Study On Analysis Method Of Selenium In Rice And Analysis Of Hangzhou Local Rice Products Of Selenium

In this paper, the local market were collected in selenium rich rice, local grain reserve(including the level of Hangzhou, Xiaoshan, Yuhang, Fuyang, Jiande, Tonglu, Ling’an and Chunan 7 county-level city) and local food processing enterprises of rice and rice a total of 197 batches, according to Binhai County Zhenghong plastic factory production of steel F4 high pressure digestion tank combined with atomic fluorescence spectrometer of selenium in the region in the grain is analyzed and the morphology of the Total Selenium rice.The factory production of high pressure digestion is currently digestion of solid and liquid complex matrix dissolution method, through closed to generate high pressure, so that the relatively low temperature to prevent the sample dissolved metallic elements, volatile, with classic open wet digestion compared with samples, complete decomposition, acid dosage, the blank value control, volatile elements are not easy to damage and prevent environmental pollution and other advantages, at the same time, microwave and compared with a sample volume, high detection limits of features.Limited general for the 0.04mg/kg- 0.3mg/kg, in low content of area, commonly used methods include"GB5009.93-2010 "the national food safety standards of selenium in foods determination", by wet digestion method open, the content of selenium in the actual detection of rice and rice in the volatile, spills, the detection limit is high, and because the digestion blank not good quantitative control, so the poor reproducibility, low for rice content(less than 0.1mg/kg) is very difficult to determine the exact numerical, and this method does not provide a detection method of inorganic selenium; dry digestion also exist at high temperature carbonation loss, incomplete and other issues, the recovery of standard addition samples and its the not ideal, the other is currently more expensive domestic microwave digestion pretreatment equipment, with a digestion speed, blank model, but because the sample weight limit, detection limits for selenium low content is not very ideal, with the increase of sample amount of easy to produce explosive boiling and other dangerous, serious impact on the laboratory and the safety of personnel. The method is the use of the steel liner F4 digestion digestion sample weight up to 1.25 g, to avoid the volatilization of metal elements, complete digestion, blank value controllable, steel liner outer jar strong guarantee the safety.atomic fluorescence spectrometer parameters optimization method, the minimum detection limit is 0.007mg/kg, the recovery rate was 90-110% standard and national standard substance, using GSB-1 and GSB-23 with low content of selenium in quantitative, results in the standard range, meet the low content of selenium rich rice detection decision. At the same time using hydrochloric acid extraction of inorganic selenium was extracted, studied in grain starch material for specific interference selenium absorption, compared the different acidity, temperature, time effect on the extraction of the shape, and then high pressure digestion to destroy the selenium and starch material bonding, recovering verification using national standard material of rice, satisfactory accuracy and precision. Results: 20 batches of selenium rich rice grain on the market counterfeit serious content, most of the discrepancies, the coincidence rate was 60%, the coincidence rate of organic selenium 35%; Hangzhou local range and 7 districts and counties to grow food in 109 batches, organic selenium coincidence rate was 24%; the rice enterprise and the turnover of grain of rice production in the region, including analysis of 66 samples batch, 18 batches of total selenium meet, but only 3 batch detection of organic selenium in accordance with the product, only 4.55% of the total. Conclusion: it is necessary to strengthen supervision, issued national standards related to selenium content as soon as possible. Selenium content in brown rice is more than white rice made after intake, eat brown rice beneficial to the selenium absorption.