Simultaneous analysis of urinary phthalate metabolites of residents in Korea using isotope dilution gas chromatography-mass spectrometry.
Phthalates are used in industry products, household items, and medical tools as plasticizers. Human exposure to phthalates has raised concern about its toxicity. In the present study, optimization was conducted for the simultaneous analysis of eight kinds of phthalate metabolites using gas chromatography-mass spectrometry (GC-MS): MEP, MiBP, MnBP, MBzP, MiNP, MEHP, MEOHP, and MEHHP. In order to minimize the matrix effect and to do quantitative analysis, isotope dilution and LLE-GC-MS methods were performed. Urine samples were enzymatically hydrolyzed, extracted with a mixture of n-hexane and ethyl ether (8:2; v:v), and subsequently derivatized with trimethylsilylation. All eight kinds of analytes showed clear resolution and high reproducibility in GC-MS results. The method detection limit ranged from 0.05 ng/mL to 0.2 ng/mL. Calibration curves were found to be linear from 0.2 to 100 ng/mL with -(2)>0.992. The relative standard deviation of the intraday precision using water and urine ranged from 2.1% to 16.3%. The analysis was performed with urine samples that were collected from adults residing in the Republic of Korea. The analyzed concentration results were compared according to gender and region. As a result, DEHP metabolites showed the highest detected concentration (75.92 μg/g creatinine, 100%), and MiNP, a metabolite of DiNP, showed the lowest detected concentration (0.42 μg/g creatinine, 22.5%). On average, female urine (200.76 μg/g creatinine) had a higher detected concentration of ∑8 phthalate metabolites than male urine. Samples from rural regions (211.96 μg/g creatinine) had higher levels than samples from urban regions.
Molecular Recognition Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Republic of Korea.
Miok
M
Kim
Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East Box 951569, Los Angeles, CA 90095-1569, USA.
Na Rae
NR
Song
Department of Chemistry, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul, 136-701, Republic of Korea.
Jong-Ho
JH
Choi
Molecular Recognition Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Republic of Korea.
Jeongae
J
Lee
Molecular Recognition Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Republic of Korea. Electronic address: phs3692@kist.re.kr.
Heesoo
H
Pyo
D000328:Adult; D004781:Environmental Exposure / Q000032:analysis* / Q000706:statistics & numerical data; D004785:Environmental Pollutants / Q000652:urine*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008297:Male; D010795:Phthalic Acids / Q000652:urine*; D010968:Plasticizers / Q000378:metabolism*; D056910:Republic of Korea
D004785:Environmental Pollutants; D010795:Phthalic Acids; D010968:Plasticizers; C032279:phthalic acid
Biomonitoring; Gas chromatography–mass spectrometry; Isotope dilution; Trimethylsilylation; Urinary phthalate metabolites