This article introduces an automated method for the trace metal analysis of slurry samples by graphite furnace atomic absorption spectrometry.
The document details a method for analyzing trace metals in solid samples by suspending them in liquid media (such as glycerine or methanol) and dispensing the slurry directly into a graphite furnace. This approach addresses challenges associated with traditional solid sampling, such as sample heterogeneity and interference effects.
The procedure was tested on various matrices including plant tissues, animal tissues, soil, and sediments using elements like cadmium, lead, copper, chromium, and cobalt. The note provides experimental results demonstrating that direct calibration is often valid for these slurries when appropriate modifiers (e.g., palladium or platinum-palladium) are used.
| Spectrometer Model | Varian SpectrAA-10 |
|---|---|
| Background Corrector | Deuterium background corrector |
| Graphite Furnace Model | GTA-96 |
| Sample Dispenser Type | Programmable sample dispenser |
| Tube Coating | Pyrolytically coated tubes |
Solid sampling saves time for difficult-to-dissolve samples, is convenient when only small amounts of sample are available, and allows for sequential multi-element analysis.
The following elements were determined: cadmium, lead, copper, chromium and cobalt.
A mixture of glycerine and demineralized water with ratios of 2+1 or 4+1 was found to give satisfactory reproducibilities.