Abstract
We evaluated ion-selective electrode instruments on Na, K and Cl, especially for accuracy problems. The instruments used for this study were NOVA I, CLIN-ION AI-3, STAT-ION II and HITACHI 702 models. The results from these instruments were compared with those from IL-443 flame photometer and HIRANUMA chloride meter.
The values of aqueous standard solution, such as NaCl or KC1, obtained from these instruments except NOVA I did not agree with theoretical values, even the values from STAT-ION II and HITACHI 702 which used sample-dilution method were not affected with ionic strength.
The values of commercial control sera obtained from these instruments were different from the stated values. Especially the values of potassium on Versatol A from CLIN-ION AI-3 and STAT-ION II and values of chloride on Hyland from HITACHI 702 differed 10% over from the stated values.
On the sodium levels of 100 patients sera estimated from these instruments, higher values (2mEq/l) by NOVA I and lower values (1mEq/l) by STAT-ION II were obtained respectively. And higher values (2mEq/l) of chloride were obtained by CLIN-ION AI-3, STAT-ION II and HITACHI 702.
We concluded that the variation in among instruments apparently deserve continual attention.
