AUTOMATED FLOW INJECTION ANALYSIS DEVICE AND METHODS FOR DETERMINATION OF CHLORINE IN DRINKING WATERS
ANDREI F. DANET, MIHAELA-CARMEN CHEREGI, MIHAELA BADEA, ARINA RADU, HASSAN Y. ABOUL-ENEIN
A flow injection (FI) device with spectrophotometric detection based on utilization of a peristaltic pump, four solenoid valves with three ways and a spectrophotometric flow cell were designed and optimized for the chlorine determination in drinking waters. The FI device was entirely conducted by a computer and data acquisition and processing were performed using VISUAL LAB software. Two analytical methods based on the N,N-diethyl-p-phenylenediamine (method I) and o-tolidine (method II) enhanced reactions with chlorine. Method I allowed the chlorine determination in the range 0.1 - 10 mg/mL and method II in the range 0.05 - 8 mg/mL. The sampling rates were: 120 samples/h and 90 samples/h, respectively. In order to minimize the consumption of reagents, a new flow methodology based on the “tandem injection” of samples and reagents was tested.