QCM Real‐Time Sensor for monitoring of Poisonous Cyanide from Drinking Water and Environmental

The paper present Quartz Crystal Microbalance (QCM) used for monitoring of poisonous cyanide in real‐time at both drinking water standard and environmental regulatory concentrations. Through the use of a flow cell, aqueous samples containing cyanide react with a gold electrode of a piezoelectric quartz crystal and extract the gold from electrode in solution. The dissolution of metallic gold depends by cyanide concentration, pH of solution, the flow debit and the time. The sensor is an AT‐cut quartz crystal with CrAu or TiAu electrode metallization, 1.27 cm2 active areas and 5 MHz resonance frequency. We use QCM with the static liquid from 0.2 to 1 ml solution and dynamic liquid with flow debit from 0.2 to 1 mL/minute. The detection limits at pH 12 are about 5 ppb for analysis times of 10 min, and 2 ppb for analysis times of 20 minutes. The calibrations show excellent linearity over a variety of cyanide concentrations ranging from 50 ppb to hundreds of ppm. The ability to provide real‐time monitoring of cy...