N-nitrosamines And Illegal Food Additives, Basic Orange Ii By Gc / Ms Method

The dissertation is composed of two parts.Part 1.Determination of Nitrosamines by GC/LRMSNitrosamines are a group of organic compounds with a special segment of N-NO, which are widely spread in surrounding mediums,such as air,water,food,tobacco, etc.Nitrosamines are potent carcinogens which can induce liver tumour in various species and are toxic to human beings.Because Gas Chromatography with Low-resolution Mass Spectrometry(GC/LRMS) is greatly used in laboratories in China's quality inspection system,it is favorable to establish a reliable method to determinate nitrosamines based on GC/LRMS.In order to obtain accurate qualitative and quantitative results by GC/LRMS, nitrosamines were converted to derivatives of toluenesulfonamide by two-step derivatization,which greatly improved their chromatographic behavior and enhanced selectivity and sensitivity of mass spectrometry.Nitrosamines in water samples were first extracted by SPE cartridge filled with Ambersorb,then denitrosated by denitrosation reagents(HBr + HAc) to produce corresponding secondary amines, followed with reaction with p-Toluenesulfonyl chloride to form final derivatives, which were analysed by GC/LRMS coupled with Electron Impact Source(EI).Comparing with original nitrosamines,derivatives showed better behavior in GC: retention time were delayed,and NDPA,NPIR,NMOR were separated in baseline while they were overlapped without derivatization;besides,selectivity and sensitivity of MS were improved,due to more special ions,increasing response,better S/N. These improvements cut down the interference to quantitation from matrix,and limits of detection had been decreased in 1 or 2 order of magnitude,at the level of 0.05 ng/mL.The method were successfully applied to detect 8 nitrosamines in tap water samples,the recovery spiked at 0.4 ng/mL ranged from 67%to 79%,which demonstrated robust competence according to rules of AOAC and EPA.Part 2.Determination of the illegal food colorant,Chrysoidine,in food by GC/MSChrysoidine dye,with another name of Basic OrangeⅡ,is an azo dye which is widely used in chemical industries,such as wools,furs,silk,etc.Because of its carcinogenicity,Chrysoidine is forbidden to be used in food industries as colorants. But some lawless dealers employed chrysoidine to dye some food,such as fish and bean curd,to obtain bigger profits,which did great damage to public food safety.In this paper,we established a reliable method to determinate chrysoidine in food by GC/MS.Samples were extracted by dispersive-SPE with C18,followed by vaporization to dryness under nitrogen stream.Then chrysoidine was reacted with acetic anhydride, with the help of pyridine,to form derivatives of amide.Afterwards,the final derivative was injected for GC/MS analysis.LOD of proposed method was 2.3μgkg^-1, RSD was 2.1-4.1%,and recovery ranged from 81-91%,which showed its advantage of simplicity,low-cost,high-sensitivity and accurate quantitation.The proposed method was first reported to determinate chrysoidine by GC/MS. Comparing with HPLC and LC-MS/MS,this method supplied more special ions, which would give more identification in qualitative and quantitative analysis.Besides, GC/MS are widely equipped in laboratories,which endow the proposed method with good popularity and authentic application.