Enhancement Effects of Some Organic Complexing Agents on Atomic Absorption Spectrometry of Calcium Using Air-Acetylene Flame

The effects of the twenty organic complexing agents on the absorbance of calcium in AAS by air-acetylene flame are examined. The atomic absorption signals for Ca are enhanced by all agents added except four ali-phatic acids,especially sulphosalicylic acid(SS) is the most remakable.The effects of SS on calcium absorption are investigated in detail. The mechanism of the enhancement and suppression effects are explored preliminarily.
In the presence of 0.1M SS, with increasing the absorbance of Ca to about150%,the interference of some ions is suppressed partly, so that the linearity of calibration curves is improved.
It is revealed that sulphosalicylic acid acts not only as an atomic absorption enhancer but also as an interference suppressor in the determination of calcium by air-acetylene flame AAS. The results obtained for artificial steel samples are satisfactory.