Optimization of headspace solid-phase microextraction for analysis of ethyl carbamate in alcoholic beverages using a face-centered cube central composite design

The headspace solid-phase microextraction (HS-SPME) of ethyl carbamate from alcoholic beverages was optimized for the first time using a face-centered cube central composite design (CCD). The factors expected to influence the extraction process are discussed. Firstly, some of factors are fixed based on the opinion of expert and previous experiments, which reduce the number of factors and then avoid very complex response models and large variability. Secondly, for three remaining inexplicit factors, sample temperature, pH and %NaCl, a face-centered cube central composite design was performed and a response surface equation was derived. The statistical parameters of the derived model were r = 0.974 and F = 20.183. The optimum conditions were obtained using a grid method. Next, the method was analytically evaluated using the optimum conditions. The detection limit, relative standard deviation, linear range and recovery were 3 mu g L-1, 4.3-8.6%, 10-160 mu g L-1, and 92.8-97.5%, respectively Finally, the method was applied to a variety of alcoholic beverages. (C) 2008 Elsevier B.V. All rights reserved.