Study And Application Of Analytical Method For Polybrominated Biphenyls And Polybrominated Diphenyl Ethers Residue In Food And Electrical And Electronic Products By Gas Chromatography-Mass Spectrometry

People pay more attention to their own health because of the progress of the society, at the same time, people know more about the food security problem because of the development of science and technology. The food security not only affects the healthy of the consumer, but also affects progress of the international food trade, even affects the stabilization of the society. So the food security problem has been the hot problem all over the world. This dissertation focused on the analytical methods study and application on the polybrominated biphenyls (PBBs) and Polybrominated Diphenyl Ethers (PBDEs) residue in food.This thesis focused on the studies of ultrasonic extraction technology used in the sample pretreatment and the optimization of the analytical conditions of gas chromatography mass spectrometry (GC-MS). The method for the multiresidue determination of PBBs and PBDEs in food had been established. The thesis consisted of six chapters.The first chapter, simply introduced the study of PBBs and PBDEs Environmntal Incretion in China and abroad. The conception, research development, classed and pollution harmfulness of Environmental Incretion was explained. The character, application, toxicity, pollution status and analytical method of PBBs and PBDEs was interpreted. Contemporarily, the problems and the meaning of the task was introduced. Then we made an expectation. At last, the content of the study was briefly shown.The second chapter, briefly introduced the basic principle of the mass spectrum unscrambling, and in order to offer the structure information for the PBBs and PBDEs residue, analysed the negative chemical ionization mass spectrum (NCI-MS) unscrambling of 10 PBBs and PBDEs. This part briefly introduced the establishment of the analytical method, Gas Chromatography-Negative Chemical Ionization-Mass Spectrometry-Selected Ions Monitoring (GC-NCI-MS SIM). It was presented that the possibility and necessity of the application of gas chromatography negative chemical ionization mass spectrometry (GC-NCI-MS) to the analysis of PBBs and PBDEs residues in food.The third chapter, an analytical multiresidue method for the simultaneous determination of 5 polybrominated diphenyl ethers (PBDEs) in fish oil was developed. PBDEs were extracted from fish oil with hexane and cleaned up on an acid silical gel column, then were determined by using a gas chromatography- mass spectrometry operated in negative chemical ionization mode and quantified in selective ion monitoring mode, and with PCB103 as internal standard. Meanwhile, fracture mechanism of some PBDEs negative chemical ionization mass spectrometry were evaluated. Recovery studies were performed at 20 and 100μg/kg fortification levels for each PBDEs, and the recoveries ranged from 88.6% to 111.3% with a relative standard deviation between 3.8% and 13.5% for the different PBDEs. The developed method was linear over the range assayed, 1～500μg/L, with determination coefficients > 0.9992. Finally, the developed analytical method has been successfully applied to the determination of PBDEs in several fish oil samples and the presence of three of the most abundant PBDEs has been observed (BDE47, BDE99 and BDE100).The forth chapter, an analytical multiresidue method for the simultaneous determination of 10 PBBs and PBDEs in eggs was developed. PBBs and PBDEs were extracted from eggs with hexane and cleaned up on an acid silical gel column, then were determined by using a gas chromatography-mass spectrometry operated in negative chemical ionization mode and quantified in selective ion monitoring mode, and with PCB-209 as internal standard. Recovery studies were performed at 5 and 50μg/kg fortification levels for each PBBs and PBDEs, and the recoveries ranged from 75.2% to 107% with a relative standard deviation between 2.04% and 8.76% for the different PBDEs. The developed method was linear over the range assayed, 1～250μg/L, with determination coefficients > 0.9991. Finally, the developed analytical method has been successfully applied to the determination of PBDEs in several eggs samples.The fifth chapter, an analytical method for brominated flame retardants in plastics was investigated using gas chromatography with ECD detector. The recovery varied from 92.1% to 95.3% and the relative standard derivation ranged from 2.2% to 8.9%. The limits of detection was 8μg/kg. This method could satisfy the demand of analysis of brominated flame retardants in plastics.The sixth chapter, using a low-grade Ca-bentonite produced from Longyan city, Fujian province as raw material, the test of Na-modification by suspensoid was carried out. Main technical conditions for the modification of Ca-bentonite such as modifying agent types and its dosage, pulp density and agitating time were discussed. The best reaction conditions are as following: the conversion agent is NaF; its dosage is 4.2%; pulp density is 10%; conversion time is 90 min; conversion temperature is 70℃. The bentonite with high V_B of 33.5 mL/g and high CEC of 114.0 mmol/100g could obtained at the best experiment conditions. X-ray diffraction shows that d (001) is 1.27145 nm; The converted bentonite have been improved the properties to produce high quality organo-bentonite.