Comparison of sample introduction techniques with a continuously heated graphite-furnace atomizer for atomic-absorption spectrophotometry.
A graphite furnace is described which can be operated continuously at temperatures up to 2100 degrees C or be subjected to a temperature ramp running up to 3100 degrees C. Pyrolytic coating of the tubes with carbon before operation was found to be necessary to ensure a satisfactory life-time. Two methods of sample introduction were investigated with a number of salt solutions: continuous nebulization combined with desolvation, with the furnace operated at constant temperature, and deposition of material from an aerosol into the furnace at 150 degrees C for 10 sec before the conventional ramping procedure. The continuous introduction method offers ease of operation, good precision (RSD = 1-1.3%) and moderate sensitivity, but suffers from extensive interferences. The aerosol deposition method combines the merits of conventional furnace atomic-absorption with easier operation, good precision (RSD = 1.8-2.3%) and higher sensitivity.
Chamsaz
M
M
Macaulay Institute for Soil Research, Craigiebuckler, Aberdeen, Scotland.
Sharp
B L
BL
West
T S
TS