SOLENOID PUMPS FOR FLOW-INJECTION ANALYSIS

Methods employing now injection analysis (FIA), particularly for in si tu seawater techniques, would benefit from reduction in pump size and power requirement, longer maintenance intervals, and the ability to in corporate microprocessor control of each reagent and sample now stream , In this work, the peristaltic pump of a conventional FIA system was replaced by three solenoid-driven diaphragm pumps with integral Viton check valves, and the system was tested by performing the simple nitri te analysis, which has well-defined FIA performance characteristics. S ixty injections per hour were possible with now rates of 0.5 mL/min fo r reagents and sample, The coefficient of variation was 1% for 10 mu M NO2- concentrations, and the detection limit was less than 0.1 mu M N O2-. These values match the reported performance for this method using peristaltic pumps.