Phenols spectrophotometric determination in waters, with an analysis assembly in automated flow

It is presented an automated flow injection analysis (FIA) method for spect rometric determination of phenols from waters. The FIA manifold is made usi ng a three channels peristaltic pump, a plunger pump, reaction coils and fl ow spectrometric system A computer controls the solenoidal valves operating and records and processes the experimental data. The method is based on th e reaction between phenol and 4- aminoantypirine in presence of potassium p ersulfate. The absorbance of the colored compound obtained in this reaction was measured at 520 nm. Operational parameters such as injected sample vol ume, flow rate and flow cell diameter were optimized. Calibration curve was liniar from 5 to 80 ppm phenol. Detection limit was 5 ppm and relative sta ndard deviation 1,72% (n=15). The throughput of the method was 35 determina tions per hour.