离子色谱法测定乳品中硫氰酸钠含量

采用离子色谱法测定乳品中硫氰酸钠的含量。样品用5 mL乙腈沉淀蛋白质,上清液过C18柱净化,所得的产物采用离子色谱法测定,外标法定量。结果表明,通过流动相以及前处理方法的改进,硫氰酸钠质量浓度在0.10~4.00 mg/L范围内与色谱峰面积呈良好的线性,相关系数r2=1,方法的检出限为0.01 mg/L。在牛奶样品中加入硫氰酸钠标准溶液进行回收试验,测得回收率为95.0%~101.0%,测定结果的相对标准准偏差为1.8%~2.8%(n=7)。该方法操作简便,能有效避免假阳性的发生,测定结果准确,适合于乳品中硫氰酸钠的检测。

Determination of Sodium Thiocyanate Content in Milk by Ion Chromatography

Ion chromatography was applied to the determination of sodium thiocyanate content in milk. The sample was purified by protein precipitation and the C18 extraction column. Then the product was tested by ion chromatography and the concentration was quantified by external standard method. Through the improment of mobile phase and pretreatment method,the concentration of sodium thiocyanate was linear with peak area in the range of 0.10–4.00 mg/L,and the correlation coefficient was r2=1. The detection limit determination of the method was 0.01 mg/L. Test recovery experiment was made by standard addition method,and the recovery was 95.0%–101.0%. The relative standard deviation of the determination results was 1.8%–2.8% （n=7）. This method has the advantages of simple operation,it can effectively avoid the occurrence of false positive so it is suitable for detection of sodium thiocyanate in milk.