Flame atomic absorption spectrometric determination of the calcium content in foods with flow injection on-line inhibition

Objective:To establish the test method for determining calcium content in foods by flame atomic absorption spectrometry using flow injection on-line inhibition.Methods:In this paper,the concentration of calcium in foods was detected by flame atomic absorption spectrometry,with microwave digestion for sample pretreatment and lanthanum oxide(10 g/L) as releasing agent.The solutions were led to flame atomizer continuously via the system of double capillary of miniature multifunctional injector,one for releasing agent,the other for calcium standard series,reagent blank and the solution of sample digestion in their given order.Results:Better linear relationship had been obtained when the concentration of calcium was 0.50 μg/ml～20.00 μg/ml,its correlation coefficient(r) was 0.9998,the recovery of standard addition was in the range of 96.5%～101.7% and the average recovery was 99.1%,with the RSD of 0.93%.Conclusion:This method was worthy of popularization and application in detection of calcium content for its lower reagent consumption,lower pollution,simple and rapid operation,better reproducibility,higher accuracy and broader linear range.