氢化物发生-冷阱捕获-色谱分离-原子吸收法测定天然水中砷的形态

Determination of Arsenic Species by Hydride Generation/Gold Trapping/Gas Chromatograph/Atomic Absorption Spectrometry in Natural Water

研究建立了氢化物发生－冷阱捕获－色谱分离－原子吸收方法测定天然水中四种主要砷形态。测试系统自行组装，色谱住填料采用ChromosorbGAW－DMCS（粒径0．3～0．45mm），其上涂布3％OV－101。方法的检出限以砷计分别为：As（V）0．51ng，As（Ⅲ）0．43ng，MMA0．38ng，DMA067ng；12ng砷标准偏差As（Ⅴ）4．21％，As（Ⅲ）3．56％，MMA3．23％，DMA5．46％。在0～50ng砷量范围标准曲线线性关系良好。该法适用性广，已用于湖水、河水、海水和地下水等不同水样神形态测定，加标回收率93．5％～104．9％。给出了上述水样四种砷形态的分析结果。

A method of hydride generation/cold trapping/gas chromatography/atomic ab sorption combination has been set up. Chromosorb GAW-DMCS(particle size 0. 3~ 0. 45 mm) coated 3% OV-101 is used as chromatographic packing material. Detection limits in terms of As are As(Ⅴ ) 0. 51 ng, As,(Ⅲ) 0. 43 ng, MMA 0. 38 ng, DMA 0. 67 ng, and the relative standard deviations for 12 ng As are As (Ⅴ ) 4. 21%, As (Ⅲ ) 3. 56%, MMA 3. 23 %,DMA 5. 46%, respectively. Linearity of calibration curves in the range of 0~50 ng As is very good. This method was used to determine arsenic species in lake. river, sea and underground waters. Recoveries of each species in water sample are between 93. 5% and 104. 9%. The analytical results for the four arsenic species are given.