酶标法测定原料乳中硫氰酸根含量

Determination of thiocyanate radical content in raw milk by enzyme labelling method

目的建立酶标法测定原料乳中硫氰酸根含量的分析方法。方法用三氯乙酸溶液沉淀原料乳中蛋白质和脂肪,定量滤纸过滤后取上清液,硫氰酸根与硝酸铁溶液显色后,用酶标仪在450nm波长处测吸光度值,用原料乳做标准曲线,定量测定原料乳中硫氰酸根的含量。结果硫氰酸根浓度在0～16mg/kg线性关系良好,相关系数r=0.9991,方法回收率在95.75%～102.83%之间, RSD≤3.25%,检出限为0.54 mg/L。结论本研究的检测方法数据可信度高,操作简便,一次性上机读取吸光度值,节约检测时间,测定成本相对较低,适用于批量性检测生乳中硫氰酸根的定量分析。

Objective To establish a method for the determination of thiocyanate radical content in raw milk by enzyme labelling method. Methods The protein and fat in raw milk were precipitated by trichloroacetic acid solution, the supernatant was filtered by quantitative filter paper, and the absorbance of thiocyanate radical and ferric nitrate solution was measured at 450 nm by enzyme labeling instrument. The content of thiocyanate radical in raw milk was determined by standard curve. Results Thiocyanate radical had good linear relationships in the range of 0~16 mg/kg, and the correlation coefficients was 0.9991. The recoveries were 95.75%-102.83%, with the relative standard deviations of less than 3.25%. The limit of detection was 0.54 mg/L. Conclusion This method has the advantage of high reliability, simple operation, one-off reading absorbance value, saving detection time and relatively low cost, which is suitable for quantitative analysis of thiohydric acid in raw milk.