离子色谱法测定奶粉中氯化胆碱、钠、钾、镁、钙的含量

Determination of Choline Chloride,Na^+,K^+, Mg^(2+) and Ca^(2+) in Milk Powder by Ion Chromatography

建立离子色谱定量测定奶粉中钠、钾、氯化胆碱、镁、钙的方法,应用IonPac CS-12A(250 mm×4 mm)阳离子交换柱,淋洗液为20 mmol/L MSA,等浓度淋洗,流速为1.0 mL/min,电导检测器检测,方法检出限为0.5～10 mg/kg。6次测定平行样,相对标准偏差2.3%～4.7%,5种阳离子加标回收率74.7%～93.5%,该方法具有准确、操作简便等特点,可用于奶粉中钠、钾、氯化胆碱、镁、钙的检测。

A method was established to determine choline chloride,Na＋,K＋,Mg2＋ and Ca2＋ in milk powder by using ion exchange chromatography with conductivity detector.The samples were separated on a IonPac CS-12A（250mm×4 mm） cation exchange column using gradient elution of MSA,and the velocity was 1.0 mL/min.The detection limit of the method was 0.5~10 mg/L.The relative standard deviation of this method is 2.3%-4.7%（n=6）and the recovery is the range of 74.7%~93.5%.The method is accurate and simple,and is suitable for rapid detection choline chloride,Na＋,K＋,Mg2＋ and Ca2＋in milk powder.