酶抑制法农药残留快速测定仪灵敏度的校准

摘要

用农药残留测定仪在波长412 nm处测定农药吸光度的变化值，根据酶抑制法计算抑制率，抑制率与农药浓度呈正相关。用农药标准物质从低于规定的农药检测下限开始配制一系列标准溶液对仪器进行校准，在抑制率为50%处的浓度即为仪器的灵敏度。对影响校准结果的因素进行分析，该方法校准结果的相对扩展不确定度为4%。%According to the principle of enzyme inhibition method, the pesticide residues were determined at wavelength of 412 nm and the absorbance of the instrument value was used to calculate the inhibition rate, which was positively correlated with concentration. With a certificate of pesticide standard substances to configure a series solution for the calibration of the instrument from the concentration below the detection limit in pesticide regulations, the inhibitory rate of concentration 50%was the sensitivity of the instrument, and the influence of calibration results were analyzed. The relative expanded uncertaiinty of calibration results was 4%.