Separation and on-line preconcentration by stacking and sweeping of charged analytes in the plant by microemulsion electrokinetic chromatography with nonionic surfactants

Online Concentration of Bacteria from Tens of Microliter Sample Volumes in Roughened Fused Silica Capillary with Subsequent Analysis by Capillary Electrophoresis and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

“…The front of the zone was focused but the end of the zone was tailing through the low concentration of the micelles at the BGE/sample matrix interface. , Therefore, the concentration of Brij 35 was increased from 0.05 to 0.1% (v/v), and the records of these experiments are shown in Figures and . Thus, the optimum concentration of micelles in the BGE necessary for desorption of the cells from the inner FS capillary surface and for anionic analysis of the cells during tITP/MEKC was reached. ,,− The narrow peak of the MSSA cells was detected again …”

“…44 EtOH increases the affinity of the cells for the micelle phase without affecting stacking. 33,34 Both additives also play a significant role in desorption of the cells from the capillary surface. LOD for the analysis utilizing static adhesion in roughened FS capillary was determined as 1 × 10 6 cells mL −1 for MSSA, which is 2 × 10 3 cells suspended in 2 μL of PSS (Table 1).…”

“…In this pilot study, we present the accumulation (concentration) of bacteria from large volumes (up to 100 μL) of high conductivity model matrices, physiological saline solution (PSS), bovine blood serum (BS), and human blood, by static or dynamic cell-surface adhesion onto the roughened part of the FS capillary etched with SCW with their subsequent online desorption and analysis by different CE methods. The combination of polymer-enhanced transient isotachophoresis (tITP) from a high conductivity matrix and sweeping of charged cells in the micellar electrokinetic chromatography (MEKC) using nonionogenic surfactant Brij 35 ,,− have been used for concentration and separation of the adhered cells.…”

Sweeping under controlled electroosmotic flow and micellar electrokinetic chromatography for on-line concentration and determination of trace phlorizin and quercitrin in urine samples

“…While it provides highefficiency separations, the detection limits are higher due to the small sampling volume. A number of on-line concentration strategies have been developed, for example, field amplified sample stacking [1][2][3], isotachophoresis (ITP) [4,5], dynamic pH junction [6,7], pH-mediated stacking [8][9][10], and sweeping [11][12][13]. Sweeping is an effective and convenient way for doing on-line sample concentration in MEKC.…”

Stacking As Sample On-Line Pre-concentration Technique in Microemulsion Electrokinetic Chromatography

“…This is followed by switching the polarity back to the positive mode to carry out the actual separation of stacked analytes. This technique has been widely applied to improve detection sensitivity in MEEKC determination of many drugs of different polarities [3].…”