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A novel CuS grafted PEDOT:PSS conducting paper-based electrochemical immunosensor has been successfully fabricated for the detection of EpCAM antigen. Electrical conductivity is further improved by doping the CuS@PEDOT:PSS/WP electrode with different organic solvents such as N,N-dimethyl formamide (DMF), N,N-dimethyl acetamide (DMA), ethylene glycol (EG) and dimetyl sulfoxide (DMSO). It is observed that DMSO doped conducting paper shows the highest conductivity (6.1 × 10−2 S/cm) among all these solvents. This low cost, biodegradable electrochemical paper-based immunosensor (BSA/anti-EpCAM/EP) possesses a broad linear range from 0.01 pg/mL to 1000 ng/mL for EpCAM antigen detection. The immunosensor is found to have high sensitivity of 104.31 μA pg−1 mL. This conducting paper based immunosensor is further used to detect EpCAM antigen in human serum samples, thereby confirming a cost effective clinical tool over other costly conventional techniques. • An electrochemical paper-based immunosensor has been designed using CuS and PEDOT:PSS. • This low cost and flexible platform may be a promising candidate over other costly conventional electrodes. • It exhibits high sensitivity of 104.31 μA pg−1 mL in broad range of 0.01 pg/mL to 1000 ng/mL, for EpCAM detection. • The clinical applicability and validity has been checked with human serum sample. [ABSTRACT FROM AUTHOR]

One of the major components of the organic solvent extractable fraction of Cretaceous ambers is 1,6-dimethyl-5-isopentyltetralin, a compound that has been incorrectly or not identified in previous reports on the molecular composition of Cretaceous ambers. Here, the purification and structural identification of 1,6-dimethyl-5-isopentyltetralin is reported from amber samples of the Cretaceous Peñacerrada II deposit at Peñacerrada, Álava (Basque-Cantabrian Basin, Spain). The structural identification of 1,6-dimethyl-5-isopentyltetralin allowed the complete identification of related compounds, comprising the family of 1,6-dimethyl-5-alkyltetralins. This suggests that those compounds, with concentrations up to 27% of the total organic extract of amber from Peñacerrada, are characteristic for labdane-type biomarkers in Cretaceous fossil resins and their distributions indicate different compositional families, related to their botanical and topographic origin. Also, the name amberene is proposed for the main molecule of this group. The relative proportion of the amberene-type compounds suggests three compositional families for the Cretaceous Spanish ambers. [ABSTRACT FROM AUTHOR]

N -alkyl-2-pyrrolidones are important organic solvents for varnishes in industry. This study investigates exposure to N -ethyl-2-pyrrolidone (NEP) in varnishing of hard plastic components in an automobile plant. Two specific biomarkers of exposure, 5-hydroxy- N -ethyl-2-pyrrolidone (5-HNEP) and 2-hydroxy- N -ethylsuccinimide (2-HESI), were analyzed in urine samples of 14 workers. For this purpose, pre-shift, post-shift and next day pre-shift urine samples were collected midweek. Twelve workers performed regular work tasks (loading, wiping and packing), whereas two workers performed special work tasks including cleaning the sprayer system with organic solvents containing N -alkyl-2-pyrrolidones. Spot urine samples of nine non-exposed persons of the same plant served as controls. Median post-shift urinary levels of workers with regular work tasks (5-HNEP: 0.15 mg/L; 2-HESI: 0.19 mg/L) were ∼5-fold higher compared to the controls (0.03 mg/L each). Continuously increasing metabolite levels, from pre-shift via post-shift to pre-shift samples of the following day, were observed in particular for the two workers with the special working tasks. Maximum levels were 31.01 mg/L (5-HNEP) and 8.45 mg/L (2-HESI). No clear trend was evident for workers with regular working tasks. In summary, we were able to show that workers can be exposed to NEP during varnishing tasks in the automobile industry. [ABSTRACT FROM AUTHOR]

The first step in many life detection protocols on Mars involves attempts to extract or isolate organic matter from its mineral matrix. A number of extraction options are available and include heat and solvent assisted methods. Recent operations on Mars indicate that heating samples can cause the loss or obfuscation of organic signals from target materials, raising the importance of solvent-based systems for future missions. Several solvent types are available (e.g. organic solvents, surfactant based solvents and subcritical water extraction) but a comparison of their efficiencies in Mars relevant materials is missing. We have spiked the well characterised Mars analogue material JSC Mars-1 with a number of representative organic standards. Extraction of the spiked JSC Mars-1 with the three solvent methods provides insights into the relative efficiency of these methods and indicates how they may be used on future Mars missions. [ABSTRACT FROM AUTHOR]

Highlights: [•] New accelerated solvent extraction use for cocaine analytes isolation in meconium samples. [•] Fully validated method for cocaine fetal exposure confirmation, with proper sensibility. [•] Minor sample handling, smaller demand of organic solvents, faster and accurate procedure. [•] Successful method application in meconium samples from University Hospital, Brazil. [ABSTRACT FROM AUTHOR]

Highlights: [•] Acetone (20μll−1) accelerates embryonic development in Potamopyrgus antipodarum. [•] Ethanol (20μll−1) decreases growth in juvenile mudsnails. [•] Acetone, ethanol, methanol and DMSO increase E2 levels in snails. [•] Carrier solvents impair gene expression. [•] DMSO is to be preferred. [Copyright &y& Elsevier]

Abstract: Multiplexed electrochemical immunosensor was developed for ultrasensitive detection of interleukin-6 (IL-6) and interleukin-17 (IL-17) using electrochemical tag incorporated polystyrene sphere (PS) as label. The electrochemical tag contained in the PS, cadmium ion (Cd2+) or ferrocene (Fc), could be effectively detected by square wave voltammetry (SWV) after dissolving the PS with organic solvent to release the electrochemical tags onto electrode surface. With the immobilization of two different antibodies onto the PS surface, respectively, the position and intensity of the current peaks due to the two electrochemical tags could reflect the identity and level of the corresponding protein biomarkers. The significant amount of electrochemical tags incorporated into PS greatly enhanced the detection sensitivity. The proposed immunoassay exhibited high sensitivity and good selectivity for the detection of IL-6 and IL-17. The response current was linear to the logarithm concentrations of IL-6 and IL-17 in the range from 1pg/mL to1ng/mL and 2pg/mL to 1ng/mL, respectively. The detection limits of IL-6 and IL-17 were 0.5 and 1pg/mL (S/N=3). These results suggested that this electrochemical immunosensor would be widely applied for clinical screening of protein biomarkers. [Copyright &y& Elsevier]

Abstract: Hydrophilic-interaction liquid chromatography (HILIC) is a widely used technique for small polar molecule analysis and offers the advantage of improved sensitivity in mass spectrometry. Although HILIC is today frequently employed as an orthogonal fractionation method for peptides during the proteomic discovery phase, it is still seldom considered for quantification. In this study, the performances in terms of peak capacity and sensitivity of 3 HILIC columns were compared to traditional reversed phase liquid C18 column in the context of targeted quantification of proteotypic peptides using selected reaction monitoring mode (SRM). The results showed that the maximum sensitivity in HILIC chromatography was achieved by using an amide column without salt buffer and that the signal increased compared to classic reversed phase chromatography. However, the intensity improvement is quite low compared to the one obtained for small molecules. This is due on one hand to a higher matrix effect in HILIC and on the other hand to a change of charge states of peptides in organic solvent (doubly charged to monocharged). The doubly charged ions can be more readily dissociated than singly charged ions, making them ideal for SRM peptide quantification. As a result “supercharging” reagents are added to the mobile phase to shift from predominant singly charged ions to the more favorable doubly charged species. Using such optimized conditions, peptide signal is improved by a factor of between two and ten for 88% of the peptides of the 81 peptides investigated. [Copyright &y& Elsevier]

Abstract: We report the original design of a new type of electronic nose (e-nose) consisting of only five sensors made of hierarchically structured conductive polymer nanocomposites (CPC). Each sensor benefits from both the exceptional electrical properties of carbon nanotubes (CNT) used to build the conductive architecture and the spray layer by layer (sLbL) assembly technique, which provides the transducers with a highly specific 3D surface structure. Excellent sensitivity and selectivity were obtained by optimizing the amount of CNT with five different polymer matrices: poly(caprolactone) (PCL), poly(lactic acid) (PLA), poly(carbonate) (PC), poly(methyl methacrylate) (PMMA) and a biobased polyester (BPR). The ability of the resulting e-nose to detect nine organic solvent vapours (isopropanol, tetrahydrofuran, dichloromethane, n-heptane, cyclohexane, methanol, ethanol, water and toluene), as well as biomarkers for lung cancer detection in breath analysis, has been demonstrated. Principal component analysis (PCA) proved to be an excellent pattern recognition tool to separate vapour clusters. [Copyright &y& Elsevier]

Abstract: 2′-Deoxyguanosine (dG) suffers from oxidation by reactive oxygen species (ROS) to form 8-oxo-2′-deoxyguanosine (8-oxo-dG), which is regarded as a marker of oxidative stress in the cells. In our continuous study for the recognition molecule of 8-oxo-dG, 8-oxoGclamp and its derivatives have been identified as the selective fluorescent probe. However, it is an obstacle for further application that dG also forms a complex with 8-oxoGclamp, resulting in fluorescence quenching in less polar solvents. Quenching of the fluorescence of 8-oxoGclamp is thought to involve photo-induced electron transfer in the complex. It was hypothesized that the energy level of the excited state of 8-oxoGclamp and the HOMO energy of dG are the preliminary determinant of the quenching efficiency. Thus, fluorescence properties of the substituted derivatives at the 7-position of the 1,3-diazaphenoxazine part of 8-oxoGclamp were investigated. Among the new derivatives, fluorescence of the 7-phenyl substituted 8-oxoGclamp was not quenched by dG even in the stable complex, exhibiting the highest selectivity for 8-oxo-dG. [Copyright &y& Elsevier]

Abstract: Organic solvent abuse typically involves sniffing organic solvents to experience the mind-altering conditions they induce. In Republic of Korea, organic solvent abuse is a serious social problem, especially among teenagers. Several studies have addressed the effects of organic solvent abuse on mind and body, but there are no simple methods by which such abuse can be positively identified. In this report, we describe a method for analyzing toluene metabolites (toluene is the main ingredient of glue) in glue-sniffers’ urine using 1H NMR spectroscopy. Toluene is a commonly used solvent in the rubber, paint, plastics, leather, printing, and chemical industries. Inhaled toluene is metabolized to hippuric acid in the liver and excreted in the urine. Hippuric acid is known as a good biomarker for biological monitoring of toluene exposure. We have scanned hippuric acid and other toluene metabolites by NMR spectroscopy and performed statistical multivariate analysis of the data. Based on this analysis, we sought to determine parameters by which glue-sniffing (toluene inhalation) behavior may be verified. We also demonstrate the use of a pattern recognition method for accurate and efficient analysis of NMR data. In comparison to conventional methods, such as mass spectroscopy coupled with liquid chromatography or gas chromatography, nuclear magnetic resonance spectroscopy has several advantages, including simple sample preparation, non-destructive sampling, accuracy, short acquisition time, and reproducibility in the determination of urinary hippuric acid. [Copyright &y& Elsevier]

Abstract: The aim of the study was to quantify the variability on biological indicators of exposure between men and women for three well known solvents: methyl ethyl ketone, 1-methoxy-2-propanol and 1,1,1-trichloroethane. Another purpose was to explore the effect of selected CYP2E1 polymorphisms on the toxicokinetic profile. Controlled human exposures were carried out in a 12m3 exposure chamber for each solvent separately, during 6h and at half of the threshold limit value. The human volunteers groups were composed of ten young men and fifteen young women, including ten women using hormonal contraceptive. An analysis of variance mainly showed an effect on the urinary levels of several biomarkers of exposure among women due to the use of hormonal contraceptive, with an increase of more than 50% in metabolites concentrations and a decrease of up to 50% in unchanged substances concentrations, suggesting an increase in their metabolism rate. The results also showed a difference due to the genotype CYP2E1*6, when exposed to methyl ethyl ketone, with a tendency to increase CYP2E1 activity when volunteers were carriers of the mutant allele. Our study suggests that not only physiological differences between men and women but also differences due to sex hormones levels can have an impact on urinary concentrations of several biomarkers of exposure. The observed variability due to sex among biological exposure indices can lead to misinterpretation of biomonitoring results. This aspect should have its place in the approaches for setting limits of occupational exposure. [Copyright &y& Elsevier]

Abstract: The quantitative multimolecular approach (QMA) based on an exhaustive identification and quantification of molecules from the extractable organic matter (EOM) has been recently developed in order to investigate organic contamination in sediments by a more complete method than the restrictive quantification of target contaminants. Such an approach allows (i) the comparison between natural and anthropogenic inputs, (ii) between modern and fossil organic matter and (iii) the differentiation between several anthropogenic sources. However QMA is based on the quantification of molecules recovered by organic solvent and then analyzed by gas chromatography–mass spectrometry, which represent a small fraction of sedimentary organic matter (SOM). In order to extend the conclusions of QMA to SOM, radiocarbon analyses have been performed on organic extracts and decarbonated sediments. This analysis allows (i) the differentiation between modern biomass (contemporary 14C) and fossil organic matter (14C-free) and (ii) the calculation of the modern carbon percentage (PMC). At the confluence between Fensch and Moselle Rivers, a catchment highly contaminated by both industrial activities and urbanization, PMC values in decarbonated sediments are well correlated with the percentage of natural molecular markers determined by QMA. It highlights that, for this type of contamination by fossil organic matter inputs, the conclusions of QMA can be scaled up to SOM. QMA is an efficient environmental diagnostic tool that leads to a more realistic quantification of fossil organic matter in sediments. [Copyright &y& Elsevier]

Abstract: The life marker chip (LMC) is being designed to test for the chemical signature of life in the soil and rocks of Mars. It will use an antibody array as part of its detection and characterisation system and aims to detect both polar and non-polar molecules at the sub-ppm to tens of ppb level. It is necessary to use a solvent to transfer organic compounds from the Martian samples to the LMC itself, but organic solvents such as dichloromethane or hexane, commonly used to dissolve non-polar molecules, are incompatible with the LMC antibodies. Hence, an aqueous-based solvent capable of dissolving the biomarkers that might exist in the soil or rocks of Mars is required. Solvent extractions of a Martian soil analogue, JSC Mars-1, spiked with a range of standards show that a 20:80 (vol:vol) mixture of methanol and water is incapable of extracting compounds insoluble in water. However, addition of 1.5mgml−1 of the surfactant polysorbate 80 produces extraction efficiencies of the aliphatic standards, hexadecane and phytane, equal to 25–30% of those produced by the common organic solvent mixture 93:7 (vol:vol) dichloromethane:methanol. Extraction of squalene and stigmasterol using the polysorbate solution is less efficient but still successful, at 5–10% of the efficiency of 93:7 dichloromethane:methanol. Such aliphatic compounds with occasional functional groups represent the compound classes to which most fossil organic biomarkers belong. The polysorbate solution did not extract the aromatic compounds pyrene and anthracene with great efficiency. A solvent of 20:80 methanol:water with 1.5mgml−1 polysorbate 80 is therefore capable of selectively extracting aliphatic biomarkers from Martian samples and transferring them to the antibody sites on the life marker chip. [ABSTRACT FROM AUTHOR]

Abstract: Dispersive liquid–liquid microextraction (DLLME) and liquid chromatography–electrospray-tandem mass spectrometry (LC–ES-MS/MS) procedure was presented for the extraction and determination of 7-aminoflunitrazepam (7-aminoFM2), a biomarker of the hypnotic flunitrazepam (FM2) in urine sample. The method was based on the formation of tiny droplets of an organic extractant in the sample solution using water-immiscible organic solvent [dichloromethane (DCM), an extractant] dissolved in water-miscible organic dispersive solvent [isopropyl alcohol (IPA)]. First, 7-aminoFM2 from basified urine sample was extracted into the dispersed DCM droplets. The extracting organic phase was separated by centrifuging and the sedimented phase was transferred into a 300μl vial insert and evaporated to dryness. The residue was reconstituted in 30μl mobile phase (20:80, acetonitrile:water). An aliquot of 20μl as injected into LC–ES-MS/MS. Various parameters affecting the extraction efficiency (type and volume of extraction and dispersive solvent, effect of alkali and salt) were evaluated. Under optimum conditions, precision, linearity (correlation coefficient, r 2 =0.988 over the concentration range of 0.05–2.5ng/ml), detection limit (0.025ng/ml) and enrichment factor (20) had been obtained. To our knowledge, DLLME was applied to urine sample for the first time. [Copyright &y& Elsevier]

Abstract: Hair nicotine is a known biomarker for monitoring long-term environmental tobacco smoke (ETS) exposure and smoking status. In general, hair nicotine assay involves alkaline digestion, extraction and instrumental analysis. The gas chromatography–mass spectrometry (GC–MS) assay currently developed has shown to be of high throughput with average ∼100 hair samples being extracted and analyzed per day. This was achieved through simplified extraction procedure and shortened GC analysis time. The extraction was improved by using small volume (0.4mL) of organic solvent that does not require further evaporation and salting steps prior to GC–MS analysis. Furthermore, the amount of hair utilized in the extraction was very little (5mg) while the sensitivity and selectivity of the assay is equal, if not better than other established methods. The linearity of the assay (r 2 >0.995), limit of quantitation (0.04ng/mg hair), within- and between-assays accuracies and precisions (<11.4%) and mean recovery (92.6%) were within the acceptable range. [Copyright &y& Elsevier]

Abstract: Employees in the footwear manufacturing industry are routinely exposed to complex mixtures of solvents used in cleaning and as diluents in glues, primers, and degreasers. The objective of this study was to determine the genotoxic effects in a group of footwear-workers occupationally exposed to solvent-based adhesive and solutions containing organic solvents, mainly toluene. Peripheral blood and buccal cells samples were collected from 39 footwear-workers (31 males and 8 females) and 55 controls (44 males and 11 females). As biomarker of exposure, we obtained data on hippuric acid (HA), the main metabolite of toluene in urine, and DNA damage detected by the Comet assay in blood cells. Micronucleus frequencies in binucleated lymphocytes (BNMN) and in epithelial buccal cells (EBCMN) were analyzed as biomarkers of effect, while polymorphisms in genes GSTT1, GSTM1, GSTP1, CYP1A1, and CYP2E1 were used as susceptibility biomarkers. Results of HA and Comet assay showed statistical increased values amongst footwear-workers relative to controls (P ≤0.001). No differences were observed in BNMN and EBCMN frequencies between the groups, but a correlation test revealed that age was significantly associated with BNMN frequency in both control (r s =0.290; P ≤0.05) and exposed groups (r s =0.674; P ≤0.001). Regarding the results on genetic polymorphisms, GSTM1 null subjects from the control group showed a significant increase in EBCMN frequency relative to GSTM1 non-null subjects (P ≤0.05). A significant increase in DNA damage detected by Comet assay in leukocytes was obtained for GSTP1 Ile/Val or Val/Val individuals from the exposed group relative to those with GSTP1 Ile/Ile (P ≤0.05), especially in younger subjects (P ≤0.01), and a suggestion of interaction with CYP2E1 polymorphism was found. In confirmation of these data, stepwise multiple regression analyses for selecting between the different independent variables showed that about 25% of levels of the DNA damage in footwear-worker can be associated with genetic polymorphisms in GSTP1 and CYP2E1 (P =0.006, F =5.876). [Copyright &y& Elsevier]

Most bioanalytical LC-MS/MS methods are developed for determination of single drugs or classes of drugs, but a multi-compound LC-MS/MS method that can replace several methods could reduce both analysis time and costs. The aim of this study was to develop a high-throughput LC-MS/MS method for determination of the alcohol biomarker phosphatidylethanol 16:0/18:1 (PEth 16:0/18:1) and 33 other compounds from eight different drug classes in whole blood. Whole-blood samples were prepared by 96-well supported liquid extraction (SLE). Chromatographic separations were performed on a biphenyl core shell column with a mobile phase consisting of 10 mM ammonium formate, pH 3.1 and methanol. Each extract was analyzed twice by LC-MS/MS, injecting 0.4 μL and 2 μL, in order to obtain narrow and symmetrical peaks and good sensitivity for all compounds. Stable isotope-labeled internal standards were used for 31 of the 34 compounds. A 96-well SLE reversed phase LC-MS/MS method for determination of PEth 16:0/18:1 and 33 other compounds from eight different drug classes was developed and validated. By using an organic solvent mixture of isopropanol/ methyl tert-butyl ether (1:5, v:v), all compounds, including the polar and ampholytic compounds pregabalin, gabapentin and benzoylecgonine, was extracted by 96-well SLE. For the first time an LC-MS/MS method for the determination of alcohol biomarker PEth 16:0/18:1 and drugs and metabolites from several different drug classes was developed and validated. The developed LC-MS/MS method can be used for high-throughput analyses and sensitive determinations of the 34 compounds in whole blood. • Quantification of alcohol biomarker PEth 16:0/18:1 and 33 other compounds by LC-MS/MS • First method for quantification of PEth and drugs from several drug classes • Acidic, basic and ampholytic compounds determined by LC-MS/MS • First supported liquid extraction of pregabalin and gabapentin from blood • High throughput sample preparation by 96-well supported liquid extraction [ABSTRACT FROM AUTHOR]

• Determination of occupational exposure of VOC in the University community. • Development and validation of bioanalytical method for simultaneous exposure solvents. • Biological evaluation as tool for assessing occupational exposure. Occupational exposure to volatile organic compounds (VOC) might generate serious worker health damages. Therefore, biological monitoring is essential to evaluate exposure biomarkers from highly toxic chemicals, ensuring better attention to the worker health. In this study was developed and validated a bioanalytical method based on high-performance liquid chromatography coupled to photodiode array (HPLC-PDA) for the quantification of VOC biomarkers in urine samples from Federal University of Goias (UFG) workers. Samples were collected from 30 occupationally exposed subjects after application of a questionnaire survey. The following biomarkers hippuric acid, methyl-hippuric acid, mandelic acid, phenylglyoxylic acid and phenol were quantified, representing exposition to toluene, xylene, styrene, ethylbenzene, benzene and phenol solvents, respectively. Hippuric acid levels were found close to or above the reference values, although a subject had levels higher than preconized by Biological Limit Values (BLV) guideline of 4.0 mg/g creatinine. Five subjects had 3 and 4-methylhippuric acid ranging from 0.1 to 1.0 mg/g creatinine. These results indicate a moderate to high VOC exposure from UFG workers. Multivariate analysis generated four clusters and indicated that histotechnicians and graphic workers need especial attention on occupational VOC exposure. The results from this study reinforce the need for reliable methods able to the biological monitoring as an important tool for assessing occupational exposure. [ABSTRACT FROM AUTHOR]