Chemical vapor generation of Cu: optimization of generation media

Acetic acid was used to enhance the efficiency of chemical vapor generation (CVG) of copper. The volatile product was formed at room temperature following merging of the sample solution with a flowing stream of 0.1% NaBH4; ICP-OES was used for detection. A precision of 1.6% RSD (n=11, 0.2 mg/L) was realized at sampling frequencies of about 90/h. A detection limit of 0.4 ng/mL (3sigma) was obtained. Sensitivity was enhanced approximately 8-fold over conventional pneumatic nebulization sample introduction. Compared with CVG in an optimized HCl or HNO3 medium, sensitivity was increased by an order of magnitude using acetic acid and the reductant concentration was reduced to only 10% of that required with HCl or HNO3. The generation efficiency was estimated to be 18% or 70%, depending on the method used to evaluate it. The methodology was successfully used to the determine copper in human hair and low alloy steel certified reference materials.