Determination of dimethylsulfide and dimethylselenide in human urine by portable gas chromatography-photoionization detection with headspace sampling

A simple and sensitive method for the determination of dimethylsulfide (DMS) and dimethylselenide (DMSe) employing a gas chromatograph-photoionization detector with headspace sampling (HS-GC-PID) was developed. Parameters affecting the HS-GC-PID sensitivity including matrix effect, heating temperature, extraction time and carrier gas flow-rate were optimized. The matrix effect was required for standard addition calibration method for quantification purposes. The method has been validated when rectilinear relationship was between the concentrations of analytes and peak area in the range of 0.2-50 ng mL(-1) for DMSe and 0.5-100 ng mL(-1) for DMS, the correlation coefficients were from 0.995-0.998, and the limits of detection for DMS and DMSe were 25 pg mL(-1) and 48 pg mL(-1), respectively. The proposed method was further applied to quantification of DMS and DMSe in urine samples. (C) 2011 Elsevier B.V. All rights reserved.