Dziomba Szymon, Biernacki Michał, Olędzka Ilona, Skrzydlewska Elżbieta, Bączek Tomasz, Kowalski Piotr
Department of Pharmaceutical Chemistry, Medical University of Gdańsk, Hallera 107, 80-416 Gdańsk, Poland.
Department of Inorganic and Analytical Chemistry, Medical University of Białystok, 15-222 Białystok, Mickiewicza 2D, Poland.
Talanta. 2014 Jul;125:1-6. doi: 10.1016/j.talanta.2014.02.045. Epub 2014 Feb 27.
The development of a field-amplified sample stacking technique is presented. Sensitivity enhancement in this technique was obtained by repetitive injections of a sample followed by steps of sample matrix removal through the application of counter-pressure. Under optimized conditions the background electrolyte (BGE) was composed of 80 mM H3PO4 while the sample matrix contained 0.5mM H3PO4 and 30% (v/v) methanol. The elaborated method enabled a 4-fold effective injection of the sample (53 s, 0.5 psi). Each injection was followed by a focusing step during which the application of a voltage (2 kV) and counter-pressure (-1 psi) was performed for 0.65 min. The method was developed for the determination of six psychiatric drugs (opipramol, hydroxyzine, promazine, amitriptyline, fluoxetine, and thioridazine). The elaborated method was applied for analysis of human urine samples after a simple liquid-liquid extraction procedure. The detection limits obtained were in the range of 2.23-6.21 ng/mL.
