A sensitive high-temperature electrothermal atomic absorption analysis for Rb+ in erythrocytes and plasma of normal and hypertensive persons
Hallis KF., Boon NA., Perkins CM., Aronson JK., Grahame-Smith DG.
This method for determination of Rb + in human plasma and erythrocytes by graphite-furnace atomic absorption spectrophotometry has a sensitivity of 29 nmol/L for plasma 12 nmol/L for erythrocytes. The detection limit is 24 nmol/L for plasma, 4.8 nmol/L for erythrocytes. This assay is approximately 30-fold more sensitive than previously reported techniques involving atomic absorption spectrophotometry, enabling use of smaller samples. The rubidium signal is linear with concentration up to 1.2 μmol/L, and addition of other cations to the matrix produces only minor alterations in the Rb + signal. We measured plasma and erythrocytic Rb + concentrations in healthy subjects and in patients with untreated essential hypertension. In both, our values are similar to those previously reported for healthy individuals.