High-pressure liquid chromatographic-mass spectrometric determination of sorbic acid in urine: verification of formation of trans,trans-muconic acid.
An LC-MS method is described for the determination of urinary sorbic acid (SA), a common food additive, which allows to measure down to 4 microg/L of the compound. The method involves an acidic hydrolysis followed by solid-phase extraction. The method was applied to two volunteers who ingested SA and to 36 individuals with no dietary restriction. The results confirm that a little aliquot of ingested SA is found in urine also in humans. The significant correlation found between urinary levels of SA and trans,trans-muconic acid (MA) seems to indicate that the measurement of SA in urine could allow to estimate the amount of MA excreted following a dietary intake of SA and, consequently, to enhance the specificity of MA as a biomarker of benzene exposure. A point of clarification in future studies will be the actual chemical form of SA excreted, since our results clearly demonstrate that without hydrolysis only a very little amount of SA can be found even in subjects heavily exposed to SA.
Negri
Sara
S
Research Laboratory on Airborne Pollutant (LabS-MEIA), Salvatore Maugeri Foundation-IRCCS, Via Ferrata 7, 27100 Pavia, Italy. snegri@fsm.it
Bono
Roberto
R
Maestri
Luciano
L
Ghittori
Sergio
S
Imbriani
Marcello
M
D000393:Air Pollutants; D001554:Benzene; D015415:Biomarkers; D002274:Carcinogens, Environmental; D002851:Chromatography, High Pressure Liquid; D004781:Environmental Exposure; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D013011:Sorbic Acid / Q000031:analogs & derivatives* / Q000032:analysis* / Q000378:metabolism / Q000493:pharmacokinetics; D016482:Urinalysis / Q000379:methods
D000393:Air Pollutants; D015415:Biomarkers; D002274:Carcinogens, Environmental; C005939:muconic acid; D001554:Benzene; D013011:Sorbic Acid