扩散-离子色谱法测定鱼肉中氟的含量

Determination of Fluorine in Fish by Diffusion-ion Chromatography

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。

Adopting and improving the pretreatment 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. Them 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, 5.25 μg/L, respectively. This method would be expected to be used for the determination of micro fluorine in other biological samples.