扩散-离子色谱法测定鱼肉中氟的含量

采用并改进国标GB/T 5009．18-2003中扩散复色法测定食品中氟的前处理步骤,用离子色谱法取代国标中的测定方法,建立扩散-离子色谱法测定鱼肉中氟含量的新方法。用自制电化学中和器降低了试液中的pH值,使试液适于用离子色谱法测定。采用外标法定量,氟标准溶液的质量浓度与其离子色谱的峰高在0．04～5．00mg/L的范围内有良好的线性关系,相关系数为0．9980。在1．00mg/L和2．00mg/L两种浓度下的平均加标回收率分别为94．00%、98．00%。日内精密度和日间精密度分别为3．93%、2．78%。定性检测限和定量检测限分别为1．58、5．25μg/L。该方法可望用于其它生物样品中微量氟含量的测定。

Determination of Fluorine in Fish by Diffusion-ion Chromatography

Adopting and improving the pretxeatment of determination of fluorine in foods with diffusion-spectrophotometery in the national standard,the method for determination was replaced by ion chromatography,so a new method for determinating the fluorine in fish by diffusion-ion chromatography was developed.The pH value of the solution was reduced by a home-made electrochemical neutralizer.The solution was then fit to be determinated by ion chromatography.There is linear correlationship between the mass concentration(mg/L)and peak height(nS)of the fluorine,with the coefficient of 0.9980.The detection range is 0.04～5.00 mg/L.The average recoveries of two spiked samples with 1.00,2.00 mg/L are 94.00%,98.00% respectively,and the within-day and between-day precisions are 3.93%,2.78% respectively.Limit of detection and limit of quantification are 1.58,5.25μg/L,respectively.This method would be expected to be used for the determination of micro fluorine in other biological samples.