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VX, a well-known organophosphorus nerve agent (OPNA), poses a significant threat to public safety if employed by terrorists. Obtaining complete metabolites is critical to unequivocally confirm its alleged use/exposure and elucidate its whole-molecular metabolism. However, the nitrogenous VX metabolites containing 2-diisopropylaminoethyl moiety from urinary excretion remain unknown. Therefore, this study applied a newly developed untargeted workflow platform to discover and identify them using VX-exposed guinea pigs as animal models. 2-(N,N -diisopropylamino)ethanesulfonic acid (DiPSA) was revealed as a novel nitrogenous VX metabolite in urine, and 2-(Diisopropylaminoethyl) methyl sulfide (DAEMS) was confirmed as another in plasma, indicating that VX metabolism differed between urine and plasma. It is the first report of a nitrogenous VX metabolite in urine and a complete elucidation of the VX metabolic pathway. DiPSA was evaluated as an excellent VX exposure biomarker. The whole-molecule VX metabolism in urine was characterized entirely for the first time via the simultaneous quantification of DiPSA and two known P-based biomarkers. About 52.1% and 32.4% of VX were excreted in urine as P-based and nitrogenous biomarkers within 24 h. These findings provide valuable insights into the unambiguous detection of OPNA exposure/intoxication and human and environmental exposure risk assessment. [Display omitted] • A novel nitrogenous VX metabolite (DiPSA) was revealed in urine. • DiPSA was evaluated as an excellent biomarker of VX exposure for the first time. • First characterization of whole-molecule VX metabolism in urine. • 32.4% of VX excreted as DiPSA and 52.1% as P-based metabolites in urine within 24 h. • First realizing unique confirmation of whole-molecule VX exposure from urine samples. [ABSTRACT FROM AUTHOR]

• Oral dose of di- n -butyl adipate (DnBA) to three volunteers. • Dose recoveries of four oxidized monoester metabolites 0.005−0.47 % (mean values). • Dermal application of sunscreen containing DnBA (n = 3): different metabolite ratios. • Excretion kinetics up to 48 h (oral) and 72 h (dermal). • Simple monoester and 3-hydroxy metabolite seem specific biomarkers of exposure. Di- n -butyl adipate (DnBA) is used as a plasticizer and in various consumer products (e.g. personal care products) replacing, in part, the endocrine disruptor di- n -butyl phthalate (DnBP). We provide quantitative in vivo data on human DnBA metabolism and excretion after oral dose (105−185 μg/kg bw) and dermal application to three volunteers each as a tool for exposure and risk assessment. Complete and consecutive urine samples were collected for two (oral) and four days (dermal), respectively, and analyzed for the metabolites mono- n -butyl adipate (MnBA), 3- and tentative 4-hydroxy-mono- n -butyl adipate (3OH-MnBA, 4OH-MnBA), and 3-carboxy-mono- n -propyl adipate (3cx-MnPrA), as well as the hydrolysis product adipic acid (AA) using stable isotope dilution quantification. Metabolites were excreted within 24 h after oral dose with one or two concentration maxima at 0.8–3.0 h (n = 3) and 4.8−6.3 h (n = 2). AA was the major but unspecific metabolite with urinary excretion fractions (F UE s) of 14−26 %. Mean F UE s (range) of 3cx-MnPrA, MnBA, 3OH-MnBA, and tentative 4OH-MnBA were low, but consistent between volunteers (0.47 % (0.35−0.63 %), 0.079 % (0.065−0.091 %), 0.012 % (0.006−0.016 %), and 0.005 % (0.002−0.009 %), respectively). MnBA and 3OH-MnBA seem to be suitable, specific exposure biomarkers for DnBA, whereas 3cx-MnPrA and 4OH-MnBA seem to originate also from other, unknown sources not related to DnBA. Compared to the oral study, metabolite excretion in the dermal study was delayed and MnBA excretion was somewhat higher compared to the oxidized metabolites. Based on urinary concentrations and the above excretion fractions, calculated uptakes in the dermal study did not exceed the adipate ester ADI of 5 mg/(kg bw*day). [ABSTRACT FROM AUTHOR]

Aflatoxin M 1 (AFM 1) is generally used as a biomarker in urine for the assessment of aflatoxin exposure in humans and animals. However, there is no approach for the rapid and on-site monitoring of AFM 1 level in urine. Here, we report a surface enhanced Raman scattering (SERS)-based lateral flow immunosensor built for such a purpose. Raman molecule 5,5-dithiobis-2-nitrobenzoic acid and anti-AFM 1 monoclonal antibody were conjugated with Au (core)@Ag (shell) nanoparticle to serve as SERS nanoprobe. AFM 1 -bovine serum albumin was conjugated with gold nanoparticle and then applied onto nitrocellulose membrane as a visible "GOLD" test line. Quantitation of AFM 1 was performed by the readout of Raman signal from the SERS nanoprobes captured on the test line. After optimizing experimental parameters, the detection limit of this immunosensor can achieve as low as 1.7 pg/mL of AFM 1 in urine, which is far below the recommended tolerable level (30 pg/mL) of AFM 1 in urine. The spiking experiment yielded 93.8%–111.3% recovery with coefficients of variation below 17% demonstrating high assay accuracy and precision. Moreover, this immunosensing assay is fast with an assay time below 20 min. Therefore, the developed immunosensor is a promising tool for the rapid assessment of aflatoxin exposure in the field. Image 1 • A surface enhanced Raman scattering-based lateral flow immunosensor was developed for AFM 1 in urine. • A visible "GOLD" test line was constructed to help the accurate location of test line in the immunosensor. • The detection limit was as low as 1.7 pg/mL of AFM 1 in urine. • The spiked recovery ratios were 93.8%–111.3% with coefficients of variation below 17%. • The detection time was less than 20 min. [ABSTRACT FROM AUTHOR]

[Display omitted] • Simultaneous determination of selected pesticides and metabolites in human urine. • UHPLC/QTOFMS coupling perfectly adapted to targeted quantitative analysis. • Deconjugation step essential to measure the total concentration of certain substances. • Likely impact of the thawing/freezing cycles on the stability of certain substances. • Presence of pesticides in their metabolized form in French pregnant women's urine. An innovative method for the determination of pesticides of different uses and from different chemical families and/or their known metabolites in human urine was developed. The protocol includes an enzymatic hydrolysis followed by an off-line solid phase extraction (SPE) step and then a targeted quantitative analysis by ultra-high performance liquid chromatography coupled with hybrid quadrupole time-of-flight mass spectrometry (UHPLC/QTOFMS). Still rarely used for this purpose, this technique nevertheless offers excellent quantitative performance with high selectivity, but requires two separate injections for the same sample, one in the negative electrospray ionization mode (ESI-), and the other in the positive mode (ESI+). Two analytical methods were thus developed to cover 40 substances corresponding to 23 different pesticides plus nicotine and cotinine. The first method allows the determination of 15 biomarkers (SPE on a weak anion exchange polymeric support; ESI- mode) and the second 27 (SPE on a reverse phase polymeric support; ESI+ mode) with detection limits for a 2-mL urine sample varying from 0.02 to 25 μg.L−1. Replicate analysis of three pools of urine non-spiked and spiked at an intermediate level on about 20 different days showed most often excellent performance in terms of inter-day precision (<30%) and accuracy (between 80 and 125%), confirming that the UHPLC/QTOFMS coupling is perfectly adapted to a targeted quantitative analysis. The proposed methods were then applied to fifteen real urine samples, demonstrating the presence of pesticides, predominantly in metabolized form, in the urine of French pregnant women, and the capabilities of the proposed methods to detect them. They were finally applied to a study of the impact of thawing/freezing cycles on the conservation of the target substances, showing for the first time to our knowledge that the thawing/freezing cycles and the composition of urine samples could have an influence on the stability of some of the target substances. [ABSTRACT FROM AUTHOR]