Evaluation of assays for the identification and quantitation of muconic acid, a benzene metabolite in human urine.
Muconic acid (MA) is a urinary metabolite of benzene and has been used as a biomarker of exposure to benzene in humans exposed to levels as low as 1 ppm. We have modified a high-pressure liquid chromatography (HPLC) based assay for urinary MA (Ducos et al., 1990) by the use of a diode array detector. This modification increases the specificity of the HPLC-based assay by identifying false positives. In addition, we have developed a gas chromatography (GC) based assay that uses a flame ionization detector (GC-FID). Both assays identified and quantified MA in human urine at concentrations greater than 40-50 ng/ml. Assay precision was within 10% relative standard deviation for MA concentrations above 90 ng/ml using the HPLC assay and above 40 ng/ml using the GC-FID assay. Quantitative accuracy of the assays was evaluated by determining MA in human urine samples using both methods and also a gas chromatography-mass spectrometry (GC-MS) procedure. Numerical correlation among the three assays was good at MA concentrations above 100 ng/ml.
Bartczak
A
A
University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Department of Environmental and Community Medicine, Piscataway.
Kline
S A
SA
Yu
R
R
Weisel
C P
CP
Goldstein
B D
BD
Witz
G
G
Bechtold
W E
WE
D001554:Benzene / Q000378:metabolism; D002250:Carbon Radioisotopes; D002849:Chromatography, Gas / Q000295:instrumentation / Q000379:methods*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005069:Evaluation Studies as Topic; D005410:Flame Ionization; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D012044:Regression Analysis; D012680:Sensitivity and Specificity; D013011:Sorbic Acid / Q000031:analogs & derivatives* / Q000032:analysis; D014556:Urine / Q000737:chemistry
D002250:Carbon Radioisotopes; C005939:muconic acid; D001554:Benzene; D013011:Sorbic Acid