Determination of quercetin in pharmaceutical formulations via its reaction with potassium-titanyloxalate: Determination of the stability constants of the quercetin-titanyloxalato complex
Određivanje kvercetina u farmaceutskim preparatima preko reakcije sa kalijum-titaniloksalatom - određivanje konstanti stabilnosti kvercetin-titaniloksalatnog kompleksa
dc.creator | Kuntić, Vesna | |
dc.creator | Pejić, Nataša | |
dc.creator | Mićić, Svetlana | |
dc.creator | Vukojević, Vladana | |
dc.creator | Vujić, Zorica | |
dc.creator | Malešev, Dušan | |
dc.date.accessioned | 2019-09-02T11:02:39Z | |
dc.date.available | 2019-09-02T11:02:39Z | |
dc.date.issued | 2005 | |
dc.identifier.issn | 0352-5139 | |
dc.identifier.uri | https://farfar.pharmacy.bg.ac.rs/handle/123456789/657 | |
dc.description.abstract | Asimple, rapid and accurate procedure for the quantitative determination of quercetin in its pure form and in formulations has been developed. The method is based on the spectrophotometric determination of a complex formed between quercetin and potassium titanyloxalate in 50 % ethanolic solutions. To characterize the quercetin titanyloxalato complex, the stability constants of the complex were determinated potentiometrically and spectrophotometrically at different temperatures (T = 26.0oC, 34oC and 39.0oC), as well as at different ionic strengths (I = 5.0x10-4 mol dm-3, 3.0x10-2 mol dm-3 and 6.0x10-2 mol dm-3) and the thermodynamic parameters were calculated. As quercetin is usually conjugated to vitamin C in pharmaceutical formulations, two procedures for the quantitative determination of quercetin by this complexing reaction were tested - both in the absence and presence of ascorbic acid. In both procedures, the Beer law was obeyed over the same concentration range of quercetin, i.e., 0.85 μg mL-1 - 16.9 μg mL-1. In the first procedure in the absence of ascorbic acid the molar absorptivity coefficient of the quercetin-titanyloxalate complex is a=2.49 x 104 mol-1 dm3 cm-1, Sandells sensitivity of the method is S = 1.35 x 10-2 μg cm-2 and the detection limit is d = 0.67 μg mL-1. Whereas, in the presence of ascorbic acid (second procedure) a = 3.04 x 104 mol-1 dm3 cm-1, S = 1.11 x 10-2 μg mL-1. The proposed method was verified for the determination of quercetin in pharmaceutical dosage forms. | en |
dc.description.abstract | Predložen je brz, jednostavan i tačan metod za određivanje kvercetina u farmaceutskim sirovinama i doziranim oblicima.Metod je baziran na spektrofotometrijskom određivanju kompleksa formiranog između kvercetina i kalijum-titaniloksalata u 50 % etanolu. Određene su konstante stabilnosti kvercetin titaniloksalatnog kompleksa potenciometrijski i spektrofotometrijski na različitim temperaturama (T = 26.0oC, 34oC and 39.0oC) i jonskim jačinama (I = 5.0x10-4 mol dm-3, 3.0x10-2 mol dm-3 and 6.0x10-2 mol dm-3) i izračunati su termodinamički parametri. Kako se kvercetin uobičajeno nalazi zajedno sa vitaminom C u doziranim oblicima, predložene su dve procedure za određivanje kvercetina: bez i u prisustvu askorbinske kiseline.U obe predložene procedure, Beer-ov zakon važi u oblasti 00.85 μg mL-1 - 16.9 μg mL-1 kvercetina. Prema prvoj proceduri, molarni apsorpcioni koeficijent kvercetin–titaniloksalatnog kompleksa je a=2.49 x 104 mol-1 dm3 cm-1, Sandelova osetljivost metode je S = 1.35 x 10-2 μg cm-2, a limit detekcije je d = 0.67 μg mL-1. Prema drugoj proceduri, a = 3.04 x 104 mol-1 dm3 cm-1, S = 1.11 x 10-2 μg mL-1. Predloženi metod je primenjen za određivanje kvercetina u doziranim oblicima. | sr |
dc.publisher | Srpsko hemijsko društvo, Beograd | |
dc.relation | Ministarstvo nauke RS, br. 1458 | |
dc.rights | openAccess | |
dc.rights.uri | https://creativecommons.org/licenses/by-nc-nd/4.0/ | |
dc.source | Journal of the Serbian Chemical Society | |
dc.subject | quercetin | en |
dc.subject | potassium titanyloxalate | en |
dc.subject | spectrophotometric determination | en |
dc.subject | stability constants | en |
dc.subject | dosage form | en |
dc.title | Determination of quercetin in pharmaceutical formulations via its reaction with potassium-titanyloxalate: Determination of the stability constants of the quercetin-titanyloxalato complex | en |
dc.title | Određivanje kvercetina u farmaceutskim preparatima preko reakcije sa kalijum-titaniloksalatom - određivanje konstanti stabilnosti kvercetin-titaniloksalatnog kompleksa | sr |
dc.type | article | |
dc.rights.license | BY-NC-ND | |
dcterms.abstract | Вукојевић, Владана; Мићић, Светлана; Кунтић, Весна; Малешев, Душан; Вујић, Зорица; Пејић, Наташа; Одређивање кверцетина у фармацеутским препаратима преко реакције са калијум-титанилоксалатом - одређивање константи стабилности кверцетин-титанилоксалатног комплекса; Одређивање кверцетина у фармацеутским препаратима преко реакције са калијум-титанилоксалатом - одређивање константи стабилности кверцетин-титанилоксалатног комплекса; | |
dc.citation.volume | 70 | |
dc.citation.issue | 5 | |
dc.citation.spage | 753 | |
dc.citation.epage | 763 | |
dc.citation.other | 70(5): 753-763 | |
dc.citation.rank | M23 | |
dc.identifier.wos | 000230375900010 | |
dc.identifier.doi | 10.2298/JSC0505753K | |
dc.identifier.scopus | 2-s2.0-31544478536 | |
dc.identifier.fulltext | https://farfar.pharmacy.bg.ac.rs//bitstream/id/2152/655.pdf | |
dc.type.version | publishedVersion |