DETERMINATION OF o-CRESOL BY GAS CHROMATOGRAPHY AND COMPARISON WITH HIPPURIC ACID LEVELS IN URINE SAMPLES OF INDIVIDUALS EXPOSED TO TOLUENE

Amorim, Leiliane Coelho André; Alvarez-Leite, Edna Maria

doi:10.1080/009841097160438

Cited by 20 publications

(2 citation statements)

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“…A variety of analytical techniques have been used over the years to quantify o ‐cresol in hydrolyzed human urine. One widespread technique is gas chromatography with flame ionization detection (GC‐FID) 9–15 . Unfortunately, this technique often gives inconclusive results due to interference and limits of detection that are generally well above the current BEI.…”

Section: Introductionmentioning

confidence: 99%

“…One widespread technique is gas chromatography with flame ionization detection (GC-FID). [9][10][11][12][13][14][15] Unfortunately, this technique often gives inconclusive results due to interference and limits of detection that are generally well above the current BEI. Gas chromatography coupled with mass spectrometry detection 16,17 is also used, but it requires a stringent sample preparation procedure sensitive to water.…”

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confidence: 99%

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Ultrahigh‐performance liquid chromatography–tandem mass spectrometry quantitation of o‐cresol in hydrolyzed human urine to assess toluene exposure

Langlois

Gagné

2023

Rapid Comm Mass Spectrometry

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Rationale Toluene is a volatile organic compound used in domestic and industrial applications. The main routes of workplace exposure to toluene are inhalation and dermal contact. As toluene exposure can cause severe nervous system damage, its quantification is crucial to prevent occupational illness. Toluene is metabolized mainly as hippuric acid, S‐benzylmercapturic acid and epoxides. These are rapidly converted to o‐/p‐cresol, which is then excreted in the urine as conjugated glucuronides and sulfates. o‐Cresol and its conjugates can be chemically hydrolyzed to form free o‐cresol, which can then serve as a urinary biomarker of toluene exposure. Current analytical methods for quantifying o‐cresol in hydrolyzed urine are, however, either weakened by interference, are not sensitive enough or require water‐sensitive sample preparation. Development of a liquid chromatography–tandem mass spectrometry method for assessing exposure to toluene is thus required. Method Urine samples were acidified and heated to form free o‐cresol and then derivatized with dansyl chloride and diluted. Extracts were separated by reverse‐phase chromatography on a BEH phenyl column and then analyzed using a triple quadrupole instrument in selected reaction monitoring mode. Results The dansyl chloride derivatization step was optimized to produce the derivative within a reaction time of 3 min. Hydrolysis efficiency in forming free o‐cresol from conjugated metabolites was evaluated using o‐cresol‐β‐d‐glucuronidespiked human urine: complete hydrolysis occurred in 45 min. Dynamic range was 0.4 to 40 μM, and the method was useful for toluene monitoring in non‐occupational (0.1 μmol/mmol creatinine) as well as occupational (0.3 μmol/mmol creatinine) exposure. The calculated limit of detection and limit of quantitation of the method were 0.06 and 0.21 μM, respectively. Intraday and interday precisions were 3.2% and 4.4%, respectively. Method accuracy was established as 99% using ClinChek® urine controls. Conclusion An ultrahigh‐performance liquid chromatography–tandem mass spectrometry method for analysis of o‐cresol was developed for biological monitoring of toluene exposure in human urine. This is the method of choice used by occupational health and safety practitioners in the province of Québec, Canada.

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Section: Introductionmentioning

confidence: 99%

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confidence: 99%

Ultrahigh‐performance liquid chromatography–tandem mass spectrometry quantitation of o‐cresol in hydrolyzed human urine to assess toluene exposure

Langlois

Gagné

2023

Rapid Comm Mass Spectrometry

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Analysis of urinary aromatic acids by liquid chromatography tandem mass spectrometry

Crow

Bishop

Paliakov

et al. 2008

Biomedical Chromatography

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The separation and detection of 11 urinary aromatic acids was developed using HPLC-MS/MS. The method features a simple sample preparation involving a single-step dilution with internal standard and a rapid 8 min chromatographic separation. The accuracy was evaluated by the recovery of known spikes between 87 and 110%. Inter- and intra-assay precision (CV) was below 11% in all cases and the analytes were observed to be stable for up to 8 weeks when stored at -20 degrees C. The method was validated based upon linearity, accuracy, precision and stability and was used to establish reference intervals for children and adults.

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Validation of Hippuric Acid as a Biomarker of Toluene Exposure

Duydu

Süzen

Erdem

et al. 1999

Bulletin of Environmental Contamination and Toxicology

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DETERMINATION OF o-CRESOL BY GAS CHROMATOGRAPHY AND COMPARISON WITH HIPPURIC ACID LEVELS IN URINE SAMPLES OF INDIVIDUALS EXPOSED TO TOLUENE

Cited by 20 publications

References 12 publications

Ultrahigh‐performance liquid chromatography–tandem mass spectrometry quantitation of o‐cresol in hydrolyzed human urine to assess toluene exposure

Ultrahigh‐performance liquid chromatography–tandem mass spectrometry quantitation of o‐cresol in hydrolyzed human urine to assess toluene exposure

Analysis of urinary aromatic acids by liquid chromatography tandem mass spectrometry

Validation of Hippuric Acid as a Biomarker of Toluene Exposure

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