Raman Spectrum Applied To Analysis Of RhB In Chilli Products And Peanut Oil Adulterated With Trench Oil

Recent years, frequent appearance of food safety problems at home and abroad, has inflicted serious economic loss and social impact, which, however, would pose a serious threat on consumers’health in general. The perfection of sample processing and testing technology may help know the problem in food safety without delay. At present, the lack of effective sample processing and testing technology result in failing to monitor and control of test sample. Thereforce, developing convenient and accurate food sample processing and testing technology is one of the key factors to guarantee food safety.Rhodamine B is potentially carcinogenic, teratogenic and mutagenic, which has been monitored for the safety of food per government regulations. For the time being, main detection methods of rhodamine B are liquid chromatography and liquid chromatography tandem mass spectrometry. And the main pre-treatment methods of rhodamine B sample in practice are liquid-liquid extraction and solid phase extraction. The detection and treatment process are complicated, which require expensive equipments and a variety of organic solvents.Hogwash oil may greatly harm people’s healthy, due to its complex ingredient, such as BaP, many dimers and trimers, especially to children and pregnant women. The common detection methods are gas chromatography and gas chromatography tandem mass spectrometry, whigh need large-scale and expensive instruments.With the emergence of laser technique, Raman spectroscopy has made very good progress in analytical chemistry and other fields. Compared with other measurement, the method is simple and quick. However, surface enhance Raman scatting is a new sensitive quantitative analytical technique which has been developed recently and been applied widely in the study of life and nanometer materials etc. Matrix solid phase dispersion is a simple way of sample preparation, which is applicable to most of the samples. At present, it has also been applied widely to the study of environmental, food and biological samples. In this thesis, tentative study to make Raman spectroscopy be applied in the food safety testing to detect the illegal additives RhB in chilli products and illegal cooking oil for establishing a sensitive, selective, simple and rapid new method to further expand the scope of Raman spectroscopy application. The (?) research contents and conclusions are presented as follows:1. The best condition of surface enhanced Raman spectroscopy was explored by uing single factor experiment to investigate pH, NaCl concentration, adding sequence, and three kinds of liquid ratio in the reaction system. The obtained optimized detection conditions are as follows:0.55M NaCl solution and rhodamine B aqueous solution were added to the colloid (pH=3), the proportion of the three kinds of liquid is100:100:400. Under these conditions detection limit of standard aqueous solution of rhodamine B was1×10-4mg/mL.2. The best condition of matrix solid phase dispersion has been studied by using orthogonal design to investigate dispersant type, the proportion of dispersing agent and samples, eluent type, and dosage of eluent. The result indicates that the optimum conditions for extracting Rhodamine B from chili powder were as follows:dispersant type was silica gel, ratio of dispersing agent and sample was1:1, composition of the eluent was80%of acetonitrile, and elute volume was20mL; and that the optimum conditions for extracting Rhodamine B from pepper oil were as follows:dispersant type was neutral aluminum oxide, ratio of dispersing agent and sample was2:1, composition of the eluent was80%of methanol, elute volume was20mL; and that the optimum conditions for extracting Rhodamine B from chili paste were as follows:dispersant type was neutral aluminum oxide, ratio of dispersing agent and sample was3:1, composition of the eluent was80%of acetonitrile, and elute volume was5mL. Under this condition, recovery rate of these three pepper products was from80.6%to100.8%with a RSD from1.4to4.0.3. Quantitative detection of rhodamine B in chilli products fas been established based on the above results. The RhB in chili powder detection limit was10μg/g, the linear range was10-100μg/g; linear correlation coefficient was0.9912, and relative standard deviation was1.1%-4.7%. The RhB in pepper oil detection limit was5μg/g, the linear range was10-100μg/g, linear correlation coefficient was0.996, and relative standard deviation was1.5%-5.3%. The RhB in chili paste detection limit was5μg/g, the linear range was10-100μg/g, linear correlation coefficient was0.9945, and relative standard deviation was1.7%-4.9%.4. A high efficient and rapid detection of adulterated peanut oil has been established by application of Raman spectra. This method distinguish high quality peanut oil and adulterated peanut oil with obvious difference. Compared with other traditional measurement of hogwash oil, this method is simple and quick with an ability to detect the peanut oil adulterated with as low as mixed10%hogwash oil.The results of using Raman spectroscopy technology to detect rhodamine B in chilli products and the peanut oil mixed with hogwash oil are relatively ideal with certain promotion significance of reality. There is no doubt that Raman spectroscopy can be applied in the testing of food safety.