Direct Analysis of Conjugated Metabolites to Evaluate Ortho-Phenylphenol (OPP) Exposure in Human Urine

摘要

Ortho-PhenylPhenol (OPP) has been widely used as a fungicide and preservative. Two facts: low dose studies have demonstrated a low toxicity in animals and humans but high dose exposure to this contaminant has toxic effects such bladder cancer. Thus far, monitoring of OPP exposure in the general population has been performed by measuring OPP after urine hydrolysis with the B-glucuronidase/arylsulfatase enzyme (mostly) and sometimes by the use of a mineral acid. We developed a sensitive, accurate and robust method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to specifically measure OPP metabolites excreted in human urine, the sulfate (OPP-S) and glucuronide (OPP-G) species. Comparative analysis of urine using a direct method and chemical hydrolysis method previously developed in our laboratory showed no significant difference in OPP concentrations. Moreover, a significant difference showed that underestimation of OPP level occurs when p-glucuronidase/arylsulfatase enzyme deconjugation is used. Then, different epidemiological studies may show different levels of exposure depending of methodological approach used.