Determination of Volatile Low-Molecular-Weight Amines in Water by Capillary Electrophoresis after Headspace Microextraction

Resumo

A method for the simultaneous determination of ammonium and seven volatile alkylamines (methylamine, dimethylamine, trimethylamine, ethylamine, n-propylamine, isopropylamine, and diethylamine) in aqueous media by capillary electrophoresis after headspace microextraction into a 5-μL drop of a 0.01 M solution of H₃PO₄ was developed. A solution containing 2 mM acridine, 20 mM acetic acid, and 0.05% Tween 20 was chosen as a background electrolyte for indirect photometric detection. Hydrodynamic sample injection was used. The method was tested using the samples of drinking water with the addition of ammonium and alkylamines. The accuracy of the results was confirmed by a standard addition method. The method developed provides an analytical range from 0.003 to 20 mg/L.