| Autor: |
Balcerzak M; Department of Analytical Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland. mbal@ch.pw.edu.pl, Kopacz M, Kosiorek A, Swiecicka E, Kus S |
| Jazyk: |
angličtina |
| Zdroj: |
Analytical sciences : the international journal of the Japan Society for Analytical Chemistry [Anal Sci] 2004 Sep; Vol. 20 (9), pp. 1333-7. |
| DOI: |
10.2116/analsci.20.1333 |
| Abstrakt: |
Results of some studies on the interaction of noble metals with quercetin (Q) and quercetin-5'-sulfonic acid (QSA), the compounds of flavonoid group, are presented. The reactions of chloride complexes of the metals: RuOHCl5(2-), PdCl4(2-), OsCl6(2-), PtCl6(2-) and AuCl4- with both reagents were examined. The redox reactions of ruthenium and gold with Q and QSA have been identified. The reaction of the metals with both reagents results in the formation of the oxidized form of Q that exhibits maximum absorbance at 291 nm. Ruthenium and gold react with the examined reagents under similar conditions: 0.04 M HCl and 1 x 10(-4) M Q (or QSA). The CH3OH + H2O (1:1) (Q) and pure aqueous (QSA) media can be used. The reaction of gold with Q is slow at room temperature. It can be accelerated by heating the solution being examined. The reaction proceeds significantly faster when the water-soluble sulfonic derivative of quercetin, quercetin-5'-sulfonic acid, is used as a reagent. The new species formed can make the basis of spectrophotometric methods for the determination of ruthenium and gold. The molar absorptivities at 291 nm are equal to 5.0 x 10(3) and 2.2 x 10(4) L mol(-1) cm(-1) for Ru and Au, respectively, independently of the reagent used. Some methods for the determination of the content of gold (0.04%) in a cosmetic cream were developed. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
|
Full text from SpringerLink