Advances in Automated Cyanide Analysis

Wet Chemistry Automation
Poster Presentation

Prepared by , M. Terrell
PerkinElmer, 710 Bridgeport Ave, Shelton, CT, 06484, United States


Contact Information: tim.smith@xyleminc.com; 979-690-5229


ABSTRACT

The first generation of U.S. EPA cyanide analysis methods for Cyanides Amenable to Chlorination ([CATC] 335.1) and Total Cyanide (335.2) date back to the 1970s. The acid distillation step and colorimetric chemistries employed in these methods are susceptible to matrix interferences and are known to cause either negative or positive analytical biases. The preliminary distillation step in these methods is also labor-intensive, increases the cost per analysis, and has a significantly lower sample throughput rate than nondistillation methods. Newer U.S. EPA and ASTM methods (e.g., OIA-1677, D 6888-09, and D 7511-12), based on gas-diffusion amperometry, were specifically developed to mitigate the interferences associated with methods involving a distillation step. OI Analytical is the only continuous flow analyzer company that provides both SFA and FIA. The OIA 1677 Available Cyanide was developed by OI Analytical in cooperation with the University of Nevada – Reno Mackay School of Mines, and approved by the USEPA for NPDES reporting on December 30, 1999

ASTM D6888-04 / OIA 1677 – Available Cyanide
OI Analytical developed the first non-distillation cyanide method (OIA 1677) that analyzes available cyanide by ligand exchange, gas diffusion –amperometry. This method determines the same cyanide species as amenable (CATC) or weak acid dissociable (WAD) methods without the interferences or labor intensive preliminary processing. ASTM D6888-04 is the same method as OIA 1677 and was written using OI
Analytical instrumentation.

ASTM D7511-09 / OIA1678 – Total Cyanide
OI Analytical developed the first non-distillation method for the determination of total cyanide. This method overcomes the multitude of interferences that result from high temperature acidic digestions/distillation and interferences that result from the pyridine
barbituric acid colorimetric measurements. The method is a “green” chemistry and elimination of digestion with boiling acid makes the method safe for analysts in daily operation.