US EPA

3483280 

Journal Article 

Analytical method for urinary metabolites as biomarkers for monitoring exposure to phthalates by gas chromatography/mass spectrometry 

Yoshida, T 

2017 

Yes 

Biomedical Chromatography
ISSN: 0269-3879
EISSN: 1099-0801 

31 

7 

E3910-E3910 

English 

27925246 

10.1002/bmc.3910 

WOS:000404968600006 

Phthalates, widely used as plasticizers, have been detected in indoor air, but there have been few reports on methods of analyzing urinary metabolites as biomarkers to monitor exposure to di-n-pentyl phthalate or di-n-hexyl phthalate. Presented here is a cost-effective and sensitive analytical method for the determination of urinary metabolites of phthalates containing these two compounds. Nine urinary phthalate metabolites were enzymatically hydrolyzed and extracted with toluene: monomethyl phthalate, monoethyl phthalate, monoisobutyl phthalate, mono-n-butyl phthalate, mono-n-pentyl phthalate, mono-n-hexyl phthalate, monocyclohexyl phthalate, monobenzyl phthalate and mono(2-ethyl-5-carboxypentyl) phthalate. After transformation to their tert-butyldimethylsilyl derivatives, they were analyzed by gas chromatography/mass spectrometry in the electron impact ionization mode. The calibration curves for the metabolites were linear at urinary concentrations of up to 30 μg/L, showing that they could be determined accurately and precisely (detection limits 0.1-0.4 μg/L, quantification limits 0.3-1.3 μg/L). The urine samples collected could be stored for up to 1 month at -20°C. The proposed analytical method was used to examine urine samples from seven healthy volunteers. This method should be useful for monitoring phthalate exposure in the general population. 

Biomarkers/urine; Calibration; Gas Chromatography-Mass Spectrometry/methods; Limit of Detection; Occupational Exposure; Phthalic Acids/urine; Reproducibility of Results; general population; plasticizer; tert-butyldimethylsilyl derivative