海产品中无机砷测定方法的研究  

Study on Inorganic Arsenic in Seafood Determined by Liquid Chromatography-Atomic Fluorescence Spectrometry

作　　者：张磊[1] 李筱薇[1] 赵云峰[1] 吴永宁[1] 刘丽萍[2] 张妮娜[2] 

机构地区：[1]中国疾病预防控制中心营养与食品安全所,北京100050 [2]北京市疾病预防控制中心中心实验室,北京100013

出　　处：《中国食品卫生杂志》2009年第2期97-103,共7页Chinese Journal of Food Hygiene

基　　金："十一五"国家科技支撑计划(2006BAK02A10)

摘　　要：目的比较甲醇溶液和三氟乙酸(TFA)溶液对海产品中砷化合物的提取能力,提出海产品中无机砷测定方法,为修订GB/T 5009.11食品中无机砷的测定方法提供依据。方法以不同比例的甲醇溶液和2mol/L TFA溶液为提取剂,超声提取或热浸提后,以正己烷萃取除去脂质成分,萃取液以N2浓缩或减压旋转蒸发至近干,以超纯水溶解残渣,过滤后进样。以20mmol/L磷酸二氢铵(pH6.0)为流动相,以Hamilton PRPX-100离子色谱柱分离,采用液相色谱-原子荧光光谱法(LC-AFS)测定。结果不同比例的甲醇溶液和2mol/L TFA溶液对海产品中砷化物的提取能力存在差异。2mol/L TFA溶液热浸提对无机砷的提取效果优于50%和90%甲醇溶液,且在提取过程中保持样品中主要砷化物形态稳定。采用2mol/L TFA热浸提海藻样品,其无机砷测定结果的FAPAS国际比对考核Z评分为0.3。结论以2mol/L TFA溶液为提取剂,热浸提2h后,采用液相色谱-原子荧光光谱法测定海产品中无机砷含量,方法特异性强,结果准确可靠。Objective To develop a method for determination of inorganic arsenic in seafood by comparing the extracting ability of methanol-water solution and trifluoroacetic acid （TFA） on arsenic compounds in order to pwvide basis for revising the national standard method GB/T 5009.11 ＂Determination of Inorganic Arsenic in Food ＂. Method Inorganic arsenic of seafood were respectively extracted by ultrasonic or heating at 80℃ with 2 mol/L TFA or methanol-water solution. The extracts were extracted by hexane to remove the lipids. The extracts were evaporated to nearly dryness with N2 or decompression rotary evaporator, and dissolved in ultra-pure water. The mobile phase was 20 mmol/L NH4H2PO4 （pH6.0）. Arsenic species were separated with an anion exchange column Hamilton PRPX-100 and detected by liquid chromatography-atomic fluorescence spectrometry （LC-AFS）. Results The differences between methanol-water solution and trifluoreacetic acid at the aspects of extracting inorganic arsenic in seafood were found. The ability of extracting inorganic arsenic with trifluoroacetic acid by heating was much stronger than other extracting solution. The main arsenic species in seafoods were steady during procedures. The samples were extracted with trifluoroacetic acid by heating 2 h, and the Z-score for determination of inorganic arsenic in seaweed, obtained from FAPAS, was 0. 3. Conclusion Inorganic arsenic and DMA, MMA were extracted with trifluoroacetic acid by heating 2 h and accurately determined by LC-AFS in seafood, meanwhile the dominating arsenic species were steady.

关 键 词：砷 色谱法 液相 光谱法 荧光 海味 

分 类 号：R155.5[医药卫生—营养与食品卫生学]