An Automated Multi-Pumping Pulsed Flow System with Spectrophotometric Detection for the Determination of Phosphate in Natural Waters

Abstract

In this work, an automated multipumping pulsed flow system was implemented for the determination of phosphate in natural waters. The developed flow approach was based on the spectrophotometric determination of phosphate by using the vanadomolybdate reaction. The exploitation of a very simple manifold configuration relying on the utilization of just two active components, in this case two solenoid actuated micropumps that were accountable for sample and reagent insertion and commutation, reaction zone formation, and solutions propelling, provided a great operational and optimization simplicity, low reagent consumption, and waste minimization. Linear calibration plots for phosphate concentrations of up to 20 mg L−1 (R2 = 0.999, n = 6) were obtained, with a detection limit of 0.2 mg L−1. The sampling rate was about 60 samples per hour. The system was applied to the monitoring of phosphate in local streams at specific sampling stations.