A critical comparative study of atomic-spectrometric methods (atomic absorption, atomic emission and inductively coupled plasma emission) for the determination of strontium in biological materials

Abstract

As part of a general research plan, aimed at establishing tolerable doses of strontium and its distribution in selected soft tissues of rats and hamsters treated with stable strontium, a comparative study on the analytical performance of flame atomic absorption, flame atomic emission and inductively coupled plasma (ICP) emission for biological strontium assays, especially in blood serum, has been carried out. Optimum conditions for the various methods were established and analytical performance characteristics were evaluated for each method in terms of limits of detection, dynamic range, selectivity and precision attainable using the same basic instrument (the Perkin-Elmer ICP/5000).

ICP emission spectrometry appeared to be the best method as it provides a sensitivity of about 100 times better than the next most sensitive method, a linear calibration graph over five orders of magnitude, good precision in real sample analysis and virtual absence of spectral or chemical interferences (although nebulisation and transport effects have to be allowed for) from those elements and organic matrices common in biological materials. A dinitrogen oxide - acetylene flame, in the presence of a sodium content approximating the blood sodium content, increases sensitivity and selectivity when compared with an air - acetylene flame, flame emission being about four times more sensitive than flame atomic absorption for both flames.

Results for the determination of strontium in blood serum, brain and liver of rats and hamsters treated with stable strontium are also reported.