Preparation of cellulose-graft-polymethacrylic acid nanocapsule encapsulating gallic acid for cosmetic application
Article Sidebar
Published:
Dec 20, 2018
Keywords:
carboxymethyl cellulose polymethacrylic acid gallic acid miniemulsion polymerization
Main Article Content
Abstract
In this research, the preparation of cellulose nanocapsules encapsulating gallic acid (GA), an important component in Bambara groundnut extracts, by water in oil miniemulsion polymerization was studied using carboxymethyl cellulose (CMC) as a shell. Initially, CMC was modified with 3-(trimethoxysilyl)propyl methacrylate (MPS) as a silane coupling agent at a ratio of CMC:MPS of 75:25 (%w/w). The FT-IR results confirmed the successful modification of CMC. The C=C bonds from silane coupling agent were observed in m-CMC spectrum which were further polymerized with methacrylic acid (MAA) monomer to form 3D-network CMC-graft-polymethacrylic acid shell. Various ratios of m-CMC:MAA and stirring rate for monomer droplet preparation were investigated. It was found that the optimum condition was a m-CMC:MAA at 33:67 and 40% amplitude, respectively. The obtained nanocapsules presented high colloidal stability, spherical shape and nano-sized with high loading and encapsulation efficiency at 24 and 73%, respectively.
Article Details
How to Cite
1.
Tangsongcharoen W, Punyamoonwongsa P, Chaiyasat A, Chaiyasat P. Preparation of cellulose-graft-polymethacrylic acid nanocapsule encapsulating gallic acid for cosmetic application. J Appl Res Sci Tech [Internet]. 2018 Dec. 20 [cited 2024 Apr. 20];17(2):23-40. Available from: https://ph01.tci-thaijo.org/index.php/rmutt-journal/article/view/157101
Section
Research Articles
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
References
[1] A. G. P. Mongomake´ Kone´, Yaya Toure´. (2011). Bambara Groundnut [Vigna subterranea (L.) Verdc. (Fabaceae)] Usage in Human Health. Nuts & Seeds in Health and Disease Prevention, 189-196.
[2] Y. Y. Murevanhema and V. A. Jideani. (2013). Potential of Bambara Groundnut (Vigna subterranea (L.) Verdc) Milk as a Probiotic Beverage—A Review. Critical Reviews in Food Science and Nutrition, 53 (9), 954-967.
[3] V. K. Rajan and K. Muraleedharan. (2017). A computational investigation on the structure, global parameters and antioxidant capacity of a polyphenol, Gallic acid. Food Chemistry, 220, 93-99.
[4] R. Costa and L. Santos. (2017). Delivery systems for cosmetics - From manufacturing to the skin of natural antioxidants. Powder Technology, 322, 402-416.
[5] K. Thammarat, Leena, N., Punnanee, S. and Soottawat, B., (2015). Functional and Antioxidative properties of Bambara groundnut (Voandzeia subterranea) protein hydrolysates. International Food Research Journal, 22 (4), 1584-1595.
[6] K. Thammarat, Leena, N., Punnanee, S. and Soottawat, B., (2015). Chemical Composition, Functional and Antioxidative Properties of Protein Hydrolysate from Bambara Groundnut (Voandzeia subterranea). International Food Research Journal, 22 (4), 1584-1595.
[7] O. M. Ogundele and M. N. Emmambux. (2018). Effect of infrared heating of pre-soaked whole and dehulled bambara groundnut (Vigna subterranea) seeds on their cooking characteristics and microstructure. LWT, 97, 581-587.
[8] A. E. Unigwe, E. Doria, P. Adebola, A. S. Gerrano, and M. Pillay. (2018). Anti-nutrient analysis of 30 Bambara groundnut (Vigna subterranea) accessions in South Africa. Journal of Crop Improvement, 32 (2), 208-224.
[9] S.O SALAWU. (2016). COMPARATIVE STUDY OF THE ANTIOXIDANT ACTIVITIES OF METHANOLIC EXTRACT AND SIMULATED GASTROINTESTINAL ENZYME DIGEST OF BAMBARA NUT (Vigna subterranean). FUTA Journal of Research in Sciences, 1, 107-120.
[10] T. Harris, V. Jideani, and M. Le Roes-Hill. (2018). Flavonoids and tannin composition of Bambara groundnut (Vigna subterranea) of Mpumalanga, South Africa. Heliyon, 4 (9), e00833.
[11] J. Li, S. Y. Kim, X. Chen, and H. J. Park. (2016). Calcium-alginate beads loaded with gallic acid: Preparation and characterization. LWT - Food Science and Technology, 68, 667-673.
[12] A. de Cristo Soares Alves, R. M. Mainardes, and N. M. Khalil. (2016). Nanoencapsulation of gallic acid and evaluation of its cytotoxicity and antioxidant activity. Materials Science and Engineering: C, 60, 126-134.
[13] A. Gomes, A. L. R. Costa, F. de Assis Perrechil, and R. L. da Cunha. (2016). Role of the phases composition on the incorporation of gallic acid in O/W and W/O emulsions. Journal of Food Engineering, 168, 205-214.
[14] P. Chaiyasat, M. Z. Islam, and A. Chaiyasat. (2013). Preparation of poly(divinylbenzene) microencapsulated octadecane by microsuspension polymerization: oil droplets generated by phase inversion emulsification. RSC Advances, 3, (26), 10202-10207.
[15] A. Luca, B. Cilek, V. Hasirci, S. Sahin, and G. Sumnu. (2013). Effect of Degritting of Phenolic Extract from Sour Cherry Pomace on Encapsulation Efficiency—Production of Nano-suspension. Food and Bioprocess Technology, 6 (9), 2494-2502.
[16] B. Cilek, A. Luca, V. Hasirci, S. Sahin, and G. Sumnu. (2012). Microencapsulation of phenolic compounds extracted from sour cherry pomace: effect of formulation, ultrasonication time and core to coating ratio. European Food Research and Technology, 235 (4), 587-596.
[17] P. Laine, P. Kylli, M. Heinonen, and K. Jouppila. (2008). Storage Stability of Microencapsulated Cloudberry (Rubus chamaemorus) Phenolics. Journal of Agricultural and Food Chemistry, 56 (23), 11251-11261.
[18] R. Dubey. (2009). "Microencapsulation Technology and Applications," 2009, Microencapsulation technology, microcapsule, release mechanisms, pharmaceuticals, polymers, stabilizers, emulsion, 59 (1), 14.
[19] S. Gouin. (2004). Microencapsulation: industrial appraisal of existing technologies and trends. Trends in Food Science & Technology, 15 (7), 330-347.
[20] I. S. Santos, B. M. Ponte, P. Boonme, A. M. Silva, and E. B. Souto. (2013). Nanoencapsulation of polyphenols for protective effect against colon–rectal cancer. Biotechnology Advances, 31 (5), 514-523.
[21] F. Pinto, D. P. C. de Barros, and L. P. Fonseca. (2018). Design of multifunctional nanostructured lipid carriers enriched with α-tocopherol using vegetable oils. Industrial Crops and Products, 118, 149-159.
[22] S. Serieye, F. Méducin, A. Tidu, and S. Guillot. (2018). Incorporation of aromas in nanostructured monolinolein-based miniemulsions: A structural investigation. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 555, 802-808.
[23] P. E. Feuser et al.. (2015). Simultaneous encapsulation of magnetic nanoparticles and zinc phthalocyanine in poly(methyl methacrylate) nanoparticles by miniemulsion polymerization and in vitro studies. Colloids and Surfaces B: Biointerfaces, 135, 357-364.
[24] F. Schué. (2000). Biopolymers from renewable resources. Edited by D L Kaplan Springer-Verlag. Heidelberg, 1998. Polymer International, 49 (5), 472-473.
[25] A. n. J. V. M. Florentina Adriana Cziple. (2008). Biopolymers Versus Synthetic Polymers. Anul XV, 1, 125-132.
[26] S. M. Ali and G. Yosipovitch. (2013). Skin pH: from basic science to basic skin care. (in eng), Acta Derm Venereol, 93 (3), 261-269(9).
[27] S. Barkhordari and M. Yadollahi. (2016). Carboxymethyl cellulose capsulated layered double hydroxides/drug nanohybrids for Cephalexin oral delivery. Applied Clay Science, 121-122, 77-85.
[28] S. Butun, F. G. Ince, H. Erdugan, and N. Sahiner. (2011). One-step fabrication of biocompatible carboxymethyl cellulose polymeric particles for drug delivery systems. Carbohydrate Polymers, 86 (2), 636-643.
[29] C. D. a. M. M. Alessandro Sannino. (2009). Biodegradable Cellulose-based Hydrogels: Design and Applications. Materials, 2, 353-373.
[30] H. A.-Y., A. M. Adel, A.A. El-Gendy and A.M. Nada. (2010). Carboxymethylated Cellulose Hydrogel; Sorption Behavior and Characterization. Nature and Science, 8, (8), 244-256.
[31] A. Sannino et al.. (2004). Cellulose Derivative−Hyaluronic Acid-Based Microporous Hydrogels Cross-Linked through Divinyl Sulfone (DVS) To Modulate Equilibrium Sorption Capacity and Network Stability. Biomacromolecules, 5 (1), 92-96.
[32] C. Demitri, F. Scalera, M. Madaghiele, A. Sannino, and A. Maffezzoli. (2013). Potential of Cellulose-Based Superabsorbent Hydrogels as Water Reservoir in Agriculture. International Journal of Polymer Science, 2013, 6.
[33] A. A. Hebeish, M. H. El-Rafie, F. A. Abdel-Mohdy, E. S. Abdel-Halim, and H. E. Emam. (2010). Carboxymethyl cellulose for green synthesis and stabilization of silver nanoparticles. Carbohydrate Polymers, 82 (3), 933-941.
[34] E. S. Abdel-Halim, H. H. Alanazi, and S. S. Al-Deyab. (2015). Utilization of hydroxypropyl carboxymethyl cellulose in synthesis of silver nanoparticles. International Journal of Biological Macromolecules, 75, 467-473.
[35] E. Duhoranimana et al.. (2018). Thermodynamic characterization of Gelatin–Sodium carboxymethyl cellulose complex coacervation encapsulating Conjugated Linoleic Acid (CLA). Food Hydrocolloids, 80, 149-159.
[36] H. Koga, T. Kitaoka, and A. Isogai. (2015). Chemically-Modified Cellulose Paper as a Microstructured Catalytic Reactor. Molecules, 20 (1), 1495-1508.
[37] H. Koga, T. Kitaoka, and A. Isogai. (2011). In situ modification of cellulose paper with amino groups for catalytic applications. Journal of Materials Chemistry, 21 (25), 9356-9361.
[38] M. Abdelmouleh, S. Boufi, A. ben Salah, M. N. Belgacem, and A. Gandini. (2002). Interaction of Silane Coupling Agents with Cellulose. Langmuir, 18 (8), 3203-3208.
[39] M. Abdmouleh, S. Boufi, N. Belgacem, A. Dufresne, and A. Gandini. (2005). Modification of cellulose fibers with functionalized silanes: Effect of the fiber treatment on the mechanical performances of cellulose-thermoset composites. Journal of Applied Polymer Science, 98 (3), 974-984.
[40] M.-C. Brochier Salon, M. Abdelmouleh, S. Boufi, M. N. Belgacem, and A. Gandini. (2005). Silane adsorption onto cellulose fibers: Hydrolysis and condensation reactions. Journal of Colloid and Interface Science, 289 (1), 249-261.
[41] R. K. G. Manju Kumari Thakura, Vijay Kumar Thakurc. (2014). Surface modification of cellulose using silane coupling agent. Carbohydrate Polymers, 111, 849-855.
[42] M.-C. Brochier Salon and M. N. Belgacem. (2011). Hydrolysis-Condensation Kinetics of Different Silane Coupling Agents. Phosphorus, Sulfur, and Silicon and the Related Elements, 186 (2), 240-254.
[43] H. Koga, T. Kitaoka, and A. Isogai. (2012). Paper-immobilized enzyme as a green microstructured catalyst. Journal of Materials Chemistry, 22 (23), 11591-11597.
[44] Y. Xie, C. A. S. Hill, Z. Xiao, H. Militz, and C. Mai. (2010). Silane coupling agents used for natural fiber/polymer composites: A review. Composites Part A: Applied Science and Manufacturing, 41 (7), 806-819.
[45] V. Kozlovskaya, E. Kharlampieva, M. L. Mansfield, and S. A. Sukhishvili. (2006). Poly(methacrylic acid) Hydrogel Films and Capsules: Response to pH and Ionic Strength, and Encapsulation of Macromolecules. Chemistry of Materials, 18 (2), 328-336.
[46] A. D. Susheel Kalia, Bibin Mathew Cherian, B. S. Kaith, Luc Ave ́rous, James Njuguna, and Elias Nassiopoulos. Cellulose-Based Bio- and Nanocomposites: A Review. International Journal of Polymer Science, 2011, 1-36.
[47] D. Dorniani, M. Z. B. Hussein, A. U. Kura, S. Fakurazi, A. H. Shaari, and Z. Ahmad. (2012). Preparation of Fe₃O₄ magnetic nanoparticles coated with gallic acid for drug delivery. International journal of nanomedicine, 7, 5745-5756.
[48] O. M. Medvedeva, V. S. Kurakina, S. G. Dmitrienko, T. I. Tikhomirova, and O. A. Shpigun. (2004). Separation and Determination of Phenolcarboxylic Acids by Capillary Zone Electrophoresis with Dynamic Preconcentration on Hypercrosslinked Polystyrene. Journal of Analytical Chemistry, 59 (7), 669-676.
[2] Y. Y. Murevanhema and V. A. Jideani. (2013). Potential of Bambara Groundnut (Vigna subterranea (L.) Verdc) Milk as a Probiotic Beverage—A Review. Critical Reviews in Food Science and Nutrition, 53 (9), 954-967.
[3] V. K. Rajan and K. Muraleedharan. (2017). A computational investigation on the structure, global parameters and antioxidant capacity of a polyphenol, Gallic acid. Food Chemistry, 220, 93-99.
[4] R. Costa and L. Santos. (2017). Delivery systems for cosmetics - From manufacturing to the skin of natural antioxidants. Powder Technology, 322, 402-416.
[5] K. Thammarat, Leena, N., Punnanee, S. and Soottawat, B., (2015). Functional and Antioxidative properties of Bambara groundnut (Voandzeia subterranea) protein hydrolysates. International Food Research Journal, 22 (4), 1584-1595.
[6] K. Thammarat, Leena, N., Punnanee, S. and Soottawat, B., (2015). Chemical Composition, Functional and Antioxidative Properties of Protein Hydrolysate from Bambara Groundnut (Voandzeia subterranea). International Food Research Journal, 22 (4), 1584-1595.
[7] O. M. Ogundele and M. N. Emmambux. (2018). Effect of infrared heating of pre-soaked whole and dehulled bambara groundnut (Vigna subterranea) seeds on their cooking characteristics and microstructure. LWT, 97, 581-587.
[8] A. E. Unigwe, E. Doria, P. Adebola, A. S. Gerrano, and M. Pillay. (2018). Anti-nutrient analysis of 30 Bambara groundnut (Vigna subterranea) accessions in South Africa. Journal of Crop Improvement, 32 (2), 208-224.
[9] S.O SALAWU. (2016). COMPARATIVE STUDY OF THE ANTIOXIDANT ACTIVITIES OF METHANOLIC EXTRACT AND SIMULATED GASTROINTESTINAL ENZYME DIGEST OF BAMBARA NUT (Vigna subterranean). FUTA Journal of Research in Sciences, 1, 107-120.
[10] T. Harris, V. Jideani, and M. Le Roes-Hill. (2018). Flavonoids and tannin composition of Bambara groundnut (Vigna subterranea) of Mpumalanga, South Africa. Heliyon, 4 (9), e00833.
[11] J. Li, S. Y. Kim, X. Chen, and H. J. Park. (2016). Calcium-alginate beads loaded with gallic acid: Preparation and characterization. LWT - Food Science and Technology, 68, 667-673.
[12] A. de Cristo Soares Alves, R. M. Mainardes, and N. M. Khalil. (2016). Nanoencapsulation of gallic acid and evaluation of its cytotoxicity and antioxidant activity. Materials Science and Engineering: C, 60, 126-134.
[13] A. Gomes, A. L. R. Costa, F. de Assis Perrechil, and R. L. da Cunha. (2016). Role of the phases composition on the incorporation of gallic acid in O/W and W/O emulsions. Journal of Food Engineering, 168, 205-214.
[14] P. Chaiyasat, M. Z. Islam, and A. Chaiyasat. (2013). Preparation of poly(divinylbenzene) microencapsulated octadecane by microsuspension polymerization: oil droplets generated by phase inversion emulsification. RSC Advances, 3, (26), 10202-10207.
[15] A. Luca, B. Cilek, V. Hasirci, S. Sahin, and G. Sumnu. (2013). Effect of Degritting of Phenolic Extract from Sour Cherry Pomace on Encapsulation Efficiency—Production of Nano-suspension. Food and Bioprocess Technology, 6 (9), 2494-2502.
[16] B. Cilek, A. Luca, V. Hasirci, S. Sahin, and G. Sumnu. (2012). Microencapsulation of phenolic compounds extracted from sour cherry pomace: effect of formulation, ultrasonication time and core to coating ratio. European Food Research and Technology, 235 (4), 587-596.
[17] P. Laine, P. Kylli, M. Heinonen, and K. Jouppila. (2008). Storage Stability of Microencapsulated Cloudberry (Rubus chamaemorus) Phenolics. Journal of Agricultural and Food Chemistry, 56 (23), 11251-11261.
[18] R. Dubey. (2009). "Microencapsulation Technology and Applications," 2009, Microencapsulation technology, microcapsule, release mechanisms, pharmaceuticals, polymers, stabilizers, emulsion, 59 (1), 14.
[19] S. Gouin. (2004). Microencapsulation: industrial appraisal of existing technologies and trends. Trends in Food Science & Technology, 15 (7), 330-347.
[20] I. S. Santos, B. M. Ponte, P. Boonme, A. M. Silva, and E. B. Souto. (2013). Nanoencapsulation of polyphenols for protective effect against colon–rectal cancer. Biotechnology Advances, 31 (5), 514-523.
[21] F. Pinto, D. P. C. de Barros, and L. P. Fonseca. (2018). Design of multifunctional nanostructured lipid carriers enriched with α-tocopherol using vegetable oils. Industrial Crops and Products, 118, 149-159.
[22] S. Serieye, F. Méducin, A. Tidu, and S. Guillot. (2018). Incorporation of aromas in nanostructured monolinolein-based miniemulsions: A structural investigation. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 555, 802-808.
[23] P. E. Feuser et al.. (2015). Simultaneous encapsulation of magnetic nanoparticles and zinc phthalocyanine in poly(methyl methacrylate) nanoparticles by miniemulsion polymerization and in vitro studies. Colloids and Surfaces B: Biointerfaces, 135, 357-364.
[24] F. Schué. (2000). Biopolymers from renewable resources. Edited by D L Kaplan Springer-Verlag. Heidelberg, 1998. Polymer International, 49 (5), 472-473.
[25] A. n. J. V. M. Florentina Adriana Cziple. (2008). Biopolymers Versus Synthetic Polymers. Anul XV, 1, 125-132.
[26] S. M. Ali and G. Yosipovitch. (2013). Skin pH: from basic science to basic skin care. (in eng), Acta Derm Venereol, 93 (3), 261-269(9).
[27] S. Barkhordari and M. Yadollahi. (2016). Carboxymethyl cellulose capsulated layered double hydroxides/drug nanohybrids for Cephalexin oral delivery. Applied Clay Science, 121-122, 77-85.
[28] S. Butun, F. G. Ince, H. Erdugan, and N. Sahiner. (2011). One-step fabrication of biocompatible carboxymethyl cellulose polymeric particles for drug delivery systems. Carbohydrate Polymers, 86 (2), 636-643.
[29] C. D. a. M. M. Alessandro Sannino. (2009). Biodegradable Cellulose-based Hydrogels: Design and Applications. Materials, 2, 353-373.
[30] H. A.-Y., A. M. Adel, A.A. El-Gendy and A.M. Nada. (2010). Carboxymethylated Cellulose Hydrogel; Sorption Behavior and Characterization. Nature and Science, 8, (8), 244-256.
[31] A. Sannino et al.. (2004). Cellulose Derivative−Hyaluronic Acid-Based Microporous Hydrogels Cross-Linked through Divinyl Sulfone (DVS) To Modulate Equilibrium Sorption Capacity and Network Stability. Biomacromolecules, 5 (1), 92-96.
[32] C. Demitri, F. Scalera, M. Madaghiele, A. Sannino, and A. Maffezzoli. (2013). Potential of Cellulose-Based Superabsorbent Hydrogels as Water Reservoir in Agriculture. International Journal of Polymer Science, 2013, 6.
[33] A. A. Hebeish, M. H. El-Rafie, F. A. Abdel-Mohdy, E. S. Abdel-Halim, and H. E. Emam. (2010). Carboxymethyl cellulose for green synthesis and stabilization of silver nanoparticles. Carbohydrate Polymers, 82 (3), 933-941.
[34] E. S. Abdel-Halim, H. H. Alanazi, and S. S. Al-Deyab. (2015). Utilization of hydroxypropyl carboxymethyl cellulose in synthesis of silver nanoparticles. International Journal of Biological Macromolecules, 75, 467-473.
[35] E. Duhoranimana et al.. (2018). Thermodynamic characterization of Gelatin–Sodium carboxymethyl cellulose complex coacervation encapsulating Conjugated Linoleic Acid (CLA). Food Hydrocolloids, 80, 149-159.
[36] H. Koga, T. Kitaoka, and A. Isogai. (2015). Chemically-Modified Cellulose Paper as a Microstructured Catalytic Reactor. Molecules, 20 (1), 1495-1508.
[37] H. Koga, T. Kitaoka, and A. Isogai. (2011). In situ modification of cellulose paper with amino groups for catalytic applications. Journal of Materials Chemistry, 21 (25), 9356-9361.
[38] M. Abdelmouleh, S. Boufi, A. ben Salah, M. N. Belgacem, and A. Gandini. (2002). Interaction of Silane Coupling Agents with Cellulose. Langmuir, 18 (8), 3203-3208.
[39] M. Abdmouleh, S. Boufi, N. Belgacem, A. Dufresne, and A. Gandini. (2005). Modification of cellulose fibers with functionalized silanes: Effect of the fiber treatment on the mechanical performances of cellulose-thermoset composites. Journal of Applied Polymer Science, 98 (3), 974-984.
[40] M.-C. Brochier Salon, M. Abdelmouleh, S. Boufi, M. N. Belgacem, and A. Gandini. (2005). Silane adsorption onto cellulose fibers: Hydrolysis and condensation reactions. Journal of Colloid and Interface Science, 289 (1), 249-261.
[41] R. K. G. Manju Kumari Thakura, Vijay Kumar Thakurc. (2014). Surface modification of cellulose using silane coupling agent. Carbohydrate Polymers, 111, 849-855.
[42] M.-C. Brochier Salon and M. N. Belgacem. (2011). Hydrolysis-Condensation Kinetics of Different Silane Coupling Agents. Phosphorus, Sulfur, and Silicon and the Related Elements, 186 (2), 240-254.
[43] H. Koga, T. Kitaoka, and A. Isogai. (2012). Paper-immobilized enzyme as a green microstructured catalyst. Journal of Materials Chemistry, 22 (23), 11591-11597.
[44] Y. Xie, C. A. S. Hill, Z. Xiao, H. Militz, and C. Mai. (2010). Silane coupling agents used for natural fiber/polymer composites: A review. Composites Part A: Applied Science and Manufacturing, 41 (7), 806-819.
[45] V. Kozlovskaya, E. Kharlampieva, M. L. Mansfield, and S. A. Sukhishvili. (2006). Poly(methacrylic acid) Hydrogel Films and Capsules: Response to pH and Ionic Strength, and Encapsulation of Macromolecules. Chemistry of Materials, 18 (2), 328-336.
[46] A. D. Susheel Kalia, Bibin Mathew Cherian, B. S. Kaith, Luc Ave ́rous, James Njuguna, and Elias Nassiopoulos. Cellulose-Based Bio- and Nanocomposites: A Review. International Journal of Polymer Science, 2011, 1-36.
[47] D. Dorniani, M. Z. B. Hussein, A. U. Kura, S. Fakurazi, A. H. Shaari, and Z. Ahmad. (2012). Preparation of Fe₃O₄ magnetic nanoparticles coated with gallic acid for drug delivery. International journal of nanomedicine, 7, 5745-5756.
[48] O. M. Medvedeva, V. S. Kurakina, S. G. Dmitrienko, T. I. Tikhomirova, and O. A. Shpigun. (2004). Separation and Determination of Phenolcarboxylic Acids by Capillary Zone Electrophoresis with Dynamic Preconcentration on Hypercrosslinked Polystyrene. Journal of Analytical Chemistry, 59 (7), 669-676.