Capillary electrophoresis vitamins

Analytical methods are ripe for attack using Al methods. Capillary electrophoresis is a routine separation technique, but like other separation techniques, its effectiveness is correlated strongly with experimental conditions. Hence it is important to optimize experimental conditions to achieve the maximum degree of separation. Zhang and co-workers41 studied the separation of mixtures in reserpine tablets, in which vitamin B1 and dibazolum may be incompletely separated, as may promethazine hydrochloride and chloroquine... 

Nonaqueous capillary electrophoresis is a new technique that matured over the last couple of years to complement the electrophoretic techniques performed under aqueous conditions. Consequently, it extends the applicability of CE to those analytes that are insoluble or only sparsely soluble in water, including several classes of pharmaceutical compounds and long-chain fatty acids, vitamins, and surfactants, to name only a few. 

Several different techniques have been proposed for vitamin B12 determination, such as microbiological assay, spectrophotometry, chemiluminescence, atomic absorption spectrometry, capillary electrophoresis, and HPLC. 

Table 30 Capillary Electrophoresis Methods for Quantitating Vitamin C (UV Absorbance Detection)... 

EV Koh, MG Bissell, RK Ito. Measurement of vitamin C by capillary electrophoresis in biological fluids and fruit beverages using a stereoisomer as an internal standard. J Chromatogr 633 245-250, 1993. 

Ascorbic acid is an important vitamin and its determination is needed not only in foods but also in drugs, blood and urine. Capillary electrophoresis microchips with EC detection allow a simple and rapid detection of ascorbic acid as well as its separation from interferences. 

D. Lambert, C. Adjalla, F. Felden, S. Benhayoun, J. P. Nicolas, and J. L. Gueant, Identification of vitamin B12 and analogues by high-performance capillary electrophoresis and comparison with high-performance liquid chromatography, J. Chromatogr., 608 311 (1992). 

L Fotsing, M Fillet, I Bechet, P Hubert, J Crommen. Determination of six water-soluble vitamins in a pharmaceutical formulation by capillary electrophoresis. J Pharm Biomed Anal 15 1113-1123, 1997. 

L Fotsing, B Boulanger, P Chiap, M Fillet, P Hubert, J Crommen. Multivariate optimization approach for the separation of water-soluble vitamins and related compounds by capillary electrophoresis. Biomed Chromatogr 14 10-11, 2000. 

B Yang, J Mo, X Yang, L Wang. Separation and determination of chlorphenamine maleate, acetaminophen and vitamin C of cold medicines by capillary electrophoresis with amperometric detection. Sepu 17 477-479, 1999. 

The interesting combination of capillary electrophoresis-X-ray fluorescence detection was recently described as an element-specific detector [136]. A special plastic cell, which was both X-ray transparent and did not produce any interfering emission, was used. Vitamin B-12 (cyanocobalamin) and the cyclohexanediaminotetraacetic acid complexes of iron, zinc, cobalt, and copper were separated. Although the detection limits found were in the nanogram range, the authors estimate that with optimization that 2 or 3 orders of magnitude more sensitivity is likely. 

Craige Trenerry, V., The application of capillary electrophoresis to the analysis of vitamins in food and beverages. Electrophoresis, 22, 1468, 2001. 

Law, W. S., Kuban, R, Hong Zhao, J., Li, S. F. Y, and Hauser, P. C., Determination of vitamin C and preservatives in beverages by conventional capillary electrophoresis and microchip electrophoresis with capacitively coupled eontactless eonductivity detection, Flectrophoresis, 26, 4648, 2005. 

The solute species in the sample solution is concentrated in the sedimented phase, and a 100-1000-fold increase in concentration is achieved. This method is used to concentrate vital compounds such as hemoglobin, vitamin B12, and various metal ions. HLLE seems to be a simple and powerful preconcentration method for several instrumentation techniques, including capillary gas chromatography and capillary electrophoresis. 

Capillary electrophoresis can be used instead of HPLC for separation of complex samples, but has not yet found a broader application in vitamin analysis. Gas chromatography is rarely used as most vitamins are not volatile or stable enough for direct analysis. Applications include determination of vitamin D after derivatiztion. 

In addition to chromatographic techniques, several methods have been used for the determination and analysis of vitamins in different samples, such as immunoassays [34] and electrochemical [6] and capillary electrophoresis [39],... 

Capillary electrophoresis (CE) is the fastest growing separation science technique today for the separation and quantitation of peptides and proteins.(lX2) For these biomolecules, the high separation efficiency coupled with the small sample requirements, ease of automation, and the possibility of direct quantitation has placed CE in the forefront of bioanalytical techniques complementing traditional slab gel electrophoresis and liquid chromatography.(3)(4)(5) CE analyses of all the following species have been reported amino acids, peptides, proteins, ions, enantiomers, PCR products, DNA, nucleotides, vitamins, pharmaceuticals, aromatic hydrocarbons, explosive constituents, isoforms, immunoglobulins and dilute biological solutions. (6)(7)... 

Crevillen, A.G., Pumera, M., Gonzalez, M.C., and Escarpa, A. (2008) Carbon nanotubes disposable detectors in microchip capillary electrophoresis for water-soluble vitamins determination analytical possibilities in pharmaceutical quality control. 

The work covers both the fat-soluble (Chapters 1—4) and the water-soluble (Chapters 5-13) vitamins, with emphasis on state-of-the-art chromatography, sample preparation, and final measurement. Following present analytical evolution, sections on recent techniques such as capillary electrophoresis and mass spectrometry have been added or expanded. Information on metabolism and biochemical function has also been revised to incorporate current knowledge. 

H Shi, Y Ma, JH Humphrey, NE Craft. Determination of vitamin A in dried human blood spots by high-performance capillary electrophoresis with laser-excited fluorescence detection. J Chromatogr B Biomed Appl 665 89-96, 1995. 

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