A portable cyanide analyzer using gold wire electrodes

We report on a continuous flow potentiometric analyzer for cyanide incorporating multiple gold-wire electrodes. The portable apparatus comprised a low-powered peristaltic pump, a Perspex multicell incorporating six indicator and six reference electrodes connected to an eight channel A/D converter. Real-time data may be displayed on a notebook computer. The system performance was optimized for sample peak heights, reproducibility, working ranges and calibration slopes. Well-defined peaks and fast response times (with peak widths <20 s) were observed using a carrier of 0.1 M sodium hydroxide at a flow rate of 5 mL min-1. The repeatability of the electrode response was 2.3 % (n = 5). The log-linear range was 0.25 to 70ppm (9.6 to 2700 μM) with slopes 96, 205 and 450 mV decade-1 for one, three and six electrodes in series, respectively.