Response surface methodology in the development of a stacking‐sensitive capillary electrophoresis method by field‐amplified injection for the analysis of tricyclic antidepressants in the presence of salts

Abstract

The work presented here explores the possibilities of the electrokinetic injection (EK) to achieve sensitive methods for the determination of tricyclic antidepressants in biological samples (serum). The addition of ACN to the sample, with high content in salts, causes stacking at the tip of the capillary, in a similar way as for hydrodynamic injection. An experimental design with the response surface methodology has been used to find the optimum composition of the matrix of the sample (sodium chloride and ACN percentages) and the conditions for the EK (water-plug length, time, and voltage of injection) in few experiments. The composition of the separation buffer was the same as utilized in a previous paper. The use of a bubble capillary to reach lower detection limits implies a loss of the resolution and requires a new optimization. Finally, a comparison between electrokinetic and hydrodynamic injections is made.

On‐line preconcentration strategy for the simultaneous quantification of three local anesthetics in human urine using CZE

“…The mobility of the analytes is highly influenced by the dielectric constant and viscosity of the sample solvent . In addition, the difference in the conductivity of the sample and BGE is one the most important factors affecting stacking efficiency . The addition of an organic solvent to the sample medium was taken into account during the optimization of the method.…”

“…When performing FASI, a plug of methanol or another high resistivity solvent can be injected before sample injection, which in some cases can further enhance the sensitivity of this technique , although the same or better sensitivity has been obtained by other authors in absence of the low conductivity zone at the capillary tip . The influence of binary mixtures of methanol/water from 0.0 to 100.0% of methanol and the injection time (0.0‐15.0 s) of the pre‐injection plug, were studied.…”

“…The most important prerequisite for achieving the high sensitivity associated with FASI is that samples need to be free of electrolytes. The presence of salts in sample matrices significantly disrupted the stacking of analytes . Biological samples naturally present high salt and ion contents, which is seriously detrimental for FASI .…”

Response Surface Methodology-Based Optimisation of Agarose Gel Electrophoresis for Screening and Electropherotyping of Rotavirus

“…Although there are reports for the use of RSM for optimisation of parameters of electrophoresis [19,20], to the best of our knowledge, this is the first study involving statistical optimisation of AGE parameters for resolution of rotavirus-segmented dsRNA genome and for detection of miniscule variations in the electrophoretic profile of various long and short forms. In fact, the strength of the study is that the optimised conditions were validated on all the positive 79 samples, and a comparison was also done with PAGE analysis.…”

Simultaneous Differential Pulse Adsorptive Stripping Determination of Imipramine and Its Metabolite Desipramine by the PLS‐1 Multivariate Method

“…Several methods are available to determine Imipramine and its metabolite Desipramine, including capillary electrophoresis, spectrophotometry, gas chromatography and high performance liquid chromatography (HPLC) [1][2][3][4][5][6][7][8].…”