摘要
研究了一种离子色谱柱后衍生直接光度法测定食品中含硫阴离子化合物.采用IonPacAS22A分析柱(250mm×4mm),IonPacAG22A保护柱(50mm×4mm),4.5mmol·L-1碳酸钠和0.8mmol·L-1碳酸氢钠等度淋洗,柱温设为室温,衍生试剂是0.24g·L-1碘液和0.2%磷酸(V︰V)的混合溶液,检测波长为288nm.样品用20mg·L-1草酸溶液萃取,经高速离心、上层清液过C18预处理小柱及0.45μm过滤膜后直接进样.实验结果表明,方法的检测限硫离子、甲醛合次硫酸氢根离子、亚硫酸根离子、硫氰酸根离子及硫代硫酸根离子分别为0.006,0.004,0.006,0.006和0.007mg·L-1.一天之内的相对标准偏差分别为4.86%,3.24%,3.76%,2.68%和2.07%.实际样品测定,除硫离子外,方法的回收率分布在67.2%～116.5%之间,硫离子的回收率为38%～45%.
A novel method for determination of formaldehyde sulfoxylate, sulfide, sulfite, thiocyanate, and thiosulfate in foodstuffs by ion chromatography separation with postcolumn deriviation and direct spectrophotometric detection has been developed. All species are separated at Dionex IonPac AG22A and AS22A with mobile phase of a mixture of 4.5 mmol·L^-1sodium carbonate and 0.8 mmol·L^-1 sodium bicarbonate at a flow-rate of 1.0 mL·min^-1 The postcolumn deriviation solution was 0.24% iodine in 0.2% phosphate acid and the detection wavelength was set at 288 nm. The detection limits （LOD, signal-to-noise ratio of 3） of sulfide, formaldehyde sulfoxylate, sulfite, thiocyanate, thiosulfate, were 0.006, 0.004, 0.006, 0.006, and 0.007 mg·L^-1, respectively. Within-day relative standard deviations （RSD, n=8） of sulfide, formaldehyde sulfoxylate, sulfite, thiocyanate, thiosulfate were 4.86%, 3.24%, 3.76%, 2.68% and 2.07%, respectively. The recoveries of real samples were in the range of 67.2 % to 116.5%, with the exception of sulfide. The recoveries of sulfide were only in the range of 38%---45%.
出处
《中国科学（B辑）》
CSCD
北大核心
2009年第8期819-824,共6页
Science in China(Series B)
基金
国家自然科学基金(批准号:20775070)
浙江省自然科学基金(批准号:Y507252)
浙江省钱江人才计划(批准号:2008R10028)
浙江省分析测试基金(批准号:2007F70061)资助
关键词
柱后衍生
离子色谱
含硫阴离子化合物
postcolumn deriviation, ion chromatography, sulfur-containing inorganic compounds
