离子色谱法测定水产品中多聚磷酸盐的含量

采用离子色谱法测定保鲜水产品中焦磷酸钠、三聚磷酸钠和三偏磷酸钠的含量。该方法通过温度控制和快速萃取法阻止多聚磷酸盐降解,用三氯甲烷和乙酸铅溶液沉淀蛋白,用25mmol/L KOH溶液进行梯度淋洗。研究结果显示,3种被测物的检出限分别为3mg/kg、2mg/kg、3mg/kg,线性相关系数r为0.9995～0.9997,回收率为92.7%～101.2%,相对标准偏差小于2%。该检测方法简便、快速、重复性好。

Determination of Polyphosphate in Aquatic Product by Ion Chromatography

The polyphosphate in fresh-keeping aquatic product was determined by ions chromatography.During the detection,the degradation of polyphosphate was prevented by controlling temperature and rapid extraction.The chloroform and lead acetate were used for protein precipitation.The gradient elution of 25mmol/L KOH solution can separate and determine the amount of sodium pyrophosphate,sodium triphosphate and sodium trimetaphosphate.The results showed that the limitation of detection of three compounds were 3mg/kg,2mg/kg and 3mg/kg;the linear relevant factor were from 0.9995 to 0.9997;the recovery were from 92.7% to 101.2%.The detection method was accurate,rapid and reproducible.