A Study of the Determination of Rubidium in Human Erythrocytes by Atomic Absorption Spectrophotometry

In the determination of Rb by atomic absorption spectrophotometry (AAS), potassium or cesium are recommended to be added to interfere with the ionization of Rb but the amount of the ion to be added is something vague. And as far as the reports concerning the determination of Rb in biological fluids especially in human erythrocytes by AAS were surveyed, only a few papers were found to be mentioned it but the method were different from each other as follows; one report recommended to add only sodium to increase the sensitivity, another suggested to add potassium only, but the other recommended to add both cations for the same purpose.
The purpose of the present study is to elucidate a rapid and accurate method to determine Rb in human erythrocytes.
When erythrocytes were diluted 1:50 with potassium at the final concentration of 10,000 ppm, following results were obtained.
1) Sensitivity of absorbance increased about a threefold compared to that with no addition.
2) Concentrations could be determined within the range from O to 60 ppm.
3) Influences of coexisting cations in erythrocytes such as potassium, sodium and so on within the physiological range could be negligible.
4) Influences of acids, such as nitric acid and hydrochloric acid, used during preparation or determination could be also negligible.
5) Preparations of erythrocytes such as wet-ashing with nitric acid or deproteinization with trichloroacetic acid (TCA) were appeared to be needless.