A method was established to monitor organic reactions by micellar capillary electrokinetic chromatography (MEKC). After optimizing conditions such as the composition of the solvents, the surfactant, and the apparent pH (pH*) of the system, the method was utilized to analyze the reaction of glycidyl methacrylate (GMA) and allyl amine. The main products were identified in the electropherograms. The reaction procedure was monitored in real time. This method was found to have common applicability, being able to separate and detect nonaqueous soluble, nonionic, and low-UV-Vis absorbance compounds. It provides a rapid and low-cost way to understand organic reactions and to direct synthesis works. 1. Introduction Capillary electrophoresis (CE) is a rapid and high-performance method of separation and analysis [1]. It possesses advantages such as high efficiency, high speed, ease to be automated, low sample consumption, low cost, and multimode availability. After decades of development, CE plays important roles in the fields of chemistry, biology, pharmaceutical, environment, toxicology, medicine, and forensic chemistry [2–10]. It is very important to analyze the products of an organic reaction, as well as to monitor the related kinetics or reaction procedure. The related methods are mainly focused on elemental analysis, nuclear magnetic resonance (NMR), mass spectrometry (MS), infrared radiation (IR), and ultraviolet visible (UV-Vis) spectrometry. Many of these methods are usually obstructed by the limited purification of the products from complex reactions. A chromatographic method (gas or liquid) can be used to simultaneously separate and detect complex samples. It enables the analysis and monitoring of organic reactions in real time [11]. CE is a method which can analyze charged analytes in aqueous solution. CE could also be an important method to analyze chemical reactions, playing a role in the research of reaction kinetics [5, 12], asymmetric transformation of amino acids [13, 14], catalytic oxidation [15], assembling of nanoparticles [16], protein interaction [17], and polymerase chain reaction (PCR) [18–20]. One of the modes of CE, micellar electrokinetic chromatography (MEKC), introduced surfactants as pseudostationary phases. In such a CE operation, analytes are not only separated in accordance with their mobility but also based on their distributions in the pseudostationary phases. As a result, neutral compounds without any charge could also be separated in that case when they appear in different concentrations in the micelle. In this paper, we give
References
[1]
S. Hjertén, “High-performance electrophoresis: the electrophoretic counterpart of high-performance liquid chromatography,” Journal of Chromatography A, vol. 270, pp. 1–6, 1983.
[2]
J. H. Xiong, W. B. Zhang, G. W. Xu, and Y. K. Zhang, “Advances in nonaqueous capillary electrophoresis,” Chinese Journal of Chromatography, vol. 18, no. 3, pp. 218–223, 2000.
[3]
J. Stocks and N. E. Miller, “Capillary electrophoresis to monitor the oxidative modification of low density lipoproteins,” Journal of Lipid Research, vol. 39, no. 6, pp. 1305–1309, 1998.
[4]
P. F. G. De Sa, J. M. Treubig Jr., P. R. Brown, and J. A. Dain, “The use of capillary electrophoresis to monitor Maillard reaction products (MRP) by glyceraldehyde and the epsilon amino group of lysine,” Food Chemistry, vol. 72, no. 3, pp. 379–384, 2001.
[5]
M. Vaher, S. Ehala, and M. Kaljurand, “On-column capillary electrophoretic monitoring of rapid reaction kinetics for determination of the antioxidative potential of various bioactive phenols,” Electrophoresis, vol. 26, no. 4-5, pp. 990–1000, 2005.
[6]
X. Sun, W. Jin, D. Li, and Z. Bai, “Measurement of alkaline phosphatase isoenzymes in individual mouse bone marrow fibroblast cells based on capillary electrophoresis with on-capillary enzyme-catalyzed reaction and electrochemical detection,” Electrophoresis, vol. 25, no. 12, pp. 1860–1866, 2004.
[7]
J. Pédron, R. Maldiney, M. Brault, and E. Miginiac, “Monitoring of hapten-protein coupling reactions by capillary zone electrophoresis: improvement of abscisic acid-bovine serum albumin coupling and determination of molar coupling ratios,” Journal of Chromatography A, vol. 723, no. 2, pp. 381–388, 1996.
[8]
J. K. Cheng, W. H. Huang, and Z. L. Wang, “Studies on single-cell analysis,” Chinese Journal of Chromatography, vol. 25, no. 1, pp. 1–10, 2007.
[9]
H. F. Zou and X. D. Huang, “Separation and Determination of Biomolecules,” Chinese Journal of Chromatography, vol. 21, no. 4, pp. 311–315, 2003.
[10]
F. Carlucci, A. Tabucchi, A. Aiuti, et al., “Capillary electrophoresis in diagnosis and monitoring of adenosine deaminase deficiency,” Clinical Chemistry, vol. 49, no. 11, pp. 1830–1838, 2003.
[11]
L. A. Hammad, M. M. Saleh, M. V. Novotny, and Y. Mechref, “Multiple-reaction monitoring liquid chromatography mass spectrometry for monosaccharide compositional analysis of glycoproteins,” Journal of the American Society for Mass Spectrometry, vol. 20, no. 6, pp. 1224–1234, 2009.
[12]
M. Kulp, M. Vaher, and M. Kaljurand, “Miniaturization of sampling for chemical reaction monitoring by capillary electrophoresis,” Journal of Chromatography A, vol. 1100, no. 1, pp. 126–129, 2005.
[13]
A. Schuchert-Shi, P. Kubáň, and P. C. Hauser, “Monitoring of enzymatic reactions using conventional and on-chip capillary electrophoresis with contactless conductivity detection,” Electrophoresis, vol. 28, no. 24, pp. 4690–4696, 2007.
[14]
J. Wang, K. Liu, G. Sun, J. Bai, and L. Wang, “Capillary array electrophoresis for the research of asymmetric transformation reaction of L-proline to D-proline,” Journal of Separation Science, vol. 28, no. 18, pp. 2551–2554, 2005.
[15]
T. Yamashiro and T. Okado, “Capillary electrophoresis as a nanoreactor of separation capability: on-capillary reaction catalyzed by transition metal ions,” Electrophoresis, vol. 24, no. 12-13, pp. 2168–2173, 2003.
[16]
Q. Liu, L. Yao, Q. Shen, Z. Nie, M. Guo, and S. Yao, “Layer-by-layer assembly of polyelectrolyte and nanoparticles, monitored by capillary electrophoresis,” Chemistry, vol. 15, no. 46, pp. 12828–12836, 2009.
[17]
J. Pédron, R. Maldiney, M. Brault, and E. Miginiac, “Monitoring of hapten-protein coupling reactions by capillary zone electrophoresis: improvement of abscisic acid-bovine serum albumin coupling and determination of molar coupling ratios,” Journal of Chromatography A, vol. 723, no. 2, pp. 381–388, 1996.
[18]
J. B. Stevenson, W. C. Hymas, and D. R. Hillyard, “A novel capillary electrophoresis-based multiplex PCR assay for detection of respiratory pathogens,” Annals of Clinical & Laboratory Science, vol. 41, no. 1, pp. 33–38, 2011.
[19]
C. S. Zhang, D. Xing, and Y. Y. Li, “Applications of laser technique for polymerase chain reaction microfluic chips,” Chinese Journal of Analytical Chemistry, vol. 36, pp. 259–265, 2008.
[20]
A. T. Woolley, D. Hadley, P. Landre, A. J. DeMello, R. A. Mathies, and M. A. Northrup, “Functional integration of PCR amplification and capillary electrophoresis in a microfabricated DNA analysis device,” Analytical Chemistry, vol. 68, no. 23, pp. 4081–4086, 1996.
[21]
R. S. Sahota and M. G. Khaledi, “Nonaqueous capillary electrophoresis,” Analytical Chemistry, vol. 66, no. 7, pp. 1141–1146, 1994.