title: Analysis of tetrahydroxylated benzo[a]pyrene isomers in hair as biomarkers of exposure to benzo[a]pyrene.
abstract: A first gas chromatography-tandem mass spectrometry (GC-MS/MS) method was designed for analysis of four tetrahydroxylated benzo[a]pyrene metabolites (benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydrotetrol, benzo[a]pyrene-r-7,t-8,t-9,t-10-tetrahydrotetrol, benzo[a]pyrene-r-7,t-8,c-9,c-10-tetrahydrotetrol, and benzo[a]pyrene-r-7,t-8,c-9,t-10-tetrahydrotetrol) in hair. Hair powder extract was submitted to liquid-solid extraction, followed by C18 solid-phase purification. The analytes were derivatized with use of N-methyl-N-(trimethylsilyl)trifluoroacetamide and then analyzed by GC-MS/MS in negative chemical ionization mode. The calibration curve was linear from the limit of quantification (LOQ) to 20 pg/mg in hair. The coefficient of determination of the calibration curve was more than 0.975 for all the analytes investigated. The LOQs ranged from 0.075 to 0.2 pg/mg in hair. The method was afterward applied to the analysis of hair of 16 rats randomly allocated to experimental groups receiving 16 polycyclic aromatic hydrocarbons solubilized in oil at 0 or 0.8 mg/kg body weight by oral administration three times per week for 90 days. The analysis of monohydroxylated and dihydroxylated benzo[a]pyrenes was conducted in parallel by GC-MS/MS on the same samples. All tetrahydroxylated benzo[a]pyrene isomers were detected in hair samples collected from rats exposed to polycyclic aromatic hydrocarbons. Benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydrotetrol, the most abundant isomer in hair of treated rats, was also the principal isomer released in DNA adduct hydrolysis in humans. Moreover, the benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydrotetrol concentrations in hair were significantly greater than those of 2-hydroxybenzo[a]pyrene, 1-hydroxybenzo[a]pyrene, 7-hydroxybenzo[a]pyrene, and 4-hydroxybenzo[a]pyrene and similar to those of 9-hydroxybenzo[a]pyrene and 3-hydroxybenzo[a]pyrene. The method was also sufficiently sensitive to monitor environmental levels of exposure because two hair specimens in the eight analyzed from smokers were above the LOQ for benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydrotetrol and benzo[a]pyrene-r-7,t-8,c-9,t-10-tetrahydrotetrol. This study therefore demonstrated that tetrahydroxylated benzo[a]pyrenes in hair might be a useful biomarker for the assessment of both the general population and occupationally exposed workers.
authors: Human Biomonitoring Research Unit, Luxembourg Institute of Health, House of Biohealth, rue Henri Koch 29, 4354, Esch-sur-Alzette, Luxembourg. nathalie.grova@lih.lu.
authors: Nathalie
authors: N
authors: Grova
authors: Human Biomonitoring Research Unit, Luxembourg Institute of Health, House of Biohealth, rue Henri Koch 29, 4354, Esch-sur-Alzette, Luxembourg.
authors: Emilie M
authors: EM
authors: Hardy
authors: Human Biomonitoring Research Unit, Luxembourg Institute of Health, House of Biohealth, rue Henri Koch 29, 4354, Esch-sur-Alzette, Luxembourg.
authors: Pauline
authors: P
authors: Meyer
authors: Human Biomonitoring Research Unit, Luxembourg Institute of Health, House of Biohealth, rue Henri Koch 29, 4354, Esch-sur-Alzette, Luxembourg.
authors: Brice M R
authors: BM
authors: Appenzeller
mesh_terms: D000328:Adult; D000818:Animals; D001564:Benzo(a)pyrene / Q000031:analogs & derivatives / Q000032:analysis*; D015415:Biomarkers / Q000032:analysis; D002648:Child; D004781:Environmental Exposure / Q000032:analysis*; D004785:Environmental Pollutants / Q000032:analysis*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006197:Hair / Q000737:chemistry*; D006801:Humans; D006900:Hydroxylation; D007536:Isomerism; D057230:Limit of Detection; D008297:Male; D008875:Middle Aged; D051381:Rats; D020318:Rats, Long-Evans; D055815:Young Adult
chemical_list: D015415:Biomarkers; D004785:Environmental Pollutants; D001564:Benzo(a)pyrene
keywords: Gas chromatography–tandem mass spectrometry; Hair analysis; Polycyclic aromatic hydrocarbons; Rat model; Tetrahydroxylated benzo[a]pyrenes