液态奶中硫氰酸钠残留的2种快速检测方法优化研究

Optimization of Two Rapid Detection Method for Sodium Thiocyanate Resi⁃due in Liquid Milk

对液态奶中STC残留的两种快速检测方法进行了优化和改进。对UV-VIS方法进行单因素筛选和正交设计优化的结果表明,该方法的检测波长为451 nm,检出限为2.699 mg/L,回收率在93.63%~95.47%之间,RSD为2.21%。目视比色法的操作流程与UV-VIS相比,操作更加简便,时间更短,在一定量牛奶中加入4种常规试剂,待显色反应5 min后直接用溶液颜色与标准比色卡对照判读。若样品溶液颜色比10 mg/L的标准液颜色深,即表明样品中的STC超过规定含量。两种检测方法均具有准确度高、成本低廉,快速便捷的优势,适用于液态奶生产企业和奶牛场现场快速检测。

In this paper,two rapid detection methods for STC residue in liquid milk were optimized and improved.Optimization of UV-VIS method for the detection of STC in milk by single factor and orthogonal design methods showed that selected detection wave⁃length was 451 nm,the limit of detection was 2.699 mg/L,the recovery was ranged between 93.63%-95.47%,and the RSD was 2.21%.Compared with UV-VIS,the operation procedure of visual colorimetry only different from that of crystal violet indicator was added before the chromogenic agent was added.After 5 min of reaction,color of the sample solution was compared with the standard colorimetric card.The sample solution was darker than that of the 10 mg/L solution of standard colorimetric card it indicates that the STC in the sample ex⁃ceeds the specified concentration.Both methods was has the advantages of high accuracy,low cost,fast and convenient,and were suitable for rapid on-site detection in liquid milk production enterprises and dairy farms.