This paper introduces a method for analyzing some anions using HPLC and electrochemical detection.
The document details a method for analyzing 16 specific anions, including iodide, nitrite, bromide, and thiocyanate, using HPLC with electrochemical detection (ECD). It highlights the high sensitivity and selectivity of this approach compared to traditional conductivity methods. The note specifies chromatographic conditions, such as column type, mobile phase composition, flow rate, injection volume, and electrode parameters.
A specific application is demonstrated for determining iodide in table salt. The text explains how ECD allows for the selective detection of iodide even in the presence of a large excess of chloride, which would overlap with it under conductivity detection. It also describes the use of an auto-increment mode to optimize the detection potential.
The method can detect four oxidizable anions (iodide, nitrite, bromide, thiocyanate) and twelve non-oxidizable anions including fluoride, chloride, azide, nitrate, phosphite, sulfate, molybdate, hydrogencarbonate, perchlorite, phosphate, selenate, and perchlorate.
The optimum detection potential determined for the analysis of iodide was 1.1 V.