Emission Spectrophotometric Determination of Trace Elements In Air Pollutants

Application of Co-precipitation Methord with Organic Chelating Agent

Abstract

The trace elements in air pollutants were preconcentrated on the basis of co-precipitation method with suitable organic chelating agents, and determined by emission spectrophotometry. The nine trace elements were analyzed by this method.
Namely, these trace elements were leached out with 50ml of 6-Mol. hot hydrochloric acid from the glass fiber filter in which particulates in air pollutants were collected. This procedure was repeated twice. The sample solution were filtered out, and diluted to approximately a 150ml volume with twice distilled water.
After, a 10 mg of Indium as a carrier and 10μg of Palladium as a internal standard were added to this sample solution, a 10ml of 10% oxine-acetic acid solution, 4ml of 1% thionalide-gracial acetic acid solution, and 4ml of 10% tannic acid aqueous solution were added. Then, pH of solution was precisely adjusted to 5. 2 with ammonium hydroxide or acetic acid and allow the sample to stand overnight to ensure complete precipitation.
Filter the precipitate using Millipore Filter (HA. 47mm pore size 0.45μ) and transfer the precipitate to a quartz crucible. The precipitate was ashed at 450°C for about ten hours. After ashing, added sufficient high purity graphite powder of 1/2-fold vs. ashweight and mixed sufficiently. The sample-graphite mixture was loaded into carbon electrode (3mm × 3mm cup type) and arced for 2minutes.