Studies On The Determination Of Trace Contaminants In Chemical Products With GC-MS

Gas chromatography-mass spectroscopy (GC-MS) is a yphenated analytical techniques, which is characterized inherently by unsurpassably high resolution, high sensitivity, and extremely strong identification capability. It has been used extensively in the environmental, medical, pharmacological, industry, athletics, and law enforcement fields. In this study, GC-MS was used for the determination of trace contaminants in chemical products with microwave assisted extraction as the method for sample preparation.The dissertation is divided into two sections: In the first section, a method was developed for the determination of trace amountof diethylene glycol in toothpaste samples by GC-MS and microwave extraction techniques. The conditions of microwave extraction and GC-MS were optimized, and the results are shown as follows: Toothpaste samples were microwave extracted with ethanol in 120℃for 20min. An Agilent HP-INNOWAX capillary column (30 m×0.32 mm×0.25μm) was employed for separation with temperature programming and ions including m/z 45.10, 75.10 and 76.10 were selected for measurement. The linear range of the method was 0.01 - 50.00 mg/ L with a detection limit of 0.005 mg/L, a quantification limit of 0.01 mg/L and relative standard deviation (RSD) of less than 1.6%. The method was applied to the determination of diethylene glycol in toothpaste with satisfactory results. The recovery varied from 95 % to 103 %.In the second section, a method was established to determine Phthalate Esters (PAEs) in Polyvinylchlorid (PVC) by GC-MS and microwave extraction techniques. Factors affecting the performance of microwave extraction and GC-MS were investigated and optimized, and conclusions are shown as follows: PVC samples were microwave extracted with a mixture of chloroform and methanol (2:1) in 120℃for 20min. An Agilent DB-5 capillary column (30 m×0.32 mm×0.25μm) were used for separation with temperature programming, and ions including m/z 149, 279, 293 and 307 were selected for measurement. The linear range of the method was 0.50-10.00 mg/ L. Detection limits of DBP, BBP, DEHP and DNOP were 0.10 mg/L, respectively, and their quantification limits were 0.25 mg/L; Detection limits of DINP and DIDP were 0.25 mg/L, and their quantification limits were 0.50 mg/L. The method was applied to the determination of PAEs in PVC with satisfactory results. The recovery varied from 90.67 % to 101.63 %, and RSD were between 2.32% and 1.6%.