Analysis of 10 urinary BTEX metabolites using LC–MS/MS

Abstract

Benzene, toluene, ethylbenzene, and xylene (BTEX) are a group of volatile organic compounds that are ubiquitous in the environment due to numerous anthropogenic sources. Exposure to BTEX poses a health hazard by increasing the risk for damage to multiple organs, neurocognitive impairment and birth defects. Urinary BTEX metabolites are useful biomarkers for the evaluation of BTEX exposure, because of the ease of sampling and their longer physiological half-lives compared with parent compounds. A method that utilizes LC-MS/MS was developed and validated for simultaneously monitoring of 10 urinary BTEX metabolites. During the sample preparation an aliquot of urine was diluted with an equal volume of 1% formic acid; internal standard solution was added, and then the sample was centrifuged and analyzed.The analytes were separated on the Kinetex-F5 column by applying a linear gradient, consisting of 0.1% formic acid and methanol. The method was validated according to the FDA Bioanalytical Method Validation Guidance for Industry. The mean method's accuracies of the spiked matrix were 81-122%; the inter-day precision ranged from 4 to 20%; the limits of quantitation were 0.5-2 μg/L. The method was used for the evaluation of baseline levels of urinary BTEX metabolites in 87 firefighters.

Multiple Myeloma: Risk Factors, Pathogenesis and Relationship with Anti-myeloma Therapies

“…A periodic assessment of the Threshold Value-Time-Weighted Averages (TV-TWAs), Target Hazard Quotients (THQs) of these VOCs and their metabolites in exposed individuals and the environment will help in risk assessment of these potentially carcinogenic substances. [28][29][30][31][32][33][34][35][36][37] In addition, people working in agriculture, food processing, and chemical industries have a increased relative risk (RR) of 1.8 for developing MM. The RR is higher for people exposed to petrochemicals (RR = 3.7), asbestos (RR = 3.5) and laxatives (RR = 3.5).…”