高效液相色谱法测定牛奶中双乙酸钠

建立了牛奶中双乙酸钠的快速测定方法,为执法提供技术支持。牛奶样品用水提取,加入硫酸锌溶液(0.5 mol/L)和氢氧化钾溶液(0.5 mol/L)沉淀、超声、离心,用C18柱分离,二极管阵列检测器测定,外标法定量。色谱条件:Agilent TC-C18色谱柱,流动相为质量浓度1.5 g/L磷酸氢二铵溶液与甲醇体积比为90:10,流速1mL/min。线性范围10～500μg/mL,相关系数R~2=0.99957,定量检测限50 mg/kg,空白样品添加50,100,500μg/mL 3个水平,回收率为101.12%～103.68%,相对标准偏差为2.01%～3.93%(n=6),说明方法准确可靠。

Determination of Sodium Diacetate in Milk by High performance Liquid Chromatography

A rapid determination method for sodium diacetate in milk is established to provide technical support for law enforcement.The milk samples are extracted with water,adding zinc sulfate solution(0.5 mol/L),and potassium hydroxide solution(0.5 mol/L).After precipitation,ultrasonic,centrifugation,then separated with a C18 column,determined by DAD detector and quantified by external standard.Chromatographic conditions:the Agilent TC-C18 column,mobile phase is 1.5 g/L of diammonium phosphate solution:methanol is 90:10,flow rate is 1 mL/min.Experimental linear range is 10-500μg/mL; correlation coefficient R~2=0.999 57,quantitative detection limit is 50 mg/kg.Adding 50,100 and 500μg/mL levels to a blank sample,recoveries of 101.12%-103.68%and relative standard deviation in the range of 2.01%-3.93%(n=6) are finally gotten.This method is accurate and reliable for determination for sodium diacetate in milk.