Capillary zone electrophoresis analysis

CE has many separation modes that are beneficial to protein impurity analysis. Within the many thousands of potential protein impurities in a recombinant product there will be several that have only minor physicochemical differences from the drug product. The application of different CE modes can potentially resolve these impurities. CE methods can be divided into four principle modes that are applicable to recombinant protein impurity analysis capillary zone electrophoresis, capillary isoelectric focusing, capillary gel electrophoresis, and micellar electrokinetic capillary chromatography. Each mode will be discussed briefly. Since the technology is so young and still very exploratory, CE methods are developed empirically for specific separations. It is difficult to provide standard protocols for CE impurity analysis. Instead, protocols that can be used as a starting point for impurity analysis will be provided as well as the citation of examples of impurity analyses from the literature to provide additional sources of protocols for interested readers. 

Biomolecule Separations. Advances in chemical separation techniques such as capillary zone electrophoresis (cze) and sedimentation field flow fractionation (sfff) allow for the isolation of nanogram quantities of amino acids and proteins, as weU as the characterization of large biomolecules (63—68) (see Biopolymers, analytical techniques). The two aforementioned techniques, as weU as chromatography and centrifugation, ate all based upon the differential migration of materials. Trends in the area of separations are toward the manipulation of smaller sample volumes, more rapid purification and analysis of materials, higher resolution of complex mixtures, milder conditions, and higher recovery (69). 

CE was recently used for anthocyanin analysis because of its excellent resolution. This technique has different modes capillary zone electrophoresis (CZE), capillary gel electrophoresis (CGE), micellar electrokinetic chromatography (MEKC), capillary electrochromatography (CEC), capillary isoelectric focusing (CIEE), and capillary isotachophoresis (CITP)."° CZE is the most popular method for anthocyanin... 

Saenz-Lopez, R., Femandez-Zurbano, R, and Tena, M.T., Analysis of aged red wine pigments by capillary zone electrophoresis, J. Chromatogr. A, 1052, 191, 2004. 

Bicard, V., Fougerousse, A., and Brouillard, R., Analysis of natural anthocyanins by capillary zone electrophoresis in acidic media, J. Liq. Chromatogr. Rel. Technol, 22, 541, 1999. 

Stuppner, H. and Egger, R., Application of capillary zone electrophoresis to the analysis of betalains from Beta vulgaris, J. Chromatogr. A, 735, 409, 1996. 

Capillary electrophoresis is increasingly used in food analysis due to its separation performance combined with the short time of analysis. - CapiUary electrophoresis recently applied to colorant measurements includes technical variants such as capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography. ... 

Capillary electrophoresis (CE) or capillary zone electrophoresis (CZE) is the technique most often employed in pesticide residue analysis. In its most basic form, free zone electrophoresis, a fused-silica capillary is filled with electrolyte (running buffer or background electrolyte). A potential is applied across the capillary and the cations... 

Altria, K. D. and Simpson, C. F., Analysis of some pharmaceuticals by high voltage capillary zone electrophoresis, Pharm. Biomed. Anal., 6, 801, 1988. 

Cheng, Y.-F. and Dovichi, N. J., Subattomole amino acid analysis by capillary zone electrophoresis and laser-induced fluorescence, Science, 242, 562, 1988. 

Table 1 summarizes several of the experimental methods discussed in this chapter. A need exists for new or revised methods for transport experimentation, particularly for therapeutic proteins or peptides in polymeric systems. An important criterion for the new or revised methods includes in situ sampling using micro techniques which simultaneously sample, separate, and analyze the sample. For example, capillary zone electrophoresis provides a micro technique with high separation resolution and the potential to measure the mobilities and diffusion coefficients of the diffusant in the presence of a polymer. Combining the separation and analytical components adds considerable power and versatility to the method. In addition, up-to-date separation instrumentation is computer-driven, so that methods development is optimized, data are acquired according to a predetermined program, and data analysis is facilitated. 

Janini, G.M., Chan, K.C., Conrads, T.P., Issaq, H.J., Veenstra, T.D. (2004). Two-dimensional liquid chromatography-capillary zone electrophoresis—sheathless electrospray ionization-mass spectrometry evaluation for peptide analysis and protein identification. Electrophoresis 25, 1973-1980. 

Solinova V, Kasicka V, Koval D et al (2004) Analysis of synthetic derivatives of peptide hormones by capillary zone electrophoresis and micellar electrokinetic chromatography with ultraviolet-absorption and laser-induced fluorescence detection. J Chromatogr B 808 75-82... 

Fan et al. [106] developed a high performance capillary electrophoresis method for the analysis of primaquine and its trifluoroacetyl derivative. The method is based on the mode of capillary-zone electrophoresis in the Bio-Rad HPE-100 capillary electrophoresis system effects of some factors in the electrophoretic conditions on the separation of primaquine and trifluoroacetyl primaquine were studied. Methyl ephedrine was used as the internal standard and the detection was carried out at 210 nm. A linear relationship was obtained between the ratio of peak area of sample and internal standard and corresponding concentration of sample. The relative standard deviations of migration time and the ratio of peak area of within-day and between-day for replicate injections were <0.6% and 5.0%, respectively. 

DGE a AC AMS APCI API AP-MALDI APPI ASAP BIRD c CAD CE CF CF-FAB Cl CID cw CZE Da DAPCI DART DC DE DESI DIOS DTIMS EC ECD El ELDI EM ESI ETD eV f FAB FAIMS FD FI FT FTICR two-dimensional gel electrophoresis atto, 10 18 alternating current accelerator mass spectrometry atmospheric pressure chemical ionization atmospheric pressure ionization atmospheric pressure matrix-assisted laser desorption/ionization atmospheric pressure photoionization atmospheric-pressure solids analysis probe blackbody infrared radiative dissociation centi, 10-2 collision-activated dissociation capillary electrophoresis continuous flow continuous flow fast atom bombardment chemical ionization collision-induced dissociation continuous wave capillary zone electrophoresis dalton desorption atmospheric pressure chemical ionization direct analysis in real time direct current delayed extraction desorption electrospray ionization desorption/ionization on silicon drift tube ion mobility spectrometry electrochromatography electron capture dissociation electron ionization electrospray-assisted laser desorption/ionization electron multiplier electrospray ionization electron transfer dissociation electron volt femto, 1CT15 fast atom bombardment field asymmetric waveform ion mobility spectrometry field desorption field ionization Fourier transform Fourier transform ion cyclotron resonance... 

In CZE, the capillary, inlet reservoir, and outlet reservoir are filled with the same electrolyte solution. This solution is variously termed background electrolyte, analysis buffer, or run buffer. In CZE, the sample is injected at the inlet end of the capillary, and components migrate toward the detection point according to their mass-to-charge ratio by the electrophoretic mobility and separations principles outlined in the preceding text. It is the simplest form of CE and the most widely used, particularly for protein separations. CZE is described in Capillary Zone Electrophoresis. ... 

Kaale, E., Van Schepdael, A., Roets, E., and Hoogmartens, J. (2001). Development and validation of a simple capillary zone electrophoresis method for the analysis of kanamycin sulfate with UV detection after pre-capillary derivatization. /. Chromatogr. A 924(1—2), 451—458. 

---