Simultaneous determination of urinary hippuric acid, o-, m- and p-methylhippuric acids, mandelic acid and phenylglyoxylic acid for biomonitoring of volatile organic compounds by gas chromatography–mass spectrometry

• Published in: Analytica chimica acta Vol. 566; no. 2; pp. 167 - 171
• Main Authors: Ohashi, Yasuhiro, Mamiya, Tomoko, Mitani, Kurie, Wang, Bingling, Takigawa, Tomoko, Kira, Shohei, Kataoka, Hiroyuki
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 04.05.2006; Elsevier
• Subjects: Analytical chemistry; Chemistry; Chromatographic methods and physical methods associated with chromatography; Exact sciences and technology; Gas chromatographic methods; Gas chromatography–mass spectrometry; Hippuric acid; Mandelic acid; Methylhippuric acid; Phenylglyoxylic acid; Spectrometric and optical methods; Urine samples; Mandelic acid; Phenylglyoxylic acid; Urine samples; Hippuric acid; Gas chromatography–mass spectrometry; Methylhippuric acid; Capillary column; Metabolite; Hydrochloric acid; Ester; Ethylbenzene; Detection limit; Xylene; Standard curve; Monitoring; Methanol; Correlation coefficient; Human; Urine; Toluene; Interference; Volatile organic compound; Gas chromatography-mass spectrometry; Gas chromatography; Simultaneous measurement; Styrene; Mass spectrometry
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2006.03.018

A sensitive and precise method for the simultaneous determination of hippuric acid, o-, m- and p-methylhippuric acids, mandelic acid and phenylglyoxylic acid, which are major urinary metabolites of toluene, o-, m- and p-xylenes, styrene and ethylbenzene, respectively, was developed. These metabolites were converted into their methyl ester derivatives with methanol in hydrochloric acid, and then quantitated by gas chromatography–mass spectrometry (GC–MS) with selected ion monitoring using a DB-1 capillary column. The injected compounds were quantitatively and reproducibly resolved within 19 min with a detection limit of 8–27 pg. The calibration curves were linear in the range of 0.05–25 μg for each compound, with correlation coefficients above 0.9999. This method was successfully used to analyze small amounts of both rat and human urine samples without any interference from coexisting substances. Overall recoveries of these compounds spiked in urine samples were 92–104%. The analytical results of the contents of these metabolites in the rat and human urine samples are presented.