DELAY IN SAMPLE ANALYSIS - DOES IT AFFECT THE STABILITY OF ELECTROLYTES

ABSTRACT AIM To determine the effect of immediate separation versus delayed separation of serum on electrolyte analysis. MATERIALS AND METHODS 40 blood samples have been drawn in triplicates and brought to the laboratory. First batch of samples, the control sera separated from clot within 30 minutes of collection and analysed for sodium and potassium . Second batch of samples was centrifuged and processed after three hours and third batch of samples after six hours at room temperature respectively .The stability of analyte was determined by comparing the test values at 3hr and 6hr with the values from 30 minute sample. STATISTICS Anova test was used to compare the values of sodium and potassium at T0(30MIN), T3(3hr), T6(6hr) RESULTS The mean sodium and potassium concentration within 30minutes, 3hr and 6hr are 135.25 2.164mmolL and 4.042 0.339mmolL, 136.025 2.150mmolL and 4.167 0.326mmolL and 136.275 2.291mmolL and 4.232 0.333mmolL. p value for sodium is 0.41 which is not statistically significant and potassium is (0.03) which is statistically significant and ( p value 0.05 considered significant). CONCLUSION The stability of electrolytes was sensitive to delay in analysis. Thus it is essential that the blood samples to be processed timely, to avoid significant preanalytical errors