Flow Injection Analysis (FIA) Technique As a method for Indirect Determination of Urea Quantity in Human Blood Serum

Abstract

A new method for the determination of Urea in human blood serum based on
Flow Injection Analysis (FIA) is described. This method is relay on the decrease in the
reduction peak height (Hp) of Sodium nitroprusside Na2[Fe(CN)5NO].2H2O which appeared
at (-0.55 V) vs. (Ag/AgCl, Sat. KCl) using phosphate buffer (pH=6.8) as a supporting
electrolyte and carrier through the enzymatic reaction in the presence of Urease. The method
is sensitive and rapid and the procedure was successfully applied to determination of Urea
quantity in various human blood serum samples represent different cases such as:
Dehydration (for Children), Heart failure, Liver failure and Kidney failure (for Adults).
The results for FIA method have been compared with those obtained from the
colorimetric method for (45) samples and show a good agreement between the two methods
with correlation coefficient (r = 0.99997).