title: Automated determination of ethyl carbamate in stone-fruit spirits using headspace solid-phase microextraction and gas chromatography-tandem mass spectrometry.
abstract: A fully automated procedure using headspace solid-phase microextraction (HS-SPME) followed by gas chromatographic/tandem mass spectrometric (GC/MS/MS) detection was developed for the determination of the toxic contaminant ethyl carbamate (EC) in stone-fruit spirits. After addition of deuterated internal standard, the optimised HS-SPME extraction with carbowax/divinylbenzene fibres (30 min at 70 degrees C) was done applying salting out with sodium chloride in the presence of pH 7 buffer solution. For quantitative analysis the characteristic fragmentations of m/z 74>44 and m/z 62>44 for ethyl carbamate as well as m/z 64>44 for ethyl carbamate-d5 were monitored in the multiple reaction monitoring (MRM) mode using a triple quadrupole instrument. In the validation studies, ethyl carbamate exhibited good linearity with a regression coefficient of 0.998. The limits of detection and quantitation were 0.03 and 0.11 mg/l. The precision never exceeded 4.3% (intraday) and 8.2% (interday) at any of the concentrations examined. A good agreement of analysis results in comparison to conventional sample clean-up over diatomaceous earth columns was found (R = 0.956, Bias = 0.08 mg/l). The new HS-SPME/GC/MS/MS procedure is suitable for the fast, reliable and inexpensive determination of ethyl carbamate in alcoholic beverages in an automated, and therefore, convenient procedure.
authors.affiliation: Chemisches und Veterinäruntersuchungsamt (CVUA) Karlsruhe, Weissenburger Str. 3, D-76187 Karlsruhe, Germany. Lachenmeier@web.de
authors.forename: Dirk W
authors.initials: DW
authors.lastname: Lachenmeier
authors.forename: Uta
authors.initials: U
authors.lastname: Nerlich
authors.forename: Thomas
authors.initials: T
authors.lastname: Kuballa
mesh_terms: D000434:Alcoholic Beverages / Q000032:analysis*; D001331:Automation; D005591:Chemical Fractionation / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D014520:Urethane / Q000032:analysis*
chemical_list: D014520:Urethane