Enzymatic reverse FIA method for total phenols determination in urine samples.

A reverse flow injection spectrophotometric enzymatic method is proposed to quantify total phenols in urine samples. The polyphenol oxidase (PPO; EC 1.14.18.1) obtained as a crude extract from sweet potato root (Ipomoea batatas) was used as enzymatic catalyze. The detection limit, the sample throughput and relative standard deviation were 7.7mgl(-1) of total phenols, 49h(-1) and 0.9%, respectively. The method was applied to real samples and a recovery study was carried out in order to its validation.