The determination of calcium, glucose, urea and uric acid using the Kodak Ektachem multilayer technology: an evaluation

Summary: Calcium, glucose, urea and uric acid determinations on the "Kodak Ektachem Four Chemistry Analyzer" were tested for precision and an estimation of the accüracy was performed with our laboratory routine methods using patients ' sera and proficiency fluids. Precision — examined over a period of six weeks — was very good. Even the very stringent claim of the College of American Patholpgists (CAP) — that analytical dispersion should be less than l/16th of the normal ränge-- was fulfilled in almost all cöntrol sämples. The results from patients ' sera meas-ured using both the Ektächerri and the routine laboratory methods showed very good correlation. Proficiency fluids tested for calcium, glucose and uric acid all resulted in välues well within the assigned interval. Some negative bias was noted for the urea determjnation hpwever. This could not be completely eliminated even though the sämples had been reconstituted with a bicarbPnate solution according tp the manufacturer's instructions. The linear ränge of the four determinations was checked: calcium is linear up to 4.2 mmol/1, glucose up to 33 mmol/1, urea up to 60 mmol/1 and uric acid up to 1370 /. Our results coiifirmed the long*term stability of the analyzer and slides to be so'high that one calibration per week is sufficient