原子荧光法测定食品总砷的前处理方法探讨_屈明华.pdfVIP

2013, Vol.34, No.10 177 (() 311400) () ( IMEP 112) Different Pretreatments for Determination of Total Arsenic in Foods by Atomic Fluorescence Spectrometry QU Ming-huaTANG Fu-binNI Zhang-lin (Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Quality Testing Center for Edible Forest Products of State Forestry Administration (Hangzhou), Fuyang 311400, China) Abstract An atomic fluorescence spectrometric (AFS) method was developed for the determination of total arsenic in wheat, vegetable and algae. Two sample pretreatments were proposed based on digestion with either HNO -HClO or HNO - 3 4 3 HClO -H SO . Basically similar results were obtained by both sample pretreatments. Improved digestion of algae was 4 2 4 achieved by using H SO due to its high boiling point, and the validity of this digestion method was confimed by proficiency 2 4 testing according to IMEP-112: Total and Inorganic Arsenic in Wheat, Vegetable Food and Algae. The chemical speciation of inorganic arsenic was dominant in wheat and vegetable. Low boiling point acid was suitable for digestion of samples with simple chemical speciation of arsenic and therefore enabled accurate determination of total arsenic. In the case of algae samples, which are rich in organic arsenic, full conversion of organic arsenic to inorganic arsenic could only achieved by the use of high boiling point acid for accurate determination. Key words atomic fluoresence spectrometry wheat vegetable algae pretreatment total arsenic TS207.3