Study On Optimizing Application Of Rapid Detection Methods For Highly Toxic Rodenticides And Cyanide In Fruits And Vegetables

Tetramine,fluoroacetamide and cyanide are the key screening poisons in food security with characteristics of high toxicity and easy access as common toxic chemicals.However,the quality of the products for rapid detection of these poisons is not uniform at present,which makes the accuracy of the test results difficult to be guaranteed.And there are many problems in the rapid detection products,such as unclear extraction methods of toxicants and poor effect of removing pigments from some food materials.In this paper,the extraction methods of tetramine,fluoroacetamide and cyanide for rapid detection of fruits and vegetables were optimized.The sensitivity,specificity,false-positive rate,false-negative rate and applicability of different quicktest products in the detection of fruit and vegetable samples were investigated.At the same time,the overall evaluation of the products was carried out and 10 kinds of products were selected and tested in the simulated food poisoning experiment finally.The results of the experiment are as follows:1.The extraction method of tetramine from fruits and vegetables with organic reagent was optimized.When the sample size of fruits and vegetables was 2 g,4 mL ethyl acetate was used as extraction solvent and filtered by a column containing 0.5 g activated carbon.After about 2 mL filtrate was obtained,ethyl acetate was dried by nitrogen blowing(60℃).This method can obtain a good recovery rate for the extraction of tetramine from food and has a good adsorption effect on pigments.The results have shown that three kinds of tetramine rapid detection products have high sensitivity(all up to 100%),good accuracy(accuracy over 95%)and strong applicability by testing the fruits and vegetables with the concentration of tetramine of 5.0 and 10.0 μg/g.2.The extraction method of fluoroacetamide from fruits and vegetables was optimized Using 4 mL water as extracting solvent and filtered by a column containing 0.5 g activated carbon,the fluoroacetamide had a good recovery rate with perfect adsorption effect on the pigments,when the sample of fruits and vegetables was 2 g.The filtrate obtained could be directly detected by various quick-detection products.The detection of fruits and vegetables with fluoroacetamide concentration of 50.0 and 100.0 μg/g has shown that four kinds of fluoroacetamide rapid detection products have high sensitivity(all up to 100%),good accuracy(over 94%)and strong applicability.3.The extraction method of cyanide from fruits and vegetables was optimized.Cyanide was extracted by adding deionized water according to the mass ratio of fruit and vegetable samples to water of 1:2 and filtered by a column containing 0.5 g activated carbon.After that,the detection rate of cyanide was high and the pigments were well adsorbed.Through the detection of fruits and vegetables with potassium cyanide concentration of 1.0 and 2.0 μg/g,it has been found that three kinds of cyanide rapid detection products have high sensitivity(all up to 100%),good accuracy(all up to 100%)and strong applicability.4.The detection of fresh fruits and vegetables in food security was simulated.When the concentration of tetramine,fluoroacetamide and cyanide in fruits and vegetables was 50.0 μg/g,all the corresponding poisons could be detected with 100% sensitivity.Among them,the tetramine and fluoroacetamide rapid detection products were false positive.In practical work,further instrument analysis is needed to confirm the positive results in laboratory.The 10 kinds of selected products can accurately screen all the poisoned food and meet the needs of food security work.It is recommended that these 10 products be used in food security work.