[Isotopic dilution HPLC/MS/MS urinary trans, trans-muconic quantitative analysis among refinery workers].
The determination of trans, trans muconic acid (t,t-MA) in human urine, a biomarker suggested by the American Conference of Governmental Industrial Hygienists for occupational benzene exposure, with a limit value of 500 microg/g creatinine, is usually performed by means of gas or liquid chromatographic methods. Almost all the HPLC methods make use of strong ionic exchange cartridges for sample cleaning, reverse phase separation and detection either by UV at lambda = 259 nm or; more recently, by electrospray tandem mass spectrometry: yet, not all of these methods have been validated for quantitative analysis considering also the matrix effect. This paper presents the quantitative analysis of t,t-MA in 94 end-shift urine samples from workers of an oil refinery performed by means of an HPLC/MS/MS analytical method that uses a commercially available deuterium labeled isotope as internal standard, that during the validation has highlited the problem of interferences due to urine ion suppression effect and to the interference from isobaric ions both for the analyte and the internal standared. The following mean values have been obtained: 47.37 microg/g creatinine for non smokers non occupationally exposed to benzene, 97.40 microg/g creatinine for non smokers exposed to benzene, 142.38 microg/g creatinine for smokers non occupationally exposed and 149.08 microg/g creatinine for smokers occupationally exposed to benzene. The results obtained demonstrate that using this analytical method for urinary t,t,MA it is possible to discriminate among groups with different levels of benzene exposure, due to all the possible benzenene sources: environmetal, occupational, due to smoking, and their possible combinations.
Tranfo
G
G
ISPESL, Centro Ricerche di Monte Porzio Catone. giovanna.tranfo@ispesl.it
Paci
E
E
Pigini
D
D
D015415:Biomarkers / Q000652:urine; D002851:Chromatography, High Pressure Liquid; D019652:Extraction and Processing Industry; D006801:Humans; D016273:Occupational Exposure / Q000032:analysis*; D013011:Sorbic Acid / Q000031:analogs & derivatives* / Q000032:analysis
D015415:Biomarkers; C005939:muconic acid; D013011:Sorbic Acid