Application Of Gas Chromatography-Ion Trap/Mass Spectrometry In The Determination Of Phthalates And Preservatives In Food

Phthalates, mainly to make plastics soft and flexible, are widely used in industrial and consumer applications. At the same time, Parabens are widely used as antimicrobial preservatives in food, and, EEC has established a maximum admissible concentration(MAC)in food. Routine monitoring of these pollutants is required since they are chemical hazards to human health and environmental. In this investigation, a fast, convenient, and reliable analytical method for phthalates determination at very low concentrations in the dispensing systems and also in the environment is described, which includes a single-drop microextraction(SDME)sample preparation accompanied with GC-IT/MS.The main conclusions obtained were listed as follows:The application of GC-MS in food safety area was reviewed, which included the basic concepts, theories and current advances of GC-MS and SDME technique. In addition, research advance of phthalates esters and preservatives was summarized concisely.A novel, simple, fast and environment-friendly method based on single drop microextraction(SDME)was developed for the determination of phthalate esters in food. The effect of gas microdrop volume, the depth of microdrop in sample solution, extraction time and stirring rate on the extraction efficiency were investigated separately. The optimal SDME conditions with 2.0μL of toluene, 0.75 cm of the depth of microdrop, 1000r/min of stirring rate and 20 min of extraction time were obtained and used for the analysis of dimethyl phthalate(DMP), diethyl phthalate(DEP), di-n-butyl phthalate(DBP), dioctyl phthalate(DOP)and diethylhexyl phthalate(DEHP)in food. Firstly, a sample was dissolved with de-ionized water and then extracted with ultrasonication for 15 min. Then, it was filtrated and the solution was extracted and concentrated by a single drop of a solvent. Finally, it was analyzed by GC/MS. The reproducibility, linearity, recovery and limit of detection of the method were studied. The results showed that the limits of detection(LOD)were between 25 ng/L and 0.8 mg/L. The overall recoveries were 87.1％-114.4％with the relative standard deviations of 4.9％to 11.6％. This method was successfully applied to the analysis of food samples.Determination of preservatives in food samples was developed by GC-IT/MS. The accuracy of the SDME method was tested and compared to that of liquid-liquid extraction(LLE)by linear calibration curve, method detection limits(MDLs), the reproducibility and recovery.