Process for preparing copolyester soybean esterase

Abstract

The invention discloses a preparation method of soybean esterase used for the determination of pesticide residues in fruits and vegetables. The steps include: selecting high-quality soybeans, crushing, extracting with phosphate buffer solution, differential centrifugation, ammonium sulfate salting out and precipitation, ion exchange chromatography purification and freeze-drying. The preparation process of the invention is simple and stable, and the production cost is lower than the production cost of extracting pure enzyme products of acetylcholinesterase. The sensitivity of the soybean esterase purified by the invention is more than 19 times higher than that of the enzyme crude extract. The lowest detection limit (LDC) of monocrotophos, methamidophos, parathion, chlorpyrifos, dimethoate, malathion, trichlorfon and other pesticides can reach 0.03125ppm, and the LDC of chlorpyrifos and chlorpyrifos Even reached one thirty-second of its maximum residue limit (MRL), and the LDCs of parathion, parathion, thionon, etc. also reached one sixteenth of its MRL. The soybean esterase prepared by the invention can fully satisfy the rapid detection of various organophosphorus pesticide residues, and can be widely used as an enzyme marker for various methods of rapid detection of pesticide residues.

Description

technical field

[0001] The invention relates to a method for detecting pesticide residues, in particular to a method for preparing soybean esterase for rapid detection of organic phosphorus and carbamate pesticide residues in fruits and vegetables. Background technique

[0002] At present, organophosphorus pesticides and carbamate pesticides are still widely used in agricultural production, and they are very easy to cause residues in agricultural products, especially in fruits and vegetables, which are more prominent, causing harm to human health. Therefore, pesticide residues are important detection and control indicators for food quality and safety. In recent years, there have been many studies on rapid detection methods for pesticide residues. Among them, "enzyme inhibition-spectrophotometry" has been widely used because of its sensitivity, simplicity and speed, and has been listed as a national recommended standard (GB / T5009.199- 2003). The enzyme inhibition method is ...