The term “cyanide” refers to all of the CN groups in cyanide compounds that can be determined as the cyanide ion, CN–. Originating in water primarily from metallurgical and galvanic industrial plants, cyanide is highly toxic to the human nervous system.
Hanna Instruments offers a variety of technologies to measure Cyanide. Colorimetrically, spectrophotometers and photometers are available. For a potentiometric measurement, portable and benchtop pH/ISE meters are available to use with the cyanide ISE for direct ion concentration measurements. Potentiometric titrations systems are available that can perform both direct measurement and a titration method for cyanide.
Below are the most common products used for cyanide measurement.
Spectrophotometers are available that have cyanide method in several ranges pre-programmed into the meter. The spectrophotometer offers the highest precision due to the quality of the optical system that has a wavelength accuracy of +/- 1.5 nm. The spectrophotometer allows for custom methods to be developed.
Single parameter portable photometers are available in two ranges. The portable photometers have a CAL Check feature that allows for performance verification and if needed, recalibration using the CAL Check standards. The portable meters are available as a meter only or as a kit. The kit version include a rugged carrying case and CAL Check standards.
Titrators are available to perform titrations using the cyanide ISE and a silver nitrate titrant. Titration systems offer a precision dosing system to determine the precise amount of titrant used. Titration systems are available with one or two analog board inputs and options for one or two dosing pumps.
Benchtop pH/ISE meters
Benchtop pH/ISE meters include a two channel option in which a pH probe can be connected to one channel and the cyanide ISE to the other. The benchtop meters have the ion charge and formula weight pre-programmed for use with the cyanide ISE. The benchtop meters also have incremental methods pre-programmed including the known addition, known subtraction, analyte addition and analyte subtraction methods.
Portable pH/ISE Meters
Portable pH/ISE allow the flexibility to perform an ISE measurement with a portable even though the ISE measurement method is more suitable to a benchtop environment due to the addition of the ISA to raise the pH and the use of a magnetic stirrer to keep the sample homogenous. The portable pH/ISE meter has the ion charge and formula weight pre-programmed for concentration measurements.
Cyanide electrodes are potentiometric devices used for the rapid determination of free Cyanide ions in effluent, for electroplating bath analysis and as a detector for titration of cyanide with silver nitrate. The electrode functions as a sensor or ionic conductor. The silver halide pellet is practically insoluble in the test solutions being measured and produces a potential change due to changes in the sample’s ion activity. When the ionic strength of the sample is fixed by the addition of ISA, the voltage is proportional to the concentration of Cyanide ions in solution and the electrode follows the Nernst equation.
The cyanide ISE is available as a combination version with both indicating half cell and reference half cell or available as an indicating half cell that will be used with a separate reference half cell.
Solutions for cyanide measurement include ISE standards and ISA for calibration and measurement. Other solutions include the CAL Check standards for verifying and, if needed, the calibration of our portable photometers. Each CAL Check standard is supplied with a Certificate of Analysis stating the accuracy and traceability of the standard.
Accessories include spare cuvettes and caps for photometers, and magnetic stirrers to ensure adequate mixing when using an ISE.