production of selected secondary metabolites in transformed ...

IMPROVED FLUORIMETRIC DETERMINATION OF Al, Ga AND In
BY MICELLE ENHANCED 8-HYDROXYQUINOLINE -5-SULPHONIC
ACID COMPLEX
Šimon Vojta, 3. ročník DSP
Prof.RNDr.Lumír Sommer, DrSc.
Faculty of Chemistry, Brno University of Technology, Institute of Chemistry and Technology
of Environmental Protection, Purkyňova 118, 61200 Brno, e-mail: vojta@fch.vutbr.cz
INTRODUCTION
The enhancement (sensitization) of fluorescent reactions of metal ions with chelating dyes
by the presence of surfactants provides an inexpensive alternative to fluorimetric methods,
when determination of lower concentrations of elements is required.
The complexes formed in micellar media are often characterized by high molar
absorptivities, high stability over a wide pH range, and usually by large bathochromic shift
caused by addition of surfactants to the binary complex formed in water. Moreover, some
fluorescent binary chelates may dramatically increase their quantum yield in micellar media,
providing exceptionally sensitive fluorimetric methods.
The 8-hydroxyquinoline-5-sulphonic acid (QSA) should provide surfactant-sensitized
reactions with Al(III), Ga(III) and In(III), because it is strong acid readily yielding
a negatively charged group (sulphonate) to interact with the positive head of cationic
surfactants.
The importance of monitoring aluminium concentrations in the blood of patients
undergoing haemodialysis has been realised because of the suspicion that aluminium
intoxication is responsible for encephalopathy, oesteopathy and Alzheimer's disease.
In this work, the influence of various surfactants on the reaction of QSA with Al, Ga and
In is studied in details. Improved method of determination of Al, Ga, In by QSA in presence
of cationic surfactant Zephyramine is brought and optimized.
EXPERIMENTAL
REAGENTS
Aluminium standard, containing 1,000±0,002 g l -1 of Aluminium in 5% HCl, purchased
from Analytica, LTD. Prague
Gallium standard, containing 1,000±0,002 g l -1 of Gallium in 10% HCl, purchased from
Analytica, LTD. Prague
Indium standard, containing 1,000±0,002 g l -1 of Indium in 10% HCl, purchased from
Analytica, LTD. Prague
8-hydroxyquinoline-5-sulphonic acid – Sigma-Aldrich Co.
Benzyldimethyltetradecylammonium chloride (Zephyramine ® ) – Sigma-Aldrich Co.
1-ethoxykarbonylpentadecyltrimethylammonium bromide (Septonex ® )–Sigma-Aldrich Co.
Dodecylbenzyldimethylammonium bromide (Ajatin ® ) – Sigma-Aldrich Co.
Sborník soutěže Studentské tvůrčí činnosti Student 2006 a doktorské soutěže O cenu děkana 2005 a 2006
Sekce DSP 2006, strana 243