原料奶中5种阴离子的离子色谱分析

Determination of five kinds of anion in raw milk by ion chromatography

为了建立原料奶中5种阴离子(Cl-,NO3-,HPO42-,SO42-,SCN-)的离子色谱检测方法,将原料奶经乙腈沉淀蛋白质后离心过滤处理进行离子色谱检测.色谱条件,淋洗液:NaHCO3(1.0mmol/L),Na2CO3(3.2mmol/L),体积分数为15%的丙酮超纯水混合液.流速为1.0mL/min,检测器为电导检测器.该方法对5种离子的电导检出限均为0.02mg/L.在线性范围内r=0.997 6及以上.5种离子的精密度RSD为0.08%～9.58%,各阴离子的回收率均为80%～120%,变异系数在10%以内.该方法具有方便、准确、成本低的优点.

A new method was established for determination of five kinds of anion（Cl-,NO3-,HPO42-,SO42-,SCN-）in raw milk by ion chromatography.The method was adopted with sodium bicarbonate（1.0 mmol/L）,sodium carbonate（3.2 mmol/L）and 15% acetone aqueous（volume fraction） as the eluent.The flow rate was 1.0 mL/min.The detection was performed by a conductivity detection mode.The lowest detection limit of five kinds of anion in raw milk was 0.02 mg/L.In linear range r=0.997 6 or above.Precision test RSD was 0.08%-9.58%.The recovery rate was in 80%-120% range.The coefficient of variation was in less than 10%.This method is simple,accurate and suitable for the determination of five kinds of anion in raw milk.