TRANSFERABILITY OF RESULTS OBTAINED FOR SODIUM, POTASSIUM AND CHLORIDE-IONS WITH DIFFERENT ANALYZERS

In this study we have assessed transferability in seven different anal ysers commonly used in clinical chemistry laboratories to measure sodi um, potassium and chloride ions. The inaccuracy and linearity of the t echniques were satisfactory in most cases, and therefore all the equip ment may be used in both pathological and normal ranges of the electro lytes evaluated. In most cases it was possible to correct the inaccura cy. The equipment which gave the best performance when analysing the t hree ions assessed after considering the Process Capability Index (CPI ) and Performance Index (PI) was Nova-5. According to Hyltoft-Petersen 's criteria, the results obtained for the three ions with the differen t analysers cannot be used indiscriminately, apart from potassium. How ever, after comparison of the results obtained by indirect potentiomet ry with those obtained by other techniques, we can conclude that the t ransferability of results is possible in almost every case, as standar d deviation from regression (S-y,S-x) was lower than the permissible a nalytical error. (C) 1998 Elsevier Science B.V. All rights reserved.