Method for determining pesticide residues on grains

Abstract

The invention discloses a method for determining pesticide residues on grains. The method comprises the following steps: step a, a grain sample is obtained through ultrasonic extraction; step b, 2-4 g of sample fragments are added to a centrifuge tube containing hydroquinone and sodium thiosulfate, then an acetic acid acetonitrile solution is added, and the mixture is oscillated vigorously and subjected to ultrasonic extraction and centrifugation; step c, an acetonitrile extracting solution obtained after centrifugation is fed into a centrifuge tube containing 1-3 g of a cleaning agent, the centrifuge tube is placed on an oscillator, oscillated for 3 min and left to stand for 3 min, an upper solution is absorbed and transferred into a syringe filter directly, suspended solids in the solution are removed through filtering, and a filtrate is collected in a test tube; step d, the test tube filled with the filtrate is placed in a water bath at the temperature of 38 DEG C. The sample is extracted with an ultrasonic technology, so that a large amount of flesh is prevented effectively from being brought in during determination, and the determining accuracy is high.

Description

technical field [0001] The invention relates to a detection method, in particular to a detection method for pesticide residues on grain. Background technique [0002] The problem of pesticide residues in agricultural products is the main obstacle hindering the development of my country's agriculture and the quality and safety of agricultural products. One of the key links to control the amount of pesticide residues in agricultural products is to analyze and detect the amount of pesticide residues in a timely and accurate manner, so as to monitor the rational use of pesticides and eliminate pesticides at the same time. Products with excess residues are on the market. Regardless of whether it is a simple, economical, real-time on-site rapid detection or a routine detection of large instruments in the laboratory, the first step is to divide and prepare the sample. The detection and analysis of pesticide residues requires accurate sampling of agricultural product samples. Sampli...

AI Technical Summary

Problems solved by technology

However, for the food of agricultural products, the penetration of pesticides is hierarchical, and the residual status of different parts such as pulp and peel is quite different. Most of the residual pesticides in the sampling samples mainly exist in the epidermis. In the prior art, the sampling samples are taken from the whole fruit The introduction of a large amount of pulp in the method will inevitably dilute the pesticide residue content of the skin, and some complex components in the pulp will interfere with the detection to a certain extent, which will greatly increase the sampling error and reduce the accuracy of the detection