On-line preconcentration capillary electrophoresis for purity profiling of synthetic peptides

Chromatography-based on- and in-line pre-concentration methods in capillary electrophoresis

“…A method was optimized and evaluated for the purity control of the biologically active synthetic peptide fas-F (a 28-residue fragment of fasciculin-1) and applied to purity profiling of angiotensin I, oxytocin, bradykinin, and luteinizing-hormonereleasing hormone with an in-line concentrator cartridge, packed with silica-based C-18 particles and coupled near the inlet of the capillary [19]. Fig.…”

Sample enrichment techniques in capillary electrophoresis: Focus on peptides and proteins

“…Schematic representation of the analyte concentrator cartridge. Reprinted from [100] with permission from Elsevier. many cases, however, the increase in signal output is largely limited by the volume of the capillary itself, since a good length must remain for separation of the sample components.…”

“…Instead of nanoliter volumes typically used in CE, at least 25 L of the sample could be loaded, resulting in three to four orders of magnitude improvement in detections limits. Vizioli et al [100] packed a short length of fused silica capillary with silica-based C 18 reversed-phase chromatographic material, and coupled it on-line with the separation capillary (Fig. 4).…”

“…The use of a preconcentrator device at the head of the capillary has been explored in a number of works [73,[99][100][101][102][103]. Waterval et al [85] developed a preconcentrator using commercially available extraction disks containing poly(styrenedivinylbenzene) adsorbent particles in a matrix of inert Teflon to create a mechanically stable sorbent.…”

Oxytocin detection at ppt level in human saliva by an extended-gate-type organic field-effect transistor

“…In particular, quantitative detection of oxytocin levels in human saliva would be an indicator to monitor the relationship between psychological changes and peripheral effects. 8 Oxytocin has been conventionally analyzed utilizing large analytical apparatuses (e.g., liquid chromatography-mass spectrometry (LC-MS) [9][10][11] and capillary electrophoresis, 12,13 while such methods have considerable issues such as the requirement of expensive large instruments and trained personnel, and time-consuming. In the context of the above, the development of a rapid and facile sensing system is desirable.…”