Vortex-assisted liquid-liquid microextraction for the simultaneous derivatization and extraction of five primary aliphatic amines in water sample.

Vortex-assisted liquid-liquid microextraction was used to extract and derivatize propylamine, butylamine, pentylamine, benzylamine, and sec-butylamine in various environmental water and refinery effluent samples. Herein, µL-volume of butyl chloroformate as a derivatization agent was added to 1,1,2-trichloroethane as an extraction solvent, allowing for simultaneous extraction and derivatization of the amines. The derivatization agent reacted with the amines in an alkaline medium under mild conditions to create their related carbamates. The carbamate derivatives obtained from primary amines performed well in gas chromatography system. Various affecting parameters of the method, such as the derivatization agent amount, type of extraction solvent, ionic strength of solution, pH, vortexing time, and centrifuging time and rate were carefully optimized. In the end, gas chromatography-flame ionization detector was used to separate, identify, and quantify the enriched derivatives. Under optimal conditions, enrichment factors varied from 440 to 515, while extraction recovery of the desired amines was between 88 and 103%. The limits of detection for amines ranged from 0.4 to 1.0 µg L, and inter- and intra-day precision were in the ranges of 2.2-5.8 and 1.0-3.3%, respectively. Also, relative recoveries were between 85 and 107%. This method proved to be valuable due to its simplicity, sensitivity, high precision, lack of need for special equipment, and high ability in the extraction and derivatization of the selected amines. The use of µL-volume of organic solvents made it economical and environmentally friendly.