小麦酯酶的纯化、冻干及对有机磷农药的检测

Purification、freeze-dry of wheat esterase and the detection of organophosphorus pesticides

该文研究从小麦面粉提取的小麦酯酶粗酶液的纯化、冻干和其有机磷农药的最低检测限。确定了用饱和度为30%和60%的硫酸铵对小麦酯酶粗酶液进行分段盐析,纯化后酶液的比酶活是纯化前的2.4倍;最佳保护剂为5%的聚乙二醇,它不仅可以有效保护纯化后的小麦酯酶在冷冻干燥过程中不失活,而且还具有良好的稳定性;最后确定了冻干小麦酯酶酶粉中敌敌畏、敌百虫、毒死蜱、乐果和辛硫磷等5种有机磷农药最低检测限分别为0.01 mg/kg、0.02 mg/kg、0.05 mg/kg、0.07 mg/kg和0.03 mg/kg,均低于国家规定农药最大残留量,冻干酶粉对敌敌畏灵敏度最佳。

Purification, freeze-dried of wheat esterase crude enzyme solution extracted from wheat flour and the minimum detection limit of organophosphorus pesticides were studied. The saturation of 30% and 60% ammonium sulfate was used to treat the crude enzyme solution by fractional salting out method, specific activity of purified enzyme solution was 2.4 times as much as the crude enzyme solution; optimal protection agent was 5% polyethylene glycol, which not only could effectively keep the purified wheat esterase active in the freeze-drying process, but also had good stability; The results showed that lowest detection limits of the freeze-dried wheat flour esterase enzyme to dichlorvos, trichlorfon chlorpyrifos, dimethoate, phoxim and other five organophosphorus pesticides were 0.01 mg/kg, 0.02 mg/kg, 0.05 mg/kg, 0.07 mg/kg and 0.03 mg/kg, which were less than the state pesticide maximum residue levels and the dichlorvos was the best sensitivity to Lyophilized enzyme powder.