微波消解-树脂分离-石墨炉原子吸收光谱法测定钛铁矿中砷

Determination of arsenic in ilmenite by graphite furnace atomic absorption spectrometry after microwave digestion and ion exchange resin separation

建立了微波消解处理样品、离子交换树脂分离富集，石墨炉原子吸收光谱法测定钛铁矿中砷的方法。考察了溶液的pH、洗脱条件等因素对分析物分离富集的影响，结果表明，在pH 6．0时，砷可以被717型强碱性苯乙烯阴离子交换树脂定量富集，吸附于树脂上的砷可以用0．3m01／LHNO3完全洗脱，采用石墨炉原子吸收光谱法测定。方法检出限为0．10gμ／L，线性范围0．33～100μg／L。对标准样品进行分析验证，结果与认定值相符；用于铁矿样品中砷的测定，结果与Ag—DDTC方法一致，RSD为2.85％～7.82％，加标回收率为98．0％～104．0％。

A method for the determination of arsenic in ilmenite by graphite furnace atomic absorption spectrometry （GFAAS） with microwave digestion and ion exchange resin separation was established. The experimental conditions that influence the sample separation and enriching such as pH of solution, elution conditions and so on were investigated and optimized. At pH 6.0, arsenic was retained on the strong base type ion exchange resin of 717 type, then eluted with 0.3 moL/L nitric acid and determined by GFAAS.The method could avoid the disturbance of impurity in the sample, and was proved to be accurate and reliable. The linear range of the method is 0.33 μg/L to 100 μg/L,and the detection limit is 0.10 /μg/L.The method has been applied to the determination of arsenic in standard reference samples and the results are in good accordance with certified values.The method has been applied to analyze the sample with the RSDs of 2.85 % - 7.82 % and the recoveries of 98.0 % - 104.0 % .