Direct flame atomic absorption spectrophotometric determination of alkalis in geochemical samples

Abstract

Flame atomic absorption spectrometry has been used for the estimation of the alkali metal content (as Na2O and K2O) in 95 reference materials with diverse matrices (including recently introduced Polish and Chinese standard samples awaiting certification through collaborative studies) using 1000 mu g ml(-1) of lanthanum and 2000 mu g ml(-1) of rubidium as matrix buffers for sodium and potassium, respectively. The +/-t (Student's values for the samples with known recommended values (degree of freedom n - 1 = 9), at the 95% and 99% confidence levels) indicate that within the confidence levels 95-99% there is no statistical difference between the data presented and the reference data for most of the samples. The agreement between the reported data and the results obtained are generally good.