Study On Detection Technology Of Several Illegal Additives In Rice And Soybean Products

Adding non-edible substances and abusing food additives illegally in food production and management have become a prominent problem in China’s food safety, which cause serious damage to people’s health. Adding dyes and methenamine to soybean and rice products lacks of relevant national standards and detecting methods. Detecting methods of basic orange and basic flavine O are also has disadvantages of low efficiency and time consuming. The high performance liquid chromatography(HPLC) wavelength program method can achieve the purpose of detection of four basic dyes at the same time. The detection method of methenamine is its residues or formaldehyde content, but it cannot detect its total content, thus establish the detecting method of methenamine total content in rice and soybean products.This paper establishes the high performance liquid chromatography(HPLC) wavelength program method to detecting of basic dyes in soybean products and methenamine total content in rice and soybean products. Optimize by establish the chromatography conditions to draw the standard curve. Establish the pre-process method of the target and optimize. The method is evaluated by precision, accuracy, the limit of detection and limit of quantification.(1) To establish the HPLC wavelength program method to detect the basic orange and the basic flavine O in non-fermentation of soy products. Results show that the determined ethanol is confirmed as extraction solvent, pH value of mobile phase is 4.00, wavelength program is 0.000 min to 6.000 min(basic orange 2, 448 nm), 6.000 min to 7.000 min(basic flavine O, 430 nm),after 7.000 min(basic orange 21, basic orange 22, 494 nm). And t the accuracy and precision of method is evaluated, results show that standard curve linear relationship is good, the correlation coefficient(R2) was higher than 0.9990, the limit of detection and the limit of quantitation meet the requirements of detection.(2) Methenamine total content detection method in rice and soybean products is created by using the HPLC wavelength program method, detection of the methenamine not convert and formaldehyde-2,4-dinitrobenzene hydrazone content by methenamine has transformed derivatives. The results show that the ultrasonic extraction effect is better; derivative reaction conditions for temperature are 60℃, the time arranges for 30 min, pH is 4.50; gradient elution program: 0.000~4.000 min(100% mobile phase A), 4.000~12.000 min(50% mobile phase A +50% mobile phase B), can shorten the retention time and improve the peak type, at the same time set the wavelength program for 0.000~4.000 min(methenamine,210 nm), 4.000~12.00 min formaldehyde-2,4-dinitrobenzene hydrazone,351 nm). And the accuracy and precision of method is evaluated, results show that standard curve linear relationship is good, the correlation coefficient(R2)was higher than 0.9998, the limit of detection and the limit of quantitation meet the demand of detection.This paper uses HPLC wavelength program method to detect basic orange and basic flavine O method in non-fermented soy products to improve the detecting efficiency, save time and experimental resources. The detection method of the total amount of methenamine in rice products is created, which provides the theory basis of comprehensive detecting methenamine in rice and soybean products or other food.