UREA DETERMINATION IN DIALYSIS, BASED ON A DIFFERENTIAL PH TECHNIQUE

The application of a new technique, based on differential measurements of pH, to determine urea concentration in patients of a dialysis center, is reported. Urea in plasma, whole blood or dialysis fluids is measured by an enzymatic reaction, with urease; the procedure, requiring 10 microL of sample, is simple, fast and correlates well with a reference spectrophotometric method, in the 0-300 mg/dL concentration range, according to the equation y = 1.0291 X -0.0777; r = 0.9991; n = 73.