A method for the quantification of biomarkers of exposure to acrylonitrile and 1,3-butadiene in human urine by column-switching liquid chromatography–tandem mass spectrometry

Abstract

1,3-Butadiene and acrylonitrile are important industrial chemicals that have a high production volume and are ubiquitous environmental pollutants. The urinary mercapturic acids of 1,3-butadiene and acrylonitrile-N-acetyl-S-(3,4-dihydroxybutyl)cysteine (DHBMA) and MHBMA (an isomeric mixture of N-acetyl-S-((1-hydroxymethyl)-2-propenyl)cysteine and N-acetyl-S-((2-hydroxymethyl)-3-propenyl)cysteine) for the former and N-acetyl-S-2-cyanoethylcysteine (CEMA) for the latter-are specific biomarkers for the determination of individual internal exposure to these chemicals. We have developed and validated a fast, specific, and very sensitive method for the simultaneous determination of DHBMA, MHBMA, and CEMA in human urine using an automated multidimensional LC/MS/MS method that requires no additional sample preparation. Analytes are stripped from urinary matrix by online extraction on a restricted access material, transferred to the analytical column, and subsequently determined by tandem mass spectrometry using labeled internal standards. The limits of quantification (LOQs) for DHBMA, MHBMA, and CEMA were 10 microg/L, 2 microg/L, and 1 microg/L urine, respectively, and were sufficient to quantify the background exposure of the general population. Precision within series and between series for all analytes ranged from 5.4 to 9.9%; mean accuracy was between 95 and 115%. We applied the method on spot urine samples from 210 subjects from the general population with no occupational exposure to 1,3-butadiene or acrylonitrile. A background exposure of the general population to acrylonitrile was discovered that is basically influenced by individual exposure to passive smoke as well as active smoking habits. Smokers showed a significantly higher excretion of MHBMA, whereas DHBMA levels did not differ significantly. Owing to its automation, our method is well suited for application in occupational or environmental studies.

Analysis of 18 urinary mercapturic acids by two high-throughput multiplex-LC-MS/MS methods

“…Moreover, our data confirm recent findings showing significant differences between smokers and non-smokers for AAMA [22], GAMA [34], 2-HPMA [22], 3-HPMA [22], AMCC [22], CEMA [21], SPMA [7], HMPMA [33], and 1-/2-MHBMA [24]. In accordance with the literature, for DHBMA, similar concentrations in smokers and nonsmokers were observed [21,27].…”

“…In accordance with the literature, for DHBMA, similar concentrations in smokers and nonsmokers were observed [21,27]. On the one hand, DHBMA may be formed from endogenous butadiene-diol [35]; on the other hand, there are other exogenous sources apart from 1,3-butadiene, namely 2-chloroprene and epichlorohydrine, two chemicals mainly used in polymer synthesis [36].…”

“…Although numerous methods for the quantification of different MAs by LC-MS/MS have been reported in the recent past, the majority of those assays target a rather small set of up to six MAs [8,17,[20][21][22][24][25][26]. In addition, many of these methods lack the capability of quantifying MAs from environmental exposures in low levels.…”

Determination of six hydroxyalkyl mercapturic acids in human urine using hydrophilic interaction liquid chromatography with tandem mass spectrometry (HILIC–ESI-MS/MS)

“…It is reported that the high organic content of the solvent may significantly increase the sensitivity in ESI-MS detection [34,35]. In comparison to common RP-columns [17,24,36] best peak shapes, highest intensities and a significantly better separation from urinary interferences for the studied mercapturic acids were obtained on a HILIC column. Retention of the analytes on a HILIC column is strongly dependent on chromatographic conditions like the level of acetonitrile in mobile phase, used buffer-type, its concentration and pH-value.…”

“…1). Schettgen et al [36] noticed as well that in human urine samples one MHBMA peak is clearly predominant and they conclude that this might be due to differences between the purchased standard substance and the metabolic in vivo reaction. Ding et al [39] observed similarly only one MHBMA peak in human urine.…”