牛奶与乳饮料中痕量亚硝酸盐的快速荧光检测法

目的 建立牛奶与乳饮料品中痕量亚硝酸盐的快速荧光检测方法。方法 样品经乙醇沉淀蛋白质后,于适量样液中加入L-酪氨酸(L-Tyr),在酸性介质和加热条件下,样液中的亚硝酸盐氧化L-酪氨酸(L-Tyr),在碱性介质中氧化产物可产生很强荧光,标准曲线法定量。结果 方法线性范围为4～40 ng,检出限为0.04mg/kg,相对标准偏差小于10%,加标回收率为87.8%~90.1%。结论 该方法灵敏、准确、快速、分析成本低,适合于牛奶和乳饮料中痕量亚硝酸盐的快速检测。

Determination of trace nitrite in milk and milk beverage by quick fluorescent spectrometry

Objective To establish a quick fluorescent spectrometry for determination of trace nitrite in milk and milk beverage. Methods The protein in sample was precipitated firstly with ethanol and then the nitrite in sample solution reacted with L-tyrosine (L-Tyr) in acidic medium and boiling water both to produce fluorescent product in alkaline medium.The quantification was based on the standard curve method. Results The liner range of the method was 0.4～4 ng/ml,and the detection limit was 0.04 ng/ml with RSDs of less than 10%.The recovery rates of the method ranged from 87.8% to 87.8%. Conclusion The method is sensitive,accurate,quick and inexpensive.It is suitable for the determination of trace nitrite in milk and milk beverage.