线性扫描伏安法测定辣椒制品中苏丹红Ⅰ含量

Linear Scanning Voltammetric Determination of SudanⅠin Chilli Products

基于苏丹红Ⅰ分子中的-C=C-和-N=N-基团的电活性,在悬汞电极上还原产生还原波,其还原峰高与苏丹红的浓度呈线性关系。据此提出用线性扫描伏安法测定辣椒制品中苏丹红Ⅰ的含量。试验中用悬汞电极为工作电极,饱和甘汞电极为参比电极,铂微电极为对电极,饱和硼砂缓冲溶液(pH 9.2)为支持电解质,并以丙酮作为样品的溶剂,记录在-1 050mV处还原峰电流ip。测得苏丹红Ⅰ的质量浓度在0.1~1.4mg·L-1范围内与其峰高呈线性关系,检出限(3s/k)为9.8μg·L-1。用标准加入法进行回收试验,测得回收率在88.0%~98.4%之间,测定值的相对标准偏差(n=5)在0.72%~5.4%之间。

In a buffer medium of saturated borax solution(pH 9.2)acting as supponting electrolyte and using acetone as solvent for samples of chilli products,a reductive wave giving by the electro active-C=C-and-N=N-groups in the molecule of SudanⅠ was observed at the hanging mercury drop electrode which is the working electrode of the 3-electrode system,with SCE as reference electrode and micro-Pt electrode as counter electrode,at the potential of-1 050 mV.Linear relationship between values of reductive peak current ipand mass concentration of SudanⅠ was obtained in the range of 0.1-1.4mg·L-1,and detection limit(3s/k)was found as 9.8μg·L-1.Based on these facts,a linear scanning voltammetric determination of Sudan Ⅰin chill products was proposed.Using samples of chilli sauce as matrixes recovery was tested by standard addition method,giving results of recovery in the range of 88.0%-98.4%.Values of RSD′s(n=5)calculated from the determined results were in the range of 0.72%-5.4%.