Abstract
A flow injection system based on multi-site detection for kinetic spetrophotometric determination of uric acid in urine is described. The system was studied regarding physical dispersion, elimination of sample matrix interferences and applicability to real samples. In the optimized system, the sample is inserted into a water stream which merged downstream with the reagent solution containing iron(II) chloride and TPTZ. This system enables the determination of about 30 samples/h, and yields precise results (RSD usually <2.9%). Sensitivity is 212 mAU l/mmol up to 0.60 mmol/l uric acid. Accuracy was assessed by running 32 samples already analyzed by a conventional enzymatic procedure. No statistical difference between methods was found at the 95% confidence level.
