奶粉中钠、钾、镁、钙的“动态透析”离子色谱法测定研究

Study on Dynamic Dialyzing Ion Chromatography Determination of Sodium,Potassium,Magnesium and Calcium in Milk Powder

目的:探索出较为简便易行的奶粉中钠、钾、镁、钙同时测定的方法。方法:使用透析袋将溶解后的奶粉透析后取出分别过C18柱分离后使用20mol/L甲烷磺酸作为淋洗液,用离子色谱法同时分离和测定奶粉中钠、钾、镁、钙这四种物质。结果:选择转速为200r/min室温下动态透析平衡时间只要2h左右,四物质离子色谱峰形较好,其他离子对它的干扰较小,RSD%均小于5%,回收率在95%～105%之间。结论:奶粉中钠、钾、镁、钙的"动态透析"离子色谱法测定是一种较为实用的测定方法。

Objective： To explore a simple and practicable ion chromatography method for simultaneous determination of sodium, potassium, magnesium and calcium in milk powder. Methods： After being dialyzed, milk powder solution passed through C18 column, and then the sodium, potassium, magnesium and calcium in the effluent was simultaneously detected with 20 mmol/L CH3SO3H as eluent. Results： The dynamic balance period is only two hours or so at the stirring speed of 200 r/min and room temperature. The peak shapes of the four ions are perfect without big disturbance. Their relative standard deviations are all below 5% and their average recovery rates are all between 95 % and 105%. Conclusion： Ion chromatography is suitable to the simultaneous determination of sodium, potassium, magnesium and calcium in milk powder.