Miniaturized salting-out liquid-liquid extraction of sulfonamides from different matrices

Salting-out liquid-liquid extraction (LLE) uses water-miscible organic solvents as the extractants The principle of it is based on the phase separation of water-miscible organic solvents from the aqueous solutions in the presence of high concentration of salts As an effort to miniaturization in the present study a 1-mL syringe was employed as the phase separation device for salting-out LLE Once the phase separation occurred the upper layer could be narrowed into the needle tip by pushing the plunger thus the collection of the upper layer solvent was convenient By miniaturization the consumption of organic solvent was decreased as low as possible Four sulfonamides were used as model analytes The optimal salting-out parameters were as follows 150 mu L of acetonitrile was added to the 500 mu L of sample solution containing 300 mg mL(-1) sodium chloride at a pH of 65 This procedure afforded a convenient fast and cost-saving operation with good cleanup ability for the model analytes It showed promising applications for different matrices Herein food (honey) environmental water (river water) and biological fluid (human urine) were investigated Satisfactory results were obtained An additional bonus of this sample preparation method is that owing to its water-miscible nature the extraction solvent is compatible with various analytical systems like gas chromatography high-performance liquid chromatography and capillary electrophoresis (C) 2010 Elsevier B V All rights reserved