Measurement of methyl tert-butyl ether and tert-butyl alcohol in human blood by purge-and-trap gas chromatography-mass spectrometry using an isotope-dilution method.
We developed an isotope-dilution method for measuring methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) in whole human blood using a purge-and-trap gas chromatographic-mass spectrometric method. The labeled analogues for MTBE and TBA were [2H12]methyl tert-butyl ether and [2H9]-tert-butyl alcohol, respectively. Volatiles were removed from the blood by direct helium purging of the liquid; were trapped on a Tenax trap; and were desorbed, cryofocused, and chromatographed on a DB-624 capillary column that was connected directly to the ion source of a mass spectrometer. Detection was by mass analysis using a double-focusing magnetic-sector mass spectrometer operating in the full-scan mode at the medium mass resolution of 3000. For the isotope-dilution method, the minimum detection limits in blood (5-10 mL) are 0.01 microgram/L for MTBE and 0.06 microgram/L for TBA. The isotope-dilution method proved to be a big improvement in recovery, reproducibility, and sensitivity over our previous analytical method, which used the labeled ketone, [4-2H3]-2-butanone, as the internal standard for both MTBE and TBA. The isotope-dilution method has sufficient sensitivity for monitoring blood levels of MTBE and TBA in populations exposed to oxygenated fuels containing MTBE.
Bonin
M A
MA
Division of Environmental Health Laboratory Sciences, Centers for Disease Control and Prevention (CDC), Atlanta, GA 30341-3724, USA.
Ashley
D L
DL
Cardinali
F L
FL
McCraw
J M
JM
Wooten
J V
JV
D000440:Butanols / Q000097:blood* / Q000652:urine; D004987:Ethers / Q000097:blood* / Q000652:urine; D008401:Gas Chromatography-Mass Spectrometry / Q000295:instrumentation / Q000379:methods; D006801:Humans; D008738:Methyl Ethers; D020002:tert-Butyl Alcohol
D000440:Butanols; D004987:Ethers; D008738:Methyl Ethers; C043243:methyl tert-butyl ether; D020002:tert-Butyl Alcohol