电化学方法快速测定牛奶中的三聚氰胺

摘要

An electrochemical method was developed for the sensitive and selective determination of melamine in milk samples.The sample preparation involved extraction with acetocaustin and clean-up on a solid phase extraction column.The cyclic voltammetry was used to determine melamine in 1.0 mol/L H2SO4 solution,and a strong and stable current of reduction and oxidation peak was observed in the presence of melamine.Under optimal experimental conditions,the glassy carbon electrode（GCE） offered a highly sensitive and rapid response to melamine at the potential of 0.7 V for Ag/AgCl/saturation KCl in 1.0 mol/L H2SO4.The developed method displayed a good linearity over the range of 15-345 mg/kg with a detection limit of 5 mg/kg.The relative standard deviation（RSD） and recovery rate of this method were 3.5%-4.5% and 97.3%-101.2%,respectively.Compared with other reported methods,this method had multiple advantages,such as a broader linear range,a lower detection limit,easier sample pretreatment,quicker determination,lower cost and no requirements for complicated equipments.%建立一种快速测定牛奶中三聚氰胺的电化学方法。先用三氯乙酸溶解牛奶样品,通过固相萃取提取其中的三聚氰胺。将玻碳电极在含三聚氰胺的牛奶样品提取液中进行循环伏安法扫描,在0.7V左右会出现一对氧化还原峰,此峰电流与三聚氰胺含量在15～345mg/kg的范围内呈线性关系,该方法检测三聚氰胺的检测限为5mg/kg,测定方法的回收率和相对标准偏差分别为97.3%～101.2%和3.5%～4.5%。相对于其他测定方法,此方法的样品预处理过程简单、测定速度快、成本低、不需要复杂的仪器设备。