We evaluated the 5-band Serum Proteins by Capillary Electrophoresis kit (Bio-Rad Laboratories, Hercules, CA, U.S.A.) on the BioFocus 2000 CE (Bio-Rad) against conventional agarose gel electrophoresis (AGE) (Helena Laboratories, Beaumont, TX, U.S.A.). Serum from 60 patients was initially screened by AGE and divided into three groups: 1) normal electrophoretic pattern (n = 36, mean total protein 67.7 g/L), 2) monoclonal/oligoclonal gammopathy (n = 14, mean total protein 78.8 g/L), and 3) polyclonal gammopathy (n = 10, mean total protein 77.4 g/L). These samples were concurrently analyzed on the BioFocus 2000. Intraassay and interassay CVs for the five fractions for a normal sample were 0.17-1.44% and 0.42-9.11%, respectively, and 0.21-3.37% and 0.29-3.61%, respectively, for a sample with monoclonal gammopathy. Correlation coefficients for albumin and the albumin/globulin (A/G) ratio were 0.8891 (albumin range 17-93 g/L) and 0.8276 (A/G ratio range 0.39-7.81), respectively. The A/G ratio alone could not discriminate between the three groups. Capillary zone electrophoresis (CZE) correctly identified 33 of 36 samples in the normal group, and 22 of 24 samples in the other two groups, giving a clinical sensitivity and specificity of 91.7%. Our preliminary evaluation shows that protein separation by CZE is a simple, rapid, and automated alternative to conventional AGE.

The history and present status of capillary electrophoresis in China are critically reviewed. Features of major research and future prospects are described.

Capillary electrophoresis was used for the separation of humic acid (HA) from peat, soil, and vermicompost. The electropherograms show the presence of at least three peaks eluted between 6 and 11 min for all HA. The best analysis resolution was obtained with the use of borate buffers at pH 8.9. The HA analyzed have structural and charge similarity, which increases the difficulty of separation. Therefore, the shape of the peaks is broad and the CE profiles of all HA are similar. It is reasonable to assume that the broad band in the three regions is due to the acidic groups that have a similar structure. By comparing the results obtained for HA extracted from soil, peat, vermicompost, and the commercial sample, HA from peat had the major carbon content.

Recent advances in capillary electrophoresis methodology to improve the detection sensitivity for inorganic ions are briefly reviewed. Specifically discussed are current developments of nonabsorbance-based CE detectors and on-capillary enrichment techniques as well as some possible future perspectives.

A method of micellar electrokinetic capillary electrophoresis for determining the six flavonoids in Scutellariae Radix (i.e., baicalin, baicalein, wogonin 7-O-glucuronide, wogonin, oroxylin A 7-O-glucuronide, and oroxylin A) has been developed. The buffer solution (pH 7.24) composed of 20 mM sodium dodecyl sulfate (SDS), 20 mM sodium dihydrogen phosphate, and 25 mM sodium borate was found to be the most suitable electrolyte for the separation. The contents of the six flavonoids in crude Scutellariae Radix could easily be determined within about 15 min. On-column UV (254 nm) monitoring allowed the quantitative determination of baicalin. The effects of pH, surfactant concentration, and applied voltage on the migration behavior of the solutes were studied.

L. tenuis and L. corniculatus seeds are morphologically very similar but their purchase prices are quite different. Chromosome number counting is the only test used thus far in laboratories for the identification of these seeds. Recently, the flavonol's pattern has been used as a criterion for differentiation. In the present work, we studied the storage protein patterns of different Lotus seed samples by capillary gel electrophoresis (CGE), as an alternative method, comparing it with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The seeds were treated according to International Seed Testing Association (ISTA) recommendations. CGE separations were performed using an uncoated capillary of 18 cm effective length and 50 microns i.d. and the Bio-Rad Protein Kit (Hercules, CA, U.S.A.). On-line detection was carried out at 220 nm.

The objective of this study was to utilize linear discriminant analysis (LDA) in the interpretation of capillary electrophoresis-sodium dodecyl sulfate polymer-filled capillary gel electrophoresis (CE-SDS) meat protein profiles for the identification of meat species. The specific objectives were 1) to collect quantitative data on water-soluble and saline-soluble proteins of different meat species obtained by CE-SDS and 2) to apply LDA on collected CE-SDS protein data for the development of a pattern recognition statistical model useful in the differentiation of meat species. Samples were raw beef top and eye round, boneless fresh pork ham and loin, turkey leg and breast meat, and mechanically deboned turkey meat collected on six different occasions, making a total of 42 samples. Additionally, 14 samples were used as test samples to determine the classification ability of the procedure. Quantitative protein data obtained by CE-SDS was used to generate separate LDA models for either water- or saline-soluble protein extracts. Although a saline solution was a more efficient meat protein-extracting agent, as shown by a higher total protein concentration and a larger number of peaks, water-soluble CE-SDS protein profiles gave more distinctive discrimination among meat species. The correct classification given by LDA on water-soluble protein data was 100% for all meat species, except pork (94%). Conversely, the correct classification on saline-soluble protein data was 88% for beef and mechanically deboned turkey meat, and 94% and 100% for turkey and pork meat, respectively. LDA proved to be a useful pattern recognition procedure in the interpretation of CE-SDS protein profiles for the identification of meat species.

A new procedure for coating capillaries for capillary electrophoresis applying a sapphire (alumina) containing epoxy resin was developed. Coated capillaries showed considerably reduced electroosmotic flow, and decreased the adsorption of proteins to the internal wall of the capillary. Coating is transparent down to 195 nm and can be used with advantage to analyze different kinds of substances, such as small cations and/or anions, and proteins.

The potential of micellar electrokinetic chromatography (MEKC) for the profiling of cocaine samples is described. An MEKC system containing sodium dodecyl sulfate (SDS) and methanol was optimized using a test mixture of cocaine, its common impurities (benzoylecgonine, norcocaine, tropacocaine, and trans-cinnamoylcocaine), and several degradation products. The effect of pH, percentage modifier, and concentration surfactant on the separation has been investigated. The optimal separation buffer for cocaine samples consisted of 75 mM SDS, 17.5% methanol, and 25 mM borate (pH 8.3) and was well suited to separate components of diverse polarity in one run. Various cocaine seizures have been analyzed with the MEKC system and their signatures were compared. The electrokinetic chromatograms obtained were characteristic, and differences and similarities among the samples could easily be observed. Several impurities were identified in the samples by means of migration times and comparison of recorded and library UV spectra. The composition of the samples was determined semiquantitatively using relative corrected peak areas.

A new capillary electrophoresis method to determine simultaneously eight of the most important anti-Parkinson's disease compounds has been developed. The generic names of the drugs studied are benactyzine (BA), trihexyphenidyl (TP), fenpiverin (FP), diphemin (DF), scopolamine (BL), adiphenine (TS), diethylaminoethylester 1-phenylcyclopentane-1-carboxylate (EKK), and diethylaminoethylester tetramethoxydiphenylacetate (EKO). An untreated fused-silica capillary tube (75 microns i.d., 57 cm total length, 49.5 cm length to the detector) was used with detection at 190 nm. The optimal separation conditions were 50 mM phosphate buffer (pH 2.7) with 7 mM-beta-cyclodextrin, electrokinetic injection for 15 sec at 5 kV, temperature 25 degrees C, and 15-20 kV separation voltage. Complete separation of all compounds was achieved in less than 16 min. The procedure was applied for the determination in urine and serum. The limits of detection (LOD, S/N = 3) for serum were 209 (FP), 234 (EKO), 168 (DF), 182 (BA), 168 (TP), 220 (BL), 174 (TS), and 163 (EKK) ppb. The method can be used for the therapeutic drug monitoring of these central active cholinolytics in clinical laboratories.

Enantiomers of bioactive molecules often differ in potency, toxicity, metabolism, and pharmacological actions. Capillary electrochromatography (CEC) is an emerging separation technique being investigated for use in chiral separations. CEC is a hybrid of HPLC and CE. CEC combines the electrophoretic mobility of CE with the partitioning mechanisms of HPLC. In this overview, several resolution mechanisms commonly used in CEC and the main parameters influencing the selectivity of the chiral separation will be discussed. Current applications of CEC in chiral separations of pharmaceuticals will be provided for each type of resolution mechanism. Finally, the advantages and limitations of CEC will be described, followed by the future outlook for CEC.

A cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) method has been developed and validated for purity determination of two bile acids, ursodeoxycholic acid (UDCA) and deoxycholic acid (DCA). Quantitation of related impurities such as lithocholic acid (LCA), chenodeoxycholic acid (CDCA), cholic acid (CA), and DCA in UDCA and CA in DCA was performed. A running buffer containing 20 mM borate-phosphate, 50 mM sodium dodecyl sulfate (SDS), 2.0 mM beta-cyclodextrin, and acetonitrile was used. Modifiers were added to improve resolution and selectivity. The applied voltage was 25 kV and detection was performed at 185 nm. Validation parameters such as selectivity, linearity, repeatability, intermediate precision, limit of detection, limit of quantitation, and robustness were evaluated. The method was simple and proved to be useful for the purity testing of bile acids in bulk drugs. Good results were obtained for related impurities at concentration levels from 0.05 to 1.5% with respect to the main component, according to international requirements.

The general objective of this study was to utilize chemometrics in the interpretation of capillary electrophoresis milk protein profiles, for the detection of pasteurized milk adulteration with rehydrated milk powder or a rehydrated dairy-based milk substitute. The specific objectives were 1) to collect quantitative data on major casein and whey proteins in authentic and adulterated milks in a single CE analysis; and 2) to apply a pattern recognition procedure, Soft Independent Modeling of Class Analogies (SIMCA), on collected CE protein data, for the development of a statistical model useful in the detection of pasteurized milk adulteration. Authentic samples were fresh milk collected from various farms over a period of six months. Adulterated samples were authentic fresh milk partially or totally substituted with rehydrated milk powder or a rehydrated commercial milk substitute at different levels. Quantitative protein data obtained by capillary free zone electrophoresis for beta-lactoglobulin, alpha-lactalbumin, beta-casein, and alpha-casein of 86 samples, authentic and adulterated samples, were used as a training set to build a SIMCA multivariate statistical model. The detection of sample outliers was useful for the elimination of unusual samples and optimization of the multivariate model. From the 35 commercial pasteurized milks tested, which were treated as unknowns, a total of 14 samples (40%) were not assigned to the authentic or fresh milk group, meaning that these samples had some type of adulteration at the levels included in the training set (> 15%). Decision-making on detecting adulteration of unknown commercial pasteurized milk samples was eased since predictions were based on statistical probabilities.

The use of capillary electrophoresis (CE) as an alternative to existing methods of quantitation of carbon monoxide (CO) in hemoglobin from postmortem blood samples is presented. The isolation of heme (the portion of the hemoglobin molecule in which CO binding takes place) from hemoglobin is described. Reduced (containing no gas molecules) heme and CO-heme isolated from hemoglobin standards were successfully separated using CE. Heme and CO-heme were also isolated from blood samples of accident victims and analyzed using CE. A quantifiable difference in the CO-heme signals from blood samples containing fatal and nonfatal levels of CO was observed.

A method for the rapid analysis of low-molecular-mass anions in electrodeposition coatings has been developed, employing capillary electrophoresis with a nonsuppressed end-capillary conductivity detector. After optimization of the carrier electrolyte, quantitative determination of all analytes of interest (including inorganic anions and organic acids) was possible in less than 11 min. The results obtained by capillary electrophoresis did not show any significant differences with the manufacturer's data originating from the more time-consuming ion-chromatographic analysis.