Comparison of Plasma Sodium and Potassium Results Obtained by the Flame photometer and Ion Selective Electrode Techniques

Abstract

This study was carried to compare results of plasma sodium and potassium that, measured by flame photometer and ion selective electrode (ISE). The analysis was done in International Private Hospital (diagnostic center) and Ombdda Teaching Hospital. Fifty specimens were included in the study, 20 specimens with normal sodium and potassium, 15 specimens with low sodium and 15 specimens with high potassium levels. The specimens (plasma) were measured by both techniques (flame photometer and ISE) and the results presented in tables and figures. Statistical analysis of the result (independent t-test) showed there was a significant difference obtained by the two instruments, which was due to variation in plasma water, interference from other ions, residual liquid junction and binding of ion to protein or other legend when using ISE. Fluctuation in light source may be the cause in the variation of results when using flame photometer. The results show that ISE is better than flame photometer in determination of plasma sodium and potassium. Further studies must be done for accuracy and precision for any new methods.