method of determining 2,4-dichlorphenoxyacetic acid in water solutions

摘要

A method of determining 2,4-dichlorphenoxyacetic acid includes preparation of a sample for analysis, separation of 2,4-dichlorphenoxyacetic acid from the impurities and quantification by high performance liquid chromatography. The sample preparation for analysis is done by adding to the sample of significant excess of cetyletrimethylammonium bromide and bringing the pH to 8.5-9.0. Separation of 2,4- dichlorphenoxyacetic acid from the impurities is carried out by passing the solution through a column with silica modified by polyoxyethylized isooctile phenol, washing the column with distilled water, drying with subsequent desorption of the analyte by acetonitrile and filtration of eluate through a membrane filter. As mobile phase for HPLC a mixture of acetonitrile and water and acetic acid in volume ratio 40: (59-60): (0.5-1,5) is used.