Detection Of Sulfur Dioxide In Food

Sulfur dioxide,as an additive,is often used in food,which is usually used to prevent food spoilage,improve food preservation,bleach food,etc.However,excessive addition and illegal addition will lead to a large amount of residues in the human body and cause great harm to the human body.Therefore,for the detection of additives is also becoming more and more important,the so 2 detection methods in use today,the test time is longer,is different with the operator according to the experiment error is bigger,so this paper established a kind of sulfur dioxide in food yan before new derivative-HPLC fluorescence detection method,the results are as follows:1.Determination of derivative reaction methods:Derivative reagents such as o-phthalaldehyde and ammonium acetate were selected to react with sodium sulfite to generate 1-sulfonyl-isoindole compounds,which had fluorescence characteristics.Based on the chemical reaction mechanism of the compounds,the software Scan wavelength in the fluorescence spectrophotometer was used to Scan the wavelength of the derived compounds.The results show that the maximum excitation wavelength is 323nm and the maximum emission wavelength is 386nm.Under this wavelength,the conditions of the derivation reaction were optimized,including the temperature of derivation,the time of derivation,and the p H value of the buffer solution.The single factor and orthogonal test were used to optimize the reaction conditions,and finally the conditions were determined.That is,reaction temperature:50?;Reaction time:5min;The p H value of buffer solution was 5.5,and the maximum fluorescence intensity value was obtained under this test condition.2.Analysis and determination by liquid chromatography:Firstly,the target compound 1-sulfonyl-isoindole was separated,and the liquid chromatography conditions were optimized to determine the best detection scheme.Then,a series of verification tests were carried out for the method,and the actual samples were detected by the established method.According to the test results of the standard curve,when the linear range of the compound was 0-10?g/mL,its concentration showed a good linear relationship with the amount of the corresponding standard solution,the correlation coefficient R~2=0.995;The recoveries,limits of detection and limits of quantification of three different supplemental levels were determined.The results showed that the recoveries were in the range of 82.32%?105.08%.Minimum detection limit:0.2ug/mL,limit of quantification:0.7ug/mL;According to the experimental situation,the matrix effect was evaluated,and it was found that the dried fruits in food had a relative inhibitory effect on the detection results.At the same time,the accuracy of the experiment was investigated.The analysis results showed that the accuracy of the experiment was between 0.2% and 2.89%,and the precision of the experiment was between 1.47% and 4.11%,and the relative standard deviations were all less than 10%.In addition,the results of the stability inspection show that the error of the measured results within 10h is small.According to the results of methodology verification,it can be seen that the method established in this study is suitable for the study of the detection of sulfur dioxide in food.3.The derivation method established in the above experiment was used to optimize the mass concentration of sodium hydroxide in the pretreatment extract,and the optimal extraction mass concentration was determined to be 0.04%mol/L.Testing analysis of 14 kinds of samples,including fungus mushrooms(dried black fungus,mushrooms,dried fruits(lemon dry dry,dry dried mango,pineapple,peach,Jiang Gan)nuts,class(melon seeds,pine nut,almond,walnut)and squid,brown sugar,ginger,such as samples,and compared with national standard method of titration analysis.The detection results of the method established in this test show that the detection range is between 0.0019-0.0312g/kg,and the titration method is between 2.11-3.48g/kg.The detection range of the food detected by this method is lower and wider.In addition,the experimental operation is simple,the experimental process takes a short time,and has a strong fluorescence properties.