Electrothermal atomic-absorption determination of barium in brines and caustic soda solutions.
A method is described for the determination of barium at trace levels (0.2-2.5 ng) in the presence of a large amount of sodium chloride or sodium hydroxide (up to 750,000-fold) by electrothermal atomic-absorption spectrophotometry. The method involves making the sample solutions 1M with respect to nitric acid and directly injecting 5-mul aliquots into a pyrolytic-graphite furnace. Sodium chloride can be completely removed during the ashing stage of the heating cycle, without chemical pretreatment. On the basis of experimental results obtained, an explanation for the negative deviation of the calibration graphs noticed in ETA-AA is given, with nickel and barium atomization data as examples. Factors affecting the atomization peak shape and sensitivity for barium are also discussed.
Jasim
F
F
Department of Chemistry, College of Science, University of Baghdad, Baghdad, Iraq.
Barbooti
M M
MM