Method for determining monohydroxybenzo[a]pyrene isomers using column-switching high-performance liquid...

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Biomarker Analysis

Background:

• Polycyclic Aromatic Hydrocarbons (PAHs) are environmental pollutants.
• Benzo[a]pyrene (BaP) is a carcinogenic PAH.
• Metabolites of BaP, such as monohydroxybenzo[a]pyrenes (OHBaPs), are important biomarkers of exposure.

Purpose of the Study:

• To develop and validate a sensitive method for determining OHBaP isomers.
• To identify and quantify OHBaP metabolites in human urine.
• To assess the utility of OHBaPs as biomarkers of PAH exposure.

Main Methods:

• Column-switching high-performance liquid chromatography (HPLC) with fluorescence detection.
• Separation of 11 OHBaP isomers using reversed-phase and cyclodextrin-bonded columns.
• Selective adsorption of analytes on blue rayon from urine matrix followed by methanol elution.

Main Results:

• The method achieved low detection limits (0.3-8 pg/injection) for OHBaPs.
• 1-, 3-, and 9-OHBaPs were identified as major in vitro metabolites of BaP.
• Only 3-OHBaP was detected in human urine, quantified at 0.5 ng/g creatinine.
• High accuracy (95.5-100.9%) and precision (2.4-3.9%) were achieved for 3-OHBaP and 1-hydroxypyrene (1-OHP) determination.
• Recoveries of OHBaPs and 1-OHP using blue rayon were superior to solid-phase extraction.

Conclusions:

• The developed column-switching HPLC method is effective for sensitive and selective determination of OHBaP isomers.
• 3-OHBaP is a relevant biomarker for BaP exposure in humans.
• The method allows for simultaneous analysis of OHBaPs and 1-OHP, a known PAH exposure biomarker.