AN173: Direct Determination of Cyanide in Drinking Water by Ion Chromatography with Pulsed Amperometric Detection (PAD)

Instrument Type: IC

Cyanide, a well known acute toxin, occurs both naturally and as an industrial contaminant. In the U.S., cyanide contamination in drinking water is typically from an industrial source or leached from waste sites. In EPA Method 335, samples are individually acid- or UV-digested to convert all cyanide compounds to hydrogen cyanide gas which is distilled into sodium hydroxide (pH 13). These high pH matrixes can cause interferences in spectrophotometric methods. Here free cyanide is separated by IC and detected electrochemically using Ag working electrode and waveform for cyanide determinations.

AN227 Determination of Total Cyanide in Municipal Wastewater

Instrument Type: IC

In this Application Note, we describe an ion exclusion chromatography (ICE) method with pulsed amperometric detection (PAD) using a Pt disposable working electrode and an optimized waveform to determine total cyanide in drinking and wastewater samples. The samples are acid distilled, trapped in 1 M NaOH, and diluted to 250 mM NaOH prior to analyses using the EPA-approved MICRO DIST™ sample preparation system. This ICE-PAD method has the advantages of eluting cyanide before sulfide with Rs > 3, and excluding other interferences, such as chloride and sulfate that typically interfere in ion ...