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1,3-Butadiene (BD) is a ubiquitous environmental pollutant found in tobacco smoke. In vivo, BD is mainly metabolized to form monohydroxybutenylmercapturic acid (MHBMA) and N-acetyl-S-(3, 4-dihydroxybutyl) cysteine (DHBMA). The accurate quantification of MHBMA and DHBMA in urine may provide important insights into the actual internal exposure of the general population to BD. 8-Hydroxy-2-deoxyguanosine (8-OHdG) is the biomarker of oxidative damage. In this study, a column-switching LC-MS/MS method was developed and validated for the simultaneous quantification of MHBMA, DHBMA derived from BD exposure and 8-OHdG in human urine. Urine samples were loaded on a LiChrospher(®) RP-8 ADS (25μm) 25×4mm RAM column for the extraction and clean-up of analytes. The separation was achieved using a SUPELCO(®) LC-18-DB column (75mm×3.0mm, 3μm). The analytes were ionized in negative electrospray ionization mode and analyzed in multiple reaction monitoring mode. Under optimum conditions, recoveries ranged from 78.9% to 101.7%, with relative standard deviations less than 11%. The limits of quantification ranged from 0.15 to 0.27ng/mL, highlighting the high sensitivity of this simple method. The validated method was successfully applied to analysis urine samples from 56 non-smokers and 233 smokers who smoked cigarettes with 3 different tar yields. There was a correlation between urinary MHBMA, DHBMA and 8-OHdG. This method did not require any preparation process and efficiently removed interference from the matrix by using column-switching. The developed method is applicable to epidemiological studies., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Acrylonitrile, acrolein, 1,3-butadiene, benzene, and crotonaldehyde are hazard volatile organic compounds in tobacco smoke, which can be metabolized to mercapturic acids (MAs) excreted in urine. MAs are can be regarded as important and specific biomarkers to evaluate exposure to those carcinogenic volatile organic compounds. A simultaneous determination of N-acetyl-S-2-cyanoethyl-cysteine (CEMA), 3-hydroxypropyl)-L-cysteine (3-HPMA), N-acetyl-S-(3,4-dihydroxybutyl)-L-cysteine (DHBMA), N-acetyl-S-(phenyl)-L-cysteine (SPMA) and 3-hydroxy-1-methylpropylmercapturic acid (HMPMA) derived from five volatile organic compounds by column-switching LC-MS/MS has been described. MAs were concentrated and cleaned up by an online reusable pre-column packed with restricted access material. The intra- and inter-day precisions of the method ranged from 0.7% to 15.2%. The LODs was 0.013-0.053 ng/mL. The recovery of the whole analytical procedure ranged from 79.3% to 116%. After validation, this method was successfully applied to urine samples from smokers (n=246) and nonsmokers (n=58). The results showed MAs in urine from smokers were significantly higher than that in nonsmoker except for SPMA. Urinary CEMA significantly correlated with 3-HPMA (r=0.763, P<0.0001) and HMPMA (r=0.910, P<0.0001). CEMA, 3-HPMA and HMPMA are potential biomarkers to distinguish the differences between smokers and nonsmokers., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Abstract: 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) is an efficient biomarker of tobacco-specific carcinogen 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). The ability to monitor biomarker concentrations is very important in understanding potential cancer risk. An analytical method using molecularly imprinted polymer (MIP) column coupled with liquid chromatography/tandem mass spectrometry (LC–MS/MS) for the determination of total NNAL in human urine was developed and validated. The combination of MIP column extraction and LC–MS/MS can provide a high sensitive and relatively simple analytical method. The limit of detection (LOD) was 0.30pg/ml and analysis time was 6min. The method has been applied to urine samples of 36 nonsmokers and 207 smokers. NNAL was found to be significantly higher in the urine of smokers compared with nonsmokers. Compared with smokers with blended cigarettes, Chinese virginia cigarettes smokers had low urinary NNAL levels. There was a direct association between the 24-h mouth-level exposure of carcinogen NNK from cigarette smoking and the concentration of NNAL in the urine of smokers. However, there was not a positive correlation between urinary total NNAL levels in 24h and tar. Total urinary NNAL is a valuable biomarker for monitoring exposure to carcinogenic NNK in smokers and in nonsmokers. A prediction model of cigarette smoke NNK and urinary average NNAL levels in 24h was established (y =2.8987x −245.38, r 2 =0.9952, n =204). [Copyright &y& Elsevier]

In order to accurately assess the thermal maturity of highly/over-mature shales in Paleozoic strata in southern China, hydrothermal experiments of shale samples from the Dalong Formation from bed 18 of well-exposed Shangsi PTB Section was conducted in a semi-open system under various conditions of geological constraint. The saturated extracts of pyrolyzed shale samples were subjected to gas chromatography and mass spectrometry (GC-MS) analyses. The results indicated that hydrothermal experiments of Dalong shales in the presence of fluid pressure (FP), lithostatic stress (LS), water, catalyst of clay minerals and trace elements, is partially equivalent to catalytic hydropyrolysis in terms of the catalytic hydrogen effect for the release of bound biomarkers from geomacromolecules of kerogen and asphaltene. The evolutional trend of maturity-related biomarkers were classified into the following three categories: (a) the most common maturity parameters (e.g., Ts/(Ts + Tm) and C 29 S/(S + R)) initially increased and then decreased with a pyrolysis temperature (450 °C) at the reversal point during maturation; (b) the parameters (e.g., C 32 S/(S + R)) primarily increased or decreased and reached a temperature (400 °C) of tuning point, and then remained unaltered with increasing temperature (c) the parameters (e.g., C 27 DS/S); firstly increased, and then declined at a specific turning point temperature (425–500 °C), and thereafter continued to increase until the end of heating process. As a result, the threshold temperature for the release of bound sterane or terpane occurred in the range 400–500 °C. Most maturity-related sterane and terpane biomarker parameters cannot be applied to evaluate the maturity of highly/over-mature shale. However, the C 30 M/C 30 H ratio and S/T ratio, which are strongly correlated with temperature, may be employed to assess extremely mature shale from these Paleozoic strata due to the integrated effects of multiple factors in the thermal evolution process of biomarkers. This is very important for the exploration and development of shale gas in southern China. Additionally, the values of several source-related biomarker parameters derived from C 27–29 regular steranes are relatively constant during maturation, such as the ternary plot of the C 27–29 αααR sterane versus the C 27 /C 29 αααR sterane ratio. These are useful indicators for distinguishing the genetic source of highly/over-mature shales. • Hydrothermal experiment of Dalong shales under geological constraint is partially equivalent to catalytic HyPy. • C 30 M/C 30 H ratio and S/T ratio may be employed to assess extremely mature shale from Paleozoic strata in southern China. • Source-related biomarker parameters derived from C 27–29 regular steranes could be useful for highly/over-mature shales. [ABSTRACT FROM AUTHOR]

Abstract: The acrylonitrile metabolites 2-cyanoethylmercapturic acid (CEMA) and 2-hydroxyethylmercapturic acid (HEMA) have been determined in human urine using an automated column-switching procedure. A diluted sample was centrifuged just prior to being injected into a reusable precolumn packed with a restricted access material and coupled to a liquid chromatography–tandem mass spectrometry system. This method achieved satisfactory reproducibility and accuracy. Average intra- and interday variations (% relative standard deviations) ranged from 2.4 to 3.8% for CEMA and from 2.7 to 10.5% for HEMA. The limits of quantification were 0.003 and 0.099ng/ml for CEMA and HEMA, respectively. It was used to study the uptake of acrylonitrile from smoke constituents by both nonsmokers and smokers of different tar yield cigarettes under ISO 3308 smoking condition. Metabolite concentrations in smoker urine samples were approximately 12 times higher compared with those in nonsmokers for CEMA and 3 times higher for HEMA. Urinary CEMA levels show a clear dose–response relationship with daily cigarette consumption and urinary cotinine. CEMA can also discriminate between smokers of different ISO cigarettes. Because HEMA is not specific, it is only slightly related to smoking and acrylonitrile exposure. The validated biomarker CEMA will continue to be useful for studies of acrylonitrile uptake by smokers. [Copyright &y& Elsevier]