Repetitive injection field-amplified sample stacking for cationic compounds determination.
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.
Department of Pharmaceutical Chemistry, Medical University of Gdańsk, Hallera 107, 80-416 Gdańsk, Poland.
Szymon
S
Dziomba
Department of Inorganic and Analytical Chemistry, Medical University of Białystok, 15-222 Białystok, Mickiewicza 2D, Poland.
Michał
M
Biernacki
Department of Pharmaceutical Chemistry, Medical University of Gdańsk, Hallera 107, 80-416 Gdańsk, Poland.
Ilona
I
Olędzka
Department of Inorganic and Analytical Chemistry, Medical University of Białystok, 15-222 Białystok, Mickiewicza 2D, Poland.
Elżbieta
E
Skrzydlewska
Department of Pharmaceutical Chemistry, Medical University of Gdańsk, Hallera 107, 80-416 Gdańsk, Poland.
Tomasz
T
Bączek
Department of Pharmaceutical Chemistry, Medical University of Gdańsk, Hallera 107, 80-416 Gdańsk, Poland. Electronic address: piotr.kowalski@gumed.edu.pl.
Piotr
P
Kowalski
D000639:Amitriptyline / Q000652:urine; D000929:Antidepressive Agents, Tricyclic / Q000652:urine; D002138:Calibration; D002412:Cations; D004573:Electrolytes; D004586:Electrophoresis; D019075:Electrophoresis, Capillary; D005473:Fluoxetine / Q000652:urine; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006919:Hydroxyzine / Q000652:urine; D057230:Limit of Detection; D009888:Opipramol / Q000652:urine; D010756:Phosphoric Acids / Q000737:chemistry; D011312:Pressure; D011395:Promazine / Q000652:urine; D012997:Solvents / Q000737:chemistry; D013696:Temperature; D013881:Thioridazine / Q000652:urine; D016482:Urinalysis / Q000379:methods*
D000929:Antidepressive Agents, Tricyclic; D002412:Cations; D004573:Electrolytes; D010756:Phosphoric Acids; D012997:Solvents; D005473:Fluoxetine; D000639:Amitriptyline; D006919:Hydroxyzine; D009888:Opipramol; C030242:phosphoric acid; D013881:Thioridazine; D011395:Promazine
Capillary electrophoresis; Electromigration techniques; Field-amplified sample stacking; On-line preconcentration techniques; Repetitive injection