Study of the sorption properties of solvents in thinlayer and column chromatography

Much attention is paid to the consideration of the causes of transformer oil aging under the influence of technogenic and natural factors. The paper insulation destruction mechanism is considered, as a result of which furan compounds are formed that enter the transformer oil and worsen its dielectric characteristics. The characteristics of the domestic transformer oil grade GK-1 obtained using the technology of hydrocracking in a hydrogen medium are given. Furan compounds are formed in used transformer oil, which are monitored using chromatographic analysis methods according to standard procedures. The group composition of transformer oil was determined using thin layer chromatography. As a solvent used n. Hexane. To extract furan compounds from transformer oil, various organic solvents are used, the physicochemical properties of which are given in this work. It was found that the retention time of the studied sorbates corresponds to an increase in their boiling points for ethyl acetate, methyl ethyl ketone and dodecane. In the case of isopropanol, which has a close boiling point with ethyl acetate and methyl ethyl ketone, a significant increase in retention time is observed, which is associated with the formation of an intermolecular hydrogen bond. The dependence of the spot diameter of furan substances on their concentration was established under conditions of thin-layer chromatography on Sorbfil plastics. Moreover, the most effective separation is characteristic of furfural. In this case, the chromatographic spots are small in size with good fidelity. The ascending mode of column liquid chromatography was used to determine the dependence of the retention time of standard sorbates on the length of the Silyochrome S-80 sorption layer, which is parabolic. It was found that the highest retention times are characteristic of ethoxyethanol and isopropanol, which is consistent with the known theoretical principles of liquid chromatography. Histograms of the effect of the retention time of standard sorbates on their nature and boiling point, where isopropanol and 2-ethoxyethanol are extreme, are presented. In this case, isopropanol having a lower boiling point than 2-Ethoxyethanol is retained on the sorbent more strongly, which is associated with the formation of intermolecular hydrogen bonds with surface silanol groups of the sorbent.

1. Kozlov VK, Saditov AKh. Stepen' polimerizatsii bumazhnoi izolyatsii silovykh transformatorov. Izvestiya vysshikh uchebnykh zavedenii. Problemy energetiki. 2018;20(9-10):34-38.

2. Novikov VF. Diagnostika maslonapolnennogo elektrooborudovaniya khromatograficheskimi metodami. Novye tekhnologii, materiala i oborudovaniya. ed. Abdullazyanov E.Yu., Shamsutdinov E.V. Kazan State Power Engineering University, Russia. 2018;3:138-160.

3. Kozlov V.K., Sabitov A.Kh., Nizamutdinov B.R. Issledovanie protsessa stareniya bumazhnomaslyanoi izolyatsii v vidimom diapazone. Izvestiya vysshikh uchebnykh zavedenii. Problemy energetiki. 2015;3-4:81-85.

4. Kurakina OE, Kozlov V.K, Turanova O.A, et al. Research of the Changes in the Structural Group Composition of Transformer Oil During Operation. Problemele energeticii regionale. 2018;2(37):39-45.

5. Novikov VF, Kartashova AA, Taneeva A.V. Instrumental'nye metody analiza. Ch.3. Gazokhromatograficheskii kontrol' proizvodstvennykh protsessov v energetike: Monografiya. Kazan State Power Engineering University 2018. 328 p.

6. Mackenzie E, Crossey J, De Pablo A, et al. On-line monitoring and diagnostics for power transformer. IEEE International symposium on electrical insulation conference. 2010. pp. 1-5.

7. Ding H, Heywood R, Lapworth G, et al. Learning from success and failure in transformer fault gas analysis and interpretation. International conference on reliability of transmission and distribution networks. 2011. pp. 1-6.

8. Krause Ch, Piovan U, Tschudi D. Building reliable AC and DC UHV power transformers dielectric design principles, suitable pressboard insulation and issues related to HVDC testing. Proceeding of international conference on UHV transmission. Beiying, China. 2009. pp. 28-34.

9. Baird P, Herman H, Stevens G. Spectroscopic measurement and analysis of water and oil in transformer insulating paper. IEEE Transactions on Dielectric and Electrical Insulation. 2006;13:293-308.

10. Zukowski P, Koltunowicz T, Kierczynski K, et al. An analysis of AC conductivity in moist oilimpregnated insulation pressboard. IEEE Transactions on Dielectrics and Electrical Insulation. 2015;22(4):2156-2164.

11. Sarathi R, Yadav KS, Swarna M. Understanding the surface discharge characteristics of thermally aged copper sulphide diffused oil impregnated pressboard material. IEEE Transactions on Dielectrics and Electrical Insulation. 2015;22(5):2513-2521.

12. Bo Qi, Xiaolin Zhao, Chengrong Li, Hao Wu. Transient electric field characteristics in oilpressboard composite insulation under voltage polarity reversal. IEEE Transactions on Dielectrics and Electrical Insulation. 2015;22(4):2148-2155.

13. Kartashova AA, Novikov VF. Opredelenie furanovykh soedinenii v transformatornom masle gazokhromatograficheskim metodom s ispol'zovaniem novykh sorbentov. Izvestiya vysshikh uchebnykh zavedenii. Problemy energetiki. 2016;1-2:47-52.

14. RD 34.43.206-94. Metodika kolichestvennogo khimicheskogo analiza. Opredelenie soderzhaniya proizvodnykh furana v elektroizolyatsionnykh maslakh metodom zhidkostnoi khromatografii. M.: ORGRES. 1995. 12 p.

15. RD 34.43.208-95. Metodika kolichestvennogo khimicheskogo analiza. Opredelenie soderzhaniya prisadok v energeticheskikh maslakh metodom vysokoeffektivnoi zhidkostnoi khromatografii. M.: ORGES. 1995. 12 p.

16. L'vov Yu.N, Pisareva NA, Sapozhnikov YuM. Primenenie tonkosloinoi khromotografii pri opredelenii mikrokolichestv furanovykh proizvodnykh v izolyatsionnom masle elektrooborudovaniya. Elektricheskie stantsii. 1993;8:48-51.

17. Kartashova AA, Novikov VF. Tonkosloinaya khromatografiya kak metod kontrolya furanovykh soedinenii v transformatornom masle. Izvestiya vysshikh uchebnykh zavedenii. Problemy energetiki. 2016;1- 2:138-145.

18. Taneeva AV, Ziatdinova RV, Stoikov I, et al. Vliyanie prirody rastvoritelei na sorbtsionnye svoistva tonkosloinykh plastinok «Sorbfil», modifi- tsirovannykh nanochastitsami tiakaliks[4]aren/SiO2. Sorbtsionnye i khromatograficheskie protsessy. 2018. T. 18. № 6. S. 865-871.