| Aquatic food is nutritious, delicious, and has high protein, low fat, so it has a good balance in nutritious. Now, aquatic food is becoming an important protein source and important part in reasonable diet. Therefore, its security is critical to the public health. Harmful substances exiting in aquatic food such as environmental estrogens, steroids, microcystins and food additives were selected for study in this thesis. Based on high performance liquid chromatography-mass spectrometry (HPLC-MS) technology, several simple, rapid, and sensitive methods had been developed for these harmful substances detections. The thesis is consisted of the following five chapters:In the first chapter, there was an overview about harmful substances in aquatic food, including the status, standard limits and research progress. The pretreatment methods and liquid chromatography-mass spectrometry techonology was reviewed in detail. In addition, the research content and working significance of the thesis was summarized.In the second chapter, solid phase extraction technology-high performance liquid chromatography-quadrupole-time of flight mass (SPE-HPLC-Q-TOF-MS) method was established to determine the environmental estrogens in aquatic food. Conditions of solid phase extraction procedure (solid phase extraction column, washing and elution) and HPLC-Q-TOF-MS (mobile phase, gradient elution conditions, the column temperature, flow rate, etection mode, Fragmentor and collision energy) were investigated. Under optimal conditions, seven environmental estrogens were baseline separated within 8 min, with the minimal limit of detection of 0.5 ng/mL. This method was applied to analyze three fish samples. The results showed that bisphenol A and dienestrol were detected in all samples, while estradiol and estrone were detected in one or two samples. In addition, the tandem mass spectrometry (MS/MS) was used for speculating the fragmentation pathways of estrogens to validate compouds.In the third chapter, a LC-MS/MS method was established for the simultaneous determination of 16 hormone residues in fish. The detection limit of the method was less than 5.0 μg/L. This method was successfully applied to fish sample analysis, and hydrocortisone was detected in the sample.In the fourth part, a new method based on nano-flow chip LC combined with MS has been established to detect three microcystins. This method meets the requirements of the standard limit without any enrichment. Ultrasonic was used for extraction with 5% ammonium acetate, and then the extract solvent was purified by the solid phase extraction. The recoveries for three microcystins were between 82.8%-120.3%, showed that the method was reliable.In the last chapter, HPLC-QTOF-MS was used to detect four sweeteners and two antioxidants, the limits of detection were 0.25-5.0 ng/mL. Shredded kelp was selected as a sample, and 0.29 g/kg of sodium cyclamate in shredded kelp was measured, the spiked recovery was 100.3%-104.8%. With the MS/MS, false positive results in real samples can be avoided, so it has good practicality and can be promotion widely. |
PDF Full Text Request