ICP-MS Determination of Inorganic Arsenic in Meat Food with IC Separation

Sample of ground meat was dispersed with water,and extracted ultrasonically for 40 min.Acetic acid (3+97) was added to the extract to precipitate protein which was separated by high speed centrifugation at 4 ℃.The supernatant was taken and filtered on 0.45 μm filtering membrane.IonPac AS 18 anion chromagraphic column was used for separation of inorganic arsenic (Ⅲ and Ⅴ) and organic arsenic compounds of methylarsine (MA) and dimethylarsine (DMA).Potassium hydroxide solutions of different concentrations were used as mobile phase in gradient elution of the 4 species of arsenic in forms of their anions,in the alkaline solutions.The eluates were used for ICP-MS determination of inorganic As(Ⅲ) and As(Ⅴ),with values of detection limits (3S/N) of 0.3 and 0.5 μg·kg-1,respectively.Tests for recovery and precision were made by standard addition method at 3 different concentration levels,the results obtained were as follows: ① for As(Ⅲ),recovery 83.1% to 93.3%,RSD′s (n=6) 3.3% to 6.7%;② for As(Ⅴ),recovery 85.3% to 97.6%,RSD′s (n=6) 3.1% to 5.9%.