The document describes the determination of Cd, Cr, Cu, Ni, and Pb in a concentrated CaCl2/NaCl solution using AAS. The analysis of such a high solids containing solution presents challenges, which are addressed through indirect flame atomization, direct flame atomization, and graphite furnace atomization methods. It is important to clean the nebulizer and measure a reagent blank during the analysis. The results are compared against a calibration graph. The document provides calibration data for Cd.
The document addresses the analytical challenge of measuring trace heavy metals in a high-solids caustic suspension containing calcium chloride and sodium chloride. It highlights issues such as burner blockage and nebulizer damage caused by the matrix, necessitating specific measurement techniques.
Three methods are evaluated: indirect flame atomization, direct flame atomization, and graphite furnace atomization. The text provides detailed instrumentation parameters, chemical preparation steps, calibration data tables, and comparative results to demonstrate that the graphite furnace technique is best suited for achieving the required low detection limits.
| Instrument Model | Agilent SpectrAA20B Atomic Absorption Spectrometer |
|---|---|
| Graphite Furnace Model | GTA-96 graphite furnace atomizer |
The graphite furnace technique is best suited because the sensitivity of flame AAS was often inadequate due to low detection limits.
The heavy metals Cd, Cr, Cu, Ni and Pb must be determined.