磁性分离富集-分光光度法测定食品中的诱惑红

Determination of Allura Red in Food by Spectrophotometry with Magnetic Separation and Concentration

建立了分光光度法测定食品中痕量诱惑红的磁性分离富集新体系。对定量分离分析诱惑红条件,如pH值、吸附剂用量、吸附时间、诱惑红的初始浓度及体积和干扰离子等进行了研究。结果表明,在最佳条件下,Fe_3O_4纳米粒子对诱惑红的饱和吸附量为16.9mg/g,吸附常数为17.4L/mg,吸附率达到98.5%,吸附过程以静电吸引和离子交换为主,以5mL0.6mol/L的KCl为洗脱液,洗脱率达99.5%,富集倍率达到100倍;方法的线性范围为5—600μg/L,检出限为3.9μg/L,相对标准偏差(RSD)为2.4%。该法用于食品中痕量诱惑红的富集和测定,结果令人满意。

A novel system for magnetic separation and concentration of trace allura red from food by spectrophotometry was established.Optimal quantitative analytical conditions including pH？ adsorbent dosage,adsorption time,original concentrations and volumes of allura red and the interference ions were studied.Under the optimal analytical conditions,the maximum adsorption amount,the Langmuir adsorption equilibrium constant and adsorption rate of iron oxide on allura red were respectively 16.9mg/g,17.4 L/mg and 98.5%,and there were electrostatic attraction and ion exchange in adsorption process.The adsorbed allura red could be eluted by 5 mL KC1 of 0.6mol/L, and the elution percentage reached 99.5%.Preconcentration factor was found as 100.The linear range of method was in the range 5-600ng/mL.The detection limit was 3.9μg/L with relative standard deviation（RSD） of 2.4%.The method is applied to concentrating and determining trace allura red in food with satisfactory results.