Determination of calcium in petroleum calcium sulfonate by emulsification technology-flame atomic absorption spectrometry

The butyl acetate solutions of sample were emulsified by the emulsifier OP to prepare emulsion. An analytical method for rapid determination of calcium in petroleum calcium sulfonte by emulsification technology-flame atomic absorption spectrometry was established. La~(3+) was used as a releasing reagent. The working curve method was used for the determination with a reference water. The experimental results indicated that viscosity of test solution was identical with that of water and no background absorption was found. The relative standard deviation was less than 0.8%. The recovery obtained was in the range of 100.4%～101.0%. The linear range was 0～12 μg/mL. Detection limit was (0.64 μg/mL). The determination results were consistent with those obtained by ashing method. The relative error between them was less than ±1.4%. This method is convenient.