毛细管区带电泳测定食品中甲醛次硫酸氢钠  

Determination of Sodium Formaldehyde Sulfoxylate in Food by Capillary Zone Electrophoresis

作　　者：刘文叶[1,2] 毋楠[3] 李疆[1] 赵珊[1] 丁晓静[1,2] 杨屹[3] 

机构地区：[1]北京市疾病预防控制中心食物中毒诊断溯源技术北京市重点实验室,北京100013 [2]首都医科大学公共卫生学院,北京100069 [3]北京化工大学理学院,北京100029

出　　处：《分析测试技术与仪器》2015年第3期158-163,共6页Analysis and Testing Technology and Instruments

摘　　要：建立了毛细管区带电泳（CZE）-紫外检测法测定粉丝、挂面、冰糖及腐竹中的甲醛次硫酸氢钠含量的新方法.以Φ75!m＂70 cm（有效长度：60 cm）未涂层熔融石英毛细管为分离柱,50 mmol/L磷酸钠＋10 mmol/L NaOH＋0.5 mmol/L十六烷基三甲基溴化铵（CTAB）＋1 g/L聚乙二醇（PEG）35 000为分离缓冲溶液.详细研究了分离缓冲溶液浓度及pH、PEG 35 000浓度及样品提取溶液对甲醛次硫酸氢钠分离及定量的影响.样品粉碎后,用5mmol/L乙酸溶液提取后离心,上清液经滤膜过滤后直接进样.分离电压为-12 k V,检测波长为214 nm.检出限和定量限分别为4 mg/kg和12 mg/kg,线性范围为15~400 mg/kg,线性相关系数（r）为0.999 1,加标回收率在90.0%~95.6%之间.方法测定了从北京当地超市及农贸市场上采集的4种共计12份食品样品,未发现阳性样品.Sodium formaldehyde sulfoxylate is an illegal food additive and is strictly prohibited in China. However, it is sometimes adulterated in food such as silk noodles, fine dried noodles, crystal sugar and bean curd stick in order to bleach, and improve the texture and antisepsis. To ensure the food safety, a new method for the accurate assay of sodium formaldehyde sulfoxylate in food by capillary zone electrophoresis （CZE） has been developed. An uncoated ~ 75 p.m fused-silica capillary of 70 cm total length （effective length： 60 cm） under a separation voltage of -12 kV was used. The separation buffer consisted of 50 mmol/L of Na3PO4, 10 mmol/L of NaOH, 0.5 mmol/ L of cetyhrimethyl ammonium bromide （CTAB） and 1 g/L of polyethylene glycol （PEG） 35 000. The injection pressure and time were 3. 45 ×10^-3 MPa and 13 s, respectively. The factors such as the separation bufferconcentration and pH, concentration of PEG 35 000 and sample buffer, which affecting the separation and quantitation of sodium formaldehyde sulfoxylate were investigated in detail. The samples were ground into powder, extracted by 5 mmol/L of acetic acid and then centrifuged. The supernatant was directly injected after filtered through 0.45 μm cellulose acetate membrane. The corrected peak areas （Ac） sodium formaldehyde sulfoxylate showed a good linear relationship within the correlation coefficient （r） of 0. 999 1. The limit of detection （LOD） was 4 versus concentrations range from 15 -400 （p, mg/L） of mg/kg with a mg/kg （ S/N = 3 ） and the limit of quantitation （LOQ） was 12 mg/kg （S/N= 10）, respectively. The average recoveries at three spiked levels were in the ranges of 90.0% -95.6% with RSDs all less than 8%. Four food samples （a total of 12） collected from local supermarket and farmer＇ s market were analyzed by the current method. No positive sample was found.

关 键 词：甲醛次硫酸氢钠 食品 毛细管区带电泳 

分 类 号：O657.33[理学—分析化学]