The usage of diglycylglycine (GGG) was proposed to improve the separation of the complexes of heavy metal ions with EDTA by capillary zone electrophoresis. The tripeptide can interact with the complexes in capillary and thereby acts as a complex selector.The influence of GGG on the electrophoretic behavior of ten metal complexes (Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Pb(II) and Bi(III)) was studied in an acidic media using a negative polarity voltage supply. Three modes were proposed for the implementation of the in-capillary complexation. An addition of the reagent to the phosphate buffer solution changes the migration order of the complexes thus enabling separation of Cr(III) from Zn(II) and Ni(II) and Co(II) from Cd(II) and Mn(II). It is possible to determine Fe(III) and Bi(III) complexes selectively in presence of the other heavy metal ions.An injection of separate zones of EDTA, metal ions and GGG doesn’t provide good separation. A consecutive injection of Me-EDTA and GGG zones leads to Cu(II) and Pb(II) separation. So, it is possible to determine four metal ions (Cu(II), Pb(II), Fe(III) and Bi(III)) simultaneously at 260 nm.Calibration graphs plotted in optimal conditions show linearity within the concentration range from 5·10-6 to 5·10‑3 mol/dm3. Limits of detection were calculated to be from 0.05 mg/dm3 for Pb(II) ions to 0.72 mg/dm3 for Bi(III). The proposed technique was applied for the determination of copper, lead, iron and bismuth in some natural and industrial samples.Keywords: capillary zone electrophoresis, copper, lead, iron, bismuth, EDTA, diglycylglycine. (Russian)DOI: http://dx.doi.org/10.15826/analitika.2014.18.4.013L.K. Neudachina, E.L. Lebedeva Federal State Autonomous Educational Institution of Higher Professional Education «Ural Federal University named after the first President of Russia B.N.Yeltsin» (UrFU), Ekaterinburg, Russian FederationReferences1. Vogt C., Klunder G.L. 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Analyst, 1998, vol. 123, no. 7, pp. 1497-1500. doi: 10.1039/A800892B.10. Neudachina L.K., Lakiza N.V., Lebedeva E.L. [Electrophoretic determination of copper(II) ions content in waters after complexation with ethylenediaminetetraacetic acid]. Zavodskaia laboratoriia [Industrial Laboratory], 2011, vol. 77, no. 1, pp. 813(in Russian).11. Lebedeva E.L., Neudachina L.K. [Simultaneous determination of heavy metal ions by capillary zone electrophoresis]. Materialy II Vserossiiskoi konferentsii «Analiticheskaia khromatografiia i kapilliarnyi elektroforez» [Proc. II All-Russ. Conf. “Analytical chromatography and capillary electrophoresis”].Krasnodar, 2013, p. 58 (in Russian).12. Conradi S., Vogt C., Wittrisch H., Knobloch G., Werner G. Capillary electrophoretic separation of metal ions using complex forming equilibria of different stabilities. J. Chrom. A, 1996, vol. 745, no. 1–2, pp. 103–109. doi:10.1016/0021-9673(96)00268-3.13. HaumannI., Bächmann K. On-column chelation of metal ions in capillary zone electrophoresis. J. Chrom. A, 1995, vol. 717, no. 1-2, pp. 385-391. doi:10.1021/ac00002a017.14. Tsioupi D.A., Stefan-vanStaden R.-I., Kapnissi-Christodoulou C.P. Chiral selectors in CE: Recent developments and applications // Electrophoresis. 2013, vol. 34, no. 1, pp. 178-204. doi: 10.1002/elps.201370013.15. Kartsova L.A., Komarova N.V. [Influence of α- and β-cyclodextrins on the separation of positional isomers of benzoic acid nitro, amino, chloro, and hydroxy derivatives by capillary electrophoresis]. Zhurnal analiticheskoi khimii [Journal of Analytical chemistry]. 2003, vol. 58, no. 10, pp. 1085-1092 (in Russian).16. Shpigun O.A., Anan'eva I.A., Budanova N.Iu., Shapovalova E.N. [Use of cyclodextrins for separation of enantiomers]. Uspekhi khimii [Russian Chemical Reviews], 2003, vol. 72, no. 12, pp. 1167-1189 (in Russian).17. Cucinotta V., Contino A., Giuffrida A., Maccarrone G., MessinaM. Application of charged single isomer derivatives of cyclodextrins in capillary electrophoresis for chiral analysis. J. Chrom. A, 2010, vol. 1217, no. 7, pp. 953-967. doi:10.1016/j.chroma.2009.11.094.18. Kuhn R., Stoecklin F., Erni F. Chiral separations by host-guest complexation with cyclodextrin and crown ether in capillary zone electrophoresis. Chromatographia, 1992, vol. 33, no. 1-2, pp. 32-36. doi:10.1007/BF02276847.19. Kuwahara Y., Nagata H., Nishi H., Tanaka Y., Kakehi K. Detection and separation of free amino acid enantiomers by capillary electrophoresis with a chiral crown ether and indirect photometric detection. Chromatographia, 2005, vol. 62, no. 9-10, pp. 505510. doi 10.1365/s10337-005-0658-9.20. Threeprom J., Som-aum W., Lin J. Capillary electrophoresis for the simultaneous determination of metals by using ethylenediamine tetraacetic acid as complexing agent and vancomycin as complex selector. Chinese J. Chem, 2006, vol. 24, no. 12, pp. 1747-1753. doi: 10.1002/cjoc.20069032721. Threeprom J., Som-Aum W., Lin J.-M. Determination of Pb(II), Cu(II) and Fe(III) with capillary electrophoresis using ethylenediaminetetraacetic acid as a complexing agent and vancomycin as a complex selector. Anal. Sci., 2006, vol. 22, no. 9, pp. 1179-1184. doi:10.2116/analsci.22.1179.22. Świątek M., Valensin D., Migliorini C., Gaggelli E., Valensin G., Jeżowska-Bojczuk M. Unusual binding ability of vancomycin towards Cu2+ ions. Dalton T., 2005. no. 23, pp. 3808-3813. doi: 10.1039/b508662k.23. Kucharczyk M., Brzezowska M., Maciag A., Lis T., Jezowska-Bojczuk M. Structural features of the Cu(2+)-vancomycin complex. J. Inorg. Biochem., 2008, vol. 102, no. 4, pp. 936-942. doi:10.1016/j.jinorgbio.2007.12.014.24. Carnegie P.R., Synge R.L.M. Filter-Paper ionophoresis of cupric complexes of neutral amino acids and oligopeptides. Biochem. J., 1961, vol. 78, no. 4, pp. 692-696.25. Talukdar H., Rudra S., Kundu K.K. Thermodynamics of transfer of glycine, diglycine, and triglycine from water to aqueous solutions of urea, glycerol, and sodium nitrate. Can. J. Chem., 1988, vol. 66, no. 3, pp. 461-468. doi:10.1139/v88-080.26. Stiasny E., Scotti H. Das Säure- und Alkali-Bindungsvermögen von Peptiden // Ber. Dtsch. Chem. Ges. 1930, vol. 63, no. 11, pp. 2977-2983. doi: 10.1002/cber.19300631110.27. Toroz D., van Mourik T. Structure of the gas-phase glycine tripeptide. Phys. Chem. Chem. Phys., 2010, vol. 12, no. 14, pp. 3463–3473. doi:10.1039/b921897a.28. Dobbie H., Kermack W.O. Complex-formation between polypeptides and metals. 3. The reaction between cupric ions and diglycylglycine. Biochem. J., 1955, vol. 59, no. 2, pp. 257-264.29. Murphy C.B., Martell A.E. Metal chelates of glycine and glycine peptides. J. Biol. Chem., 1957, vol. 226, no. 1, pp. 037-050.30. Várnagy K., Szabó J., Sóvágó I., Malandrinos G., Hadjiliadis N., Sanna D., Micera G. Equilibrium and structural studies on copper(II) complexes of tetra-, penta- and hexa-peptides containing histidyl residues at the C-termini. J. Chem. Soc. Dalton., 2000. no. 4, pp. 467-472. doi: 10.1039/A907342F.31. The IUPAC Stability Constants Database, SC-Database and Mini-SCDatabase. Available at: http://www.acadsoft.co.uk/scdbase/scdbase.htm (accessed 17 June 2014).32. HySS2009. Hyperquad Simulation and Speciation. Available at: http://www.hyperquad.co.uk/hyss.htm (accessed 17 June 2014).33. Neudachina L.K., Lebedeva E.L., Kuznetsov A.O. [Application of capillary zone electrophoresis to the determination of copper in tea]. Khimiia rastitel'nogo syr'ia [Chemistry of plant raw material]. 2011, no 4, pp. 161-167 (in Russian)., На основании анализа литературных данных выбрано соединение (диглицилглицин – ГГГ), способное повысить селективность разделения этилендиаминтетраацетатных комплексов ионов тяжелых металлов методом капиллярного зонного электрофореза (КЗЭ). Показано, что трипептид глицина, взаимодействуя с комплексами Ме-ЭДТА в капилляре, может выступать в роли комплекс-селектора.Влияние ГГГ на электрофоретическое разделение комплексов десяти металлов (Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Pb(II) и Bi(III)) исследовано в кислой среде, при отрицательной полярности источника напряжения, с использованием трех вариантов осуществления внутрикапиллярного комплексообразования. Добавление реагента в состав фосфатного ведущего электролита приводит к изменению собственных подвижностей комплексов Ме‑ЭДТА и позволяет отделить комплексы Cr(III) от Zn(II), а Ni(II) и Co(II) – от Cd(II) и Mn(II). Возможно селективное определение комплексов Fe(III) и Bi(III) в присутствии других переходных металлов.Разделение ионов тяжелых металлов при вводе отдельных зон комплексообразующих реагентов и пробы оказывается недостаточно селективным. При вводе отдельных зон ГГГ и комплексов Ме-ЭДТА достигается разделение комплексов Cu(II) и Pb(II). Таким образом, становится возможным одновременное определение ионов четырех металлов (Cu(II), Pb(II), Fe(III) и Bi(III)) при 260 нм.В оптимальных условиях анализа градуировочные графики линейны в диапазоне 5·10-6 ÷ 5·10‑3 моль/дм3, величины пределов обнаружения составляют от 0.05 мг/дм3 для Pb(II) до 0.72 мг/дм3 для Bi(III). Разработанный способ применен для анализа образцов отходов металлургического производства, печного шлака, сложного оксида, а также зеленого чая. Результаты анализа хорошо соотносятся с результатами, полученными методами атомно-абсорбционной и атомно-эмиссионной спектроскопии.Ключевые слова: капиллярный зонный электрофорез, медь, свинец, железо, висмут, ЭДТА, диглицилглицинDOI: http://dx.doi.org/10.15826/analitika.2014.18.4.013 ЛИТЕРАТУРА1. Vogt C., Klunder G.L. 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