摘要
采用顶空气相色谱法间接测定了羧甲基壳聚糖中氯乙酸的残留量。样品(0.2g)于顶空瓶中超声溶解在水3mL中,加入甲醇2.5mL,硫酸1.5mL,在70℃水浴反应40min使之酯化。按顶空条件进样,用HP-INNOWAX毛细管色谱柱分离,氢火焰离子化检测器测定。分别选择15min和85℃作为样品在顶空瓶中的平衡时间和平衡温度。氯乙酸的质量在0.2～20mg范围内与其峰面积呈线性关系,方法的检出限(3S/N)为5.6mg·L-1。方法用于实样中氯乙酸的测定,用标准加入法做回收试验,测得回收率在90.0%～92.0%之间,测定值的相对标准偏差(n=5)在0.7%～0.9%之间。
Residual chloroacetie acid was indirectly determined by head-space GC. The sample （0. 2 g） was dissolved ultrasonically with 3 mL of H20 in a head-space flask, and the solution was esterified at 70 ℃ in a water bath for 40 min by reacting with 2.5 mL of methanol and 1.5 mL of sulfuric acid. The sample was introduced under the head-space condition. The gaseous analyte was separated on HP-INNOWAX capillary chromatographic column, and determined by hydrogen FID. The time and temperature chosen for equilibration of the sample in head space flask were 15 min and 85 ℃ respectively. Linear relationship between values of peak area and mass of chloroacetic acid was obtained in the range of 0. 2-20 mg, with detection limit （3S/N） of 5.6 mg · L ^-1. The proposed method was applied to the determination of chloroacetic acid in substantial samples. Recovery was tested by standard addition method, giving values of recovery and RSD＇s （n=5） in the ranges of 90. 0%-92. 0% and 0. 7%-0. 9%.
出处
《理化检验（化学分册）》
CAS
CSCD
北大核心
2012年第2期144-146,149,共4页
Physical Testing and Chemical Analysis(Part B:Chemical Analysis)
基金
河北师范大学应用开发基金(L2
009Y12)
