Highly Sensitive And Rapid Determination Of Multiple Kinds Of Food Additives And Its Application To Real Samples

In recent years, the food safety issues induced by abusing food additives have caused worldwide concern. In this dissertation, some methods using advanced instruments and equipments for food additives preparation and analysis have been developed, and which have also been applied to determining foods additive in real samples. This work was useful to prevent abusing food additives, to promote the development of food industry and protect human health.The definition, classification and function of food additives were introduced. Besides, a detail summary of analytical methods for the pretreatment and determination of food additives were also given.For the sweeters in beverages and wines, an ultra performance liquid chromatography-photo diode array (UPLC-PDA) method and a high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method were developed respectively. The base line separation was achieved in less than five minutes. The results indicated that five kinds of artificial sweaters were detected by mass spectrometry in electrospray ionization mode (ESI) using ammonium formate buffer was more sensitive than ammonium acetate. The LOD of acesulfame, sodium cyclamate, aspartame and neotame were20,5,60,100μg/L by UPLC-PDA and the LOD of acesulfame, saccharin sodium. sodium cyclamate, aspartame and neotame were 0.6,5,1,0.8 and 0.2μg/L, respectively. When applying these methods to real samples, acesulfame, sodium cyclamate, aspartame and neotame were detected.For preservatives, solid phase membrane extraction was used for the enrichment and purification in the first time, this pretreated method had demonstrated an 15 times improvement for analysis throughout than traditional solid phase column extraction methd. An UPLC-PDA method was developed for determination of ten preservatives such as benzoic acid and sorbic acid in food. The separation was achieved in ten miniutes, and the p-hydroxy-benzoic acid butyl ester and p-hydroxy-benzoic acid isobutyl ester were base-line separated for the first time. The analytical results of samples indicated that 12 samples were positive in 18 samples, and their concentrations were not over the limit.For synthetic colorants, an UPLC-DAD-MS/MS method was developed to detect synthetic colorants in shrimp flakes, the method demonstrated that the using of a both hydrophilic and lipophilic solid phase extraction column for sample purification could achieve a good recoveries, and based on the DAD and MS/MS dual-detector method for quantitative of these colorants, the accuracy and sensitivity were greatly improved.Based on high-resolution time of flight mass spectrometry, the methods for determination of 18 preservatives in drinks and 11 antioxidants in vegetable oil were established by LC-TOF methods respectively. This method first achieved the retention time, the optimum ion mode and accurated molecular ion mass values by single standard injection, then identified the unknown sample compounds by their chromatographic retention time and the exact molecular ion mass value. Based on a segmented collision voltage process, the accuracy of analyzed food additves are less than 5 ppm. This method has been successfully applied in practical samples for screening of preservatives and antioxidants.