离子色谱法测定水产品中甲醛次硫酸氢钠含量
IC Determination of Formaldehyde Sodium Bisulfoxylate in Aquatic Products
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摘要: 提出了离子色谱法测定水产品中甲醛次硫酸氢钠残留量的方法。样品经0.01 mol·L-1氢氧化钠溶液超声浸取,先后经C18固相萃取柱和IC-Ag固相萃取柱净化,萃取液以AS-11(250 mm×4 mm)为分析柱,不同浓度的氢氧化钾溶液梯度洗脱分离并用抑制型电导检测器测定甲醛次硫酸氢钠含量。甲醛次硫酸氢钠的质量分数在0.1~100 mg·kg-1范围内与对应的峰面积呈线性关系,方法的检出限(3S/N)为0.05 mg·kg-1。方法用于分析3种水产品样品,加标回收率在94.2%~103%之间,测定值的相对标准偏差(n=5)在2.4%~3.8%之间。Abstract: A method of IC for the determination of residual amount of formaldehyde sodium bisulfoxylate in aquatic products was proposed. The sample was extracted ultrasonically with 0.01 mol·L-1 NaOH solution and the extract was purified by passing through C18 and IC-Ag solid phase extraction columns. The extract was separated on AS 11 (250 mm×4 mm) column with KOH solution of different concentrations as mobile phase in gradient elution and detected by inhibitory conductivity detector. Linear relationship between values of peak area and mass fraction of formaldehyde sodium bisulfoxylate was kept in the range of 0.1-100 mg·kg-1, with values of detection limit (3S/N) of 0.05 mg·kg-1. The present method was used in the analysis of 3 kinds of aquatic products, giving values of recovery ranged from 94.2% to 103%, and RSD′s (n=5) ranged from 2.4%-3.8%.