高效液相色谱-电感耦合等离子体质谱联用技术测定海产品中5种形态砷

Determination of five arsenic species in seafood using high performance liquid chromatography(HPLC) coupled with inductively coupled plasma mass spectrometry(ICP-MS)

建立了海产品中5种形态砷(As)的高效液相色谱-电感耦合等离子体质谱联用测定方法。将样品冷冻干燥后采用V(甲醇)∶V(水)=3∶1溶液,70℃水浴振摇30 min提取1次,再用V(甲醇)∶V(水)=1∶1溶液提取2次,提取液用阴离子交换柱分离,以20 mmol.L-1碳酸铵[碳酸氢铵(NH4HCO3)+氨基甲酸铵(NH2COONH4)]为流动相,用电感耦合等离子体质谱检测。5种As的检出限为0.057～0.13μg.L-1,定量限为0.19～0.43μg.kg-1。添加回收率为83.2%～115%,相对标准偏差小于10%。实际海产品样品测定结果表明,海产品中的As主要以砷甜菜碱和二甲基砷酸为主,5种形态As的和与总As相比,总体提取率达90%以上。

A method was established to determine five arsenic species in seafood using high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry （HPLC-ICP-MS）. Freeze dried samples were extracted with methanol-water （3：1 ） shaking in 70 ~C water bath for the first time, and extracted with methanol-water（ 1：1 ） for the second and third time. Then we separa- ted the extract by anion exchange column using 20 mmol-L- 1 NH4 HCO3 ＋ NH2 COONH4 mobile phase, and detected the compounds with plasma mass spectrometry. The detection limit and quantification limit of five arsenic speciations in seafood varied from 0. 057 - 0. 13 pog.L-land from 0. 19 ~0. 43 p.g,kg ~. The average recovery of five species arsenic spiked in tested samples at 3 levels ranged from 83.2% - 115% with the relative standard deviation （RSD） between 2.15% and 9.97%. The proposed method had been applied to the analysis of seafood came from Australia, indicating that arsenobetaine （AsB） and dimethylarsinic acid （DMA） were main spe- cies of arsenic in seafood, and the extraction efficiency of five arsenic speciations were more than 90% , which was higher than of total arsenic.