absorption spectrometry. The best results were obtained when 0.3 g of samples were used to extract the mineral content using 10 mL of a 1.40 mol L −1 HNO 3 solution for 10 min at 25 °C. The accuracy and precision of the analysis were evaluated using two oilseed reference materials, and the results were in agreement with reference values at 95% confidence level (paired t- test). The method was used to analyze five oilseed samples and the results were in agreement with those obtained using a closed-vessel microwave-assisted acid digestion system for sample preparation. The relative standard deviations were 0.52–6.13% for all of the standard and sample measurements, and the limits of detection were 666.7, 416.7, 333.4 μg g −1 , and 3.5 mg g −1 for Cu, Mn, Ca, and Mg, respectively. [ABSTRACT FROM AUTHOR]

A simple and fast ultrasound-assisted procedure for the determination of iron and zinc in infant formulas is presented. The analytical determinations were carried out by flame atomic absorption spectrometry. Multivariate experiments were performed for optimization; in addition, a comparative study was carried out using two ultrasonic devices. A method using an ultrasonic bath was selected because several samples can be prepared simultaneously, and there is less contamination risk. Analytical precision (sr(%)) was 3.3% and 4.1% for iron and zinc, respectively. Trueness was assessed using a reference material and by comparison of the results obtained analyzing commercial samples using a reference method. The results were statistically equivalent to the certified values and in good agreement with those obtained using the reference method. The proposed method can be easily implemented in laboratories for routine analysis with the advantage of being rapid and in agreement with green chemistry. [ABSTRACT FROM AUTHOR]

[Display omitted] • Simultaneous extraction and determination of Ni (II) and Zn (II) in food samples. • Minimization of solvents consumption. • Selective extraction based on hydrophobic deep eutectic solvents. • Highly sensitive method at ppb (µg/Kg) level. • Universal sample preparation with easier and faster extraction procedure. A new approach was developed for the simultaneous pre-concentration and determination of Ni (II) and Zn (II) in food samples. This method is based on ultrasound-assisted liquid–liquid micro extraction using hydrophobic deep eutectic solvent (DES) and 1,10-phenanthroline as chelating agent. The effect of several parameters, such as pH, selection and volume of DES, amount of chelating agent, time of sonication and centrifugation, was studied. Under optimized conditions, the developed procedure offered exceptional sensitivity and linearity. The limit of detection was approximately 0.029 µg/Kg and 1.5 µg/Kg for Ni (II) and Zn (II), respectively. The proposed method was applied for the pre-concentration and determination of Ni (II) and Zn (II) in hydrogenated edible oils, fishes, and milk samples. The results of this study were compared with reported methods in the literature revealing its advantages. [ABSTRACT FROM AUTHOR]

• Coprecipitation is an green, easy and rapid methodology for preconcentration-separation of Propineb. • Low sample volume requirements were major advantages of the developed technique. • Propineb was quantitatively recovered in many food samples by this method. • The method was independent of matrix effect. In the presented work, a coprecipitation method was developed for separation–preconcentration, and determination of trace quantities of propineb in vegetable samples. Propineb was coprecipitated by using Al(OH) 3. The zinc contents in complex structure of propineb was determined by flame atomic absorption spectrometry (AAS). The propineb concentration was calculated by using stoichiometric relationship between the zinc and propineb. Several parameters including the amount of aluminum(III) as carrier element and hydroxide concentration and sample volume were examined. The effects of matrix ions were also investigated. The preconcentration factor was calculated as 15. The limit of detection (LOD) value for propineb was calculated as 15.2 μg L-1. The presented coprecipitation procedure was successfully applied to determination of propineb in vegetable samples. [ABSTRACT FROM AUTHOR]

Serverless computing is currently the fastest-growing cloud services segment. The most prominent serverless offering is Function-as-a-Service (FaaS), where users write functions and the cloud automates deployment, maintenance, and scalability. Although FaaS is a good fit for executing stateless functions, it does not adequately support stateful constructs like microservices and scalable, low-latency cloud applications. Recently, there have been multiple attempts to add first-class support for state in FaaS systems, such as Microsoft Orleans, Azure Durable Functions, or Beldi. These approaches execute business code inside stateless functions, handing over their state to an external database. In contrast, approaches such as Apache Flink's StateFun follow a different design: a dataflow system such as Apache Flink handles all state management, messaging, and checkpointing by executing a stateful dataflow graph providing exactly-once state processing guarantees. This design relieves programmers from having to "pollute" their business logic with distributed systems error checking, management, and mitigation. Although programmers can easily develop applications without worrying about messaging and state management, executing transactions across stateful functions remains an open problem. In this paper, we introduce a programming model and implementation for transaction orchestration of stateful serverless functions. Our programming model supports serializable distributed transactions with two-phase commit, as well as eventually consistent workflows with Sagas. We design and implement our programming model on Apache Flink StateFun to leverage Flink's exactly-once processing and state management guarantees. Our experiments show that the approach of building transactional systems on top of dataflow graphs can achieve very high throughput, but with latency overhead due to checkpointing mechanism guaranteeing the exactly-once processing. We compare our approach to Beldi that implements two-phase commit on AWS lambda functions backed by DynamoDB for state management, as well as an implementation of a system that makes use of CockroachDB as its backend. • Dataflow systems can serve as execution engines for cloud applications. • Transactional guarantees can be implemented on stateful functions. • Implementing transaction protocols is very simple under exactly-once processing guarantees. • Further work is required for dataflow systems to reach their full potential as backends for cloud applications. • The performance of transactions on stateful functions is comparable to the one of distributed databases. [ABSTRACT FROM AUTHOR]

A novel magnetic silica sorbent with polyelectrolyte multilayers (PEMs) on its surface was prepared, and the sorbent was used for the magnetic solid phase extraction (MSPE) of trace Cu2+ in drinking water with flame atomic absorption spectrometry (FAAS) as the detector. The experimental parameters for the MSPE procedure, such as the pH, desorption conditions, ultrasonic time and co-existing ions effects, were investigated. The adsorption capacity of the new sorbent was 14.7 mg g-1 for Cu2+. The detection limit of the developed method was 0.23 ng mL-1 for Cu2+ with an enrichment factor of 95.7. The analytical data obtained from the certified reference water and rice samples were in good agreement with the certified values. This method was also successfully applied to the determination of trace Cu2+ in different food samples with satisfactory results. [ABSTRACT FROM AUTHOR]

[Display omitted] • TEA assisted Mg(OH) 2 co-precipitation method was combined with PS-MNP-SPME. • Detection limit for the method was obtained as 0.23 µg kg−1. • Seawater sampled from the coast of West Antarctica was used to verify the accuracy. • Recovery results were ranged from 97 to 106% for samples. Precise and accurate determination of elements in seawater requires efficient analytical approaches that are able to overcome challenges such as high salt content and the very low concentrations of elements. In the present study, the triethylamine (TEA) assisted Mg(OH) 2 co-precipitation method was applied to seawater prior to the preconcentration of cadmium by an optimized polystyrene coated magnetic nanoparticles based dispersive solid phase extraction (PS-MNP-DSPE) method. The enriched analyte was determined by a flame atomic absorption spectrometer, which was fitted with a slotted quartz tube as an absorbance signal booster. The limit of detection (LOD) and limit of quantification (LOQ) values calculated for cadmium under optimum conditions of the PS-MNP-DSPE-SQT-FAAS method were 0.23 and 0.77 µg kg−1, respectively. Seawater sampled from the coast of West Antarctica was used to verify the accuracy and applicability of proposed method, and the recovery results (97 – 106%) obtained were very satisfactory. [ABSTRACT FROM AUTHOR]

A novel adsorbent, 3-phenyl-1-(2-pyridyl)thiourea (PPTU) was synthesized and its adsorption capabilities were studied for Cu(II), Cd(II), Ni(II), Pb(II) and Fe(II) cations in the waters such as tap and polluted seawaters. The kinetics, Langmuir and Freundlich isotherms were discussed related to the adsorptions. The adsorption capacities of PPTU were found 9.4; 12.6; 90.9; 57.1 and 30.4 mg g−1 and preconcentration with PPTU including the FAAS step yielded the LOQ values 0.46; 2.65; 1.12; 2.65 and 1.72 ng mL−1 for Cu(II), Cd(II), Ni(II), Pb(II) and Fe(II), respectively. The adsorbent after the elutions and washings could be reused three times in the next adsorptions. The interferences on the adsorptions arising from the major cations of the seawater and the usability of PPTU for interested metals in the seawater were discussed. The proposed method is simple with highly efficient and green preconcentration procedure for trace analysis of the target metal ions. [Display omitted] • 3-phenyl-1-(2-pyridyl)thiourea (PPTU) is capable of heavy metal adsorption • PPTU is proposed to preconcentrate target metal ions in seawater for FAAS • PPTU is stable against acid/base and EDTA solutions and can be used several times • Adsorption kinetics data are consistent with the pseudo-second-order kinetics [ABSTRACT FROM AUTHOR]

[Display omitted] • Green chemistry approach based on Silver nanomaterial and deep eutectic solvent. • Selective lead extraction from edible oil. • Significant improvement in method performance. • Lead analysis in edible oil at µg/L (ppb) level using a green solvent. This paper presents an application of silver nanoparticles impregnated by Deep Eutectic Solvents (DES) as ultrasonication aided microextraction system for lead (II) determination in edible oils. The paper presents a systematic optimization of method parameters and examples of its application for analysis of real samples. Maximum recovery for lead (II) extraction was obtained for choline chloride and phenol with a 1:2 M ratio. Optimum extraction conditions for 2 g oil sample post-digested solution (10 mL, pH = 2) require 1 mL of Ag-nanoparticles solution (0,1mM) and per each 500 µL of DES and tetrahydrofurane. The limit of detection (LOD) and quantification (LOQ) were 0.28 µg/L and 0.94 µg/L. The developed method covers the entire range of expected levels of lead concentration in oil samples -parts per billion levels to higher ones. This method is many folds faster (only 6.5 min/sample are needed) as well as more sensitive comparing to already reported methods. [ABSTRACT FROM AUTHOR]

A redox speciation and preconcentration study of Cr(III) and Cr(VI) using a flow injection system with dual mini-columns prepared from cross-linked polymers-poly(methacrylic acid) and polyvinylimidazole was developed. Characterization of organic polymers was performed by using FTIR, SEM, TG, C:H:N and BET measurements. The equilibrium data obtained from Cr(III) adsorption on poly(methacrylic acid) and Cr(VI) on polyvinylimidazole were fitted very well to the dual site Langmuir-Freundlich model, suggesting the presence homogeneous and heterogeneous binding site and providing maximum adsorption capacities of 1.42 and 3.24 mg g-1, respectively. The adsorption kinetics data were described by the pseudo-second-order model for both polymers, thus corroborating to isotherm data. The on-line preconcentration/speciation system was operated by loading 18.0 mL of a solution containing Cr(III) and Cr(VI) at pH 4.0 through the dual mini-columns at a flow rate of 3.0 mL min-1, where Cr(III) was selectively retained on poly(methacrylic acid), while Cr(VI) was retained on polyvinylimidazole. The limits of detection were found to be 0.84 and 1.58 μg L-1 for Cr(III) and Cr(VI), respectively. The preconcentration factor (PF), consumptive index (CI) and concentration efficiency (CE) were found to be 47.3/8.6, 0.38/2.1 mL and 7.88/1.43 min-1 for Cr(III) and Cr(VI), respectively. The developed method was successfully applied to the speciation of chromium in different kinds of water samples. Satisfactory recovery values ranging from 89.9 to 108.3% were obtained. [ABSTRACT FROM AUTHOR]

Abstract: An on-line nickel preconcentration and determination system implemented with flame atomic absorption spectrometry (FAAS) was developed. The nickel was retained on the inner walls of a column filled with ethyl vinyl acetate (EVA). The EVA was used as sorbent material for on-line solid-phase extraction (SPE) in the absence of complexing agent. The effects of sampling volume, elution conditions, sample pH and flow rate on the Ni extraction were studied. The analytical efficiency parameters obtained with this methodology were: enrichment factor (EF) of 46 times for a preconcentration time of 120s, the limit of detection (LOD) was 3.78μgL−1, and the precision for six replicate determinations (repeatability conditions) at 20μgL−1 Ni concentration was 4.38% relative standard deviation. The sampling frequency for the proposed system was about 20samples/h. The optimized procedure was applied to the determination of Ni in natural water and lake sediment samples. [Copyright &y& Elsevier]

Highlights: [•] Determination of Zn by FI-FAAS in edible oils was developed after EIEB procedure. [•] Emulsions were prepared by mixing edible oil samples with an acidic Triton X-114. [•] Emulsion brought by heating. [•] The proposed procedure was a simple, sensitive, reproducible, and economical. [•] It permitted the use of stable inorganic standards for calibration. [Copyright &y& Elsevier]

Highlights: [•] Novel and stable magnetically driven silica based nanoadsorbent. [•] Highly efficient for selective recovery of cadmium from environmental samples. [•] Equilibrium, kinetic and thermodynamic parameters were investigated. [•] Facile separation using external magnet. [•] High reusability with good adsorption performance for eight consecutive cycles. [ABSTRACT FROM AUTHOR]

Highlights: [•] A new material (SiO2/Nb2O5/ZnO) was prepared. [•] The life time of adsorbent was very high. [•] A preconcentration factor of 26times was achieved. [•] The method provides low limit of detection and low sample consumption. [ABSTRACT FROM AUTHOR]

Highlights: [•] Dispersive liquid–liquid microextraction is rapid and sensitive method for copper. [•] The concentration of copper in cereals and vegetables is determined using FAAS. [•] 200μL volume of organic solvent is used to separate and preconcentrate copper. [•] Linearity range is 0.2–20ng/mL copper with correlation of estimation of 0.996. [•] The present method is found sensitive and selective compared to other methods. [Copyright &y& Elsevier]

A study on speciation of chromium in soils near Sheba Leather Industry was performed by Flame Atomic Absorption (FAAS) after selective extraction of Cr(VI) using the EPA 3060A method, and oxidizing the Cr(III) residue in the soils with HNO3 and H2O2. The extraction method was evaluated using the spiking method with satisfactory results (recoveries>95% and RSDs<5%). The limit of detection (LOD) for Cr(VI) based on three times the standard deviations of the blank (for n=5) was 0.56µgg−1. Statistical evaluation indicated that the comparison of the sum of the concentrations of chromium species to that of the total concentration of chromium do not show any difference at 95% level of confidence. Besides, no statistically significant difference at 95% confidence level was observed between the UV–vis spectrophotometry and FAAS results for Cr(VI). However, it is observed that selective extraction of Cr(VI) using EPA 3060A and subsequent determination by FAAS is simple and faster compared to the other method. Furthermore, for comparison and as control two soil samples collected from a distance of about 2km from the main Industry and effluent stream. The results indicate that higher total chromium content was observed in soils collected from the target area. Nevertheless, the maximum concentrations of Cr(VI) found in soil samples collected around Sheba Leather Industry was 9.9µgg−1 and are within the acceptable level of 10µgg−1 in accordance with the WHO. [ABSTRACT FROM AUTHOR]

Abstract: Brazilwood was used in this work to dye wool mordanted with different amounts of copper(II) sulfate, alum and iron(II) sulfate. Two different dyeing methods were used: premordanting (MD) and simultaneous mordanting (M+D) procedures. In order to evaluate the influence of the mordant ion in the brazilein chromophore photodegradation, samples were subjected to artificial light ageing. Color measurements were made and, for the first time, LC-DAD-ESI-MS was used for chromophore analysis of the dyed fibers before and after light exposure. Mordant ion quantification was done after fiber acid digestion, by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and flame atomic absorption spectroscopy (FAAS). Mordant metal ion, mordant bath concentration and dyeing procedure were found to have strong influence in the wool fiber hues. Color variation was more pronounced in the alum dyed samples. Overall, mordant quantification showed that the amount of metal ions found in the fibers is very small when compared to the original concentrations of the dyeing bath, being Cu the ion with greater affinity for the wool fibers. MD dyeing procedure yielded fibers with larger amounts of mordant metal ions and higher chromophore peak areas. Higher amounts of brazilein were extracted from wool mordanted with copper(II) sulfate. Finally, chromatographic analysis of the brazilwood dyed samples before and after light exposure resulted in the detection of Type C compound as an outcome of the photodegradation process. [Copyright &y& Elsevier]