Determination of magnesium,calcium,strontium,barium by atomization in stainless steel tube——atomic absorption spectrophotometry

A method for determining the alkaline earth metals elements(Mg,Ca,Sr,Ba) by the non-flame atomic absorption spectrophotometry is proposed.The test solution is dropped into a specially prepared stainless steel atomizing tube on top of the flame atomic absorption spectrophotometer.The stainless steel atomizing tube is heated by the high temperature of the flame to make alkaline earth metals elements atomizing and being measured.Atomization under non-flame can avoid the ionization effect of alkaline earth metals elements and overcome the interference from emission spectrum of flame itself and absorption of radiation line of light source produced by flame.The atomizing device of the method is simple.It need not using much de-ionized water to deliver the test solution.The dosage of reagent and discharge of the waste solution are little.The method is suitable for determining the alkaline earth metals elements(Mg,Ca,Sr,Ba) with the characteristic mass of 5.2×10-12-9.5×10-12 g/1% and the detection limits of 5.0×10-12-9.3×10-12 g.It has been applied to the determination of Mg,Ca,Sr,Ba in mineral water samples,giving recoveries of 99.0%-99.3% and RSD of 0.15%-0.32%.