石墨炉原子吸收光谱法直接测定全血中砷

GF-AAS DETERMINATION OF ARSENIC IN WHOLE BLOOD

研究了石墨炉原子吸收光谱法测定全血中砷的方法。用硝酸镍 重铬酸钾为基体改进剂 ,1∶10稀释 ,建立了基体匹配校准加入法 ,方法检出限低 ,灵敏度高 。

Arsenic in whole blood was determined directly by GF AAS. The blood sample was diluted 10 times with water, and a mixture of 1g·L -1 Ni(NO 3) 2 and 1g·L -1 K 2Cr 2O 7 was used as matrix modifier. Potassium dichromate was added to oxidize organic matters in the sample and also As(Ⅲ) to As(Ⅴ), thus interference of background and loss of trivalent arsenic were efficiently eliminated. Nickel(Ⅱ) was added to form stable arsenate salts with the oxidized pentavalent arsenic. Matrix matching was used in the preparation of working curve, thus various interferences were avoided. Detection limit of this method was found to be 0.69μg·L -1 . RSD′s ( n =5) obtained at 3 concentration levels were in the range from 3.2% to 7.5%. Recoveries found by standard addition method were in the range of 94.5% to 109%.