Preparation of a novel iron(iii) selective membrane electrode based on crown ether and its application

vPREPARATION OF A NOVEL IRON (III) SELECTIVE MEMBRANEELECTRODE BASED ON CROWN ETHER AND ITS APPLICATION(M.Sc. Thesis)Demet UZUNGAZİ UNIVERSITYINSTITUTE OF SCIENCE AND TECHNOLOGYOctober 2006ABSTRACTA new membrane electrode selective to iron(III) ion (in FeCl4- structure) hasbeen developed based on crown ether. The electrode consisted of trans-dinitro-dibenzo-18-6 crown ether as a neutral carrier, 2-nitrophenyl penthyl ether asplasticizer and tetrabuthylammonium tetraphenylborate as conductivityincreaser. An analytically useful potential change occurs in the 1x10-6-1x10-1 Mconcentration range. The slope of linear portion was 50,6±1,1 mV in 1x10-5-1x10-1 M concentration range of iron(III). The measurements were made atconstant ionic strength (0,1 M NaNO3, 0,1 M HCl medium) and at roomtemperature. In the presence of 1x10-3 M iron(III) no interference was observedfor NO 3 , ClO − , SO 2 − , K+, Na+, Ag+, Cu2+, Co2+, Pb2+, Mn2+, Cr3+, Ti4+, Ni2+−4 4ions. This electrode has been used for the direct determination of iron(III) inblood and in grape molasses which is traditional syrup made of grapes. Theamount of iron(III) found was 33,2±0,8 µg/100 mL in blood and 51,4±0,8 µg/g insyrup. The lifetime of the electrode was approximately 2 months when used 5times a day and the response time was about 30-60 seconds.Science Code : 201.1.004Key Words : Ion selective electrode; Iron (III); crown etherPage Numbers : 80Adviser : Prof. Dr. Güler SOMER