Dionex ED40 Electrochemical Detector

The Dionex ED40 Electrochemical Detector is a sophisticated analytical instrument designed for precise measurement of current generated by applying potential (voltage) across electrodes within flow-through cells. By varying the method of potential application and current measurement, this detector is capable of determining multiple properties of the solution in question, addressing core analytical queries concerning the composition and concentration of analytes.

While the UV-visible absorbance detector is predominant in high performance liquid chromatography (HPLC) due to its excellent sensitivity for many analytes, particularly aromatic compounds, it falls short for nonchromophoric molecules—aliphatic organic compounds and inorganic ions—due to their poor UV absorbance. Although low wavelength UV detection can be employed, this often comes at the cost of reduced selectivity. Similarly, refractive index detection, though an alternative, is challenged by baseline stability difficulties and generally yields lower sensitivity and selectivity compared to UV detection.

Electrochemical detection presents a powerful solution by offering superior sensitivity for a diverse range of nonchromophoric compounds. These include carboxylic, sulfonic, and phosphonic acids; alcohols, glycols, aldehydes, and carbohydrates; primary, secondary, tertiary, and quaternary amines; as well as sulfates, sulfoxides, thiols, sulfides, mercaptans, and various inorganic anions and cations. Moreover, compared to UV absorbance, electrochemical detection significantly enhances sensitivity and selectivity for certain compounds, such as amines and hydroxy-substituted aromatics, including catecholamines. This makes the Dionex ED40 an invaluable asset for laboratories requiring precise detection and quantification of these molecules in complex matrices.