Determination of ethyl carbamate in pickles using multiple headspace solid-phase microextraction coupled with gas chromatography

• 1、College of Food Science & Technology, Huazhong Agricultural University, Wuhan 430070

Abstract：A method has been developed for the quantitative determination of ethyl carbamate (EC) in pickles based on multiple headspace solid-phase microextraction (Multiple HS-SPME) coupled with gas chromatography. A novel anilino-methyl triethoxy silicane-methacrylic acid/terminated silicone oil (AMTEOS-MA/OH-TSO) fiber was developed by sol-gel technology and proved to be more efficient to EC than several commercial ones. An important problem still remained. The adsorption of EC by water in the samples caused low transport of analyte to the headspace, which made multiple HS-SPME invalidated. Mixing with anhydrous sodium sulphate, the sensitivity of the method was improved and the problem was solved. Serious matrix interference was observed among various types of pickles when the common SPME procedure was performed and multiple HS-SPME avoided the matrix effect by a complete recovery of the analytes. The linear range of the proposed method was 0.1-100 mg L-1, with a correlation coefficient of 0.9996. The precision gave satisfactory outcome of 4.25 % (n=5). The limit of detection was calculated for a signal-to-noise ratio (S/N) of 3 from the first extraction of the most diluted standard solution, and it was 0.038 mg L-1. Recoveries in five pickles ranged between 91.2-104.2%, statistically equivalent to those obtained by standard addition method. The study indicates that the multiple HS-SPME procedure is simple, convenient, accurate, and low-cost, and most of all, can be used for quantitative analysis in complex matrix without matrix effect.

Keywords： analytical chemistry multiple headspace solid-phase microextraction ethyl carbamate pickle matrix effect gas chromatography