Tez özetleri Astronomi ve Uzay Bilimleri Anabilim Dalı

Investigation of Fibre Optic Lead Sensor

Lead is a toxic metal that can be accumulated in the organism over a lifetime. Lead is present in food, beverages, dye and pigment particles, natural water and crystalline glass objects. Especially acidic non- alcoholic beverages may play an important role on the uptake by the organism. The basic reasons of lead accumulation in humans are tetraetyl lead – added gasoline and lead arsenate compounds in commercial pesticide formulations.

Lead poisoning (plumbism) influences with priority the concerned industrial sector workers and to a lesser extent urban populations. As  a result of unplanned urbanization and industrialization, lead accumulation levels in humans may cause development failure not only in babies and children but also in eldery people. Especially the transport vehicles fueled with lead –added gasoline may cause chronic Pb poisoning under heavy traffic conditions. Thus the determination of lead in environmental samples and diverse applications in very important for human healt.

Various spectrometric techniques ( ICP-MS, GFAAS, ICP-AES and FAAS etc.) exist in literature for trace lead determination. All these literature methods are relatively expensive and enable analysis in the laboratory with trained personnel. In situ or field analytical requirements and easy to use optical sensors may meet such requirements. In recent years, many studies have appeared for the use of optical sensors in Pb determination.

A fibre optic sensor based on the use of 2,7-bis(2-arsenophenylazo) 1,8-dihydroxynaphthalene-3,6-disulphonic acid, commonly called Arsenazo-III (ASA III) immobilized onto XAD-16, has been developed for the rapid reflectance spectrometric determination of lead (II). The measurements were carried out at a wavelength of 664.64 nm since it yielded the largest divergence different in reflectance spectra before and after reaction with the analyte element. The sensor was found to have an optimum response at pH=5.0. The sensor response from different probes (n = 5) gave an R.S.D. of 0.23 % at 2.07 ppm Pb(II). The dynamic working response of Pb(II) was found within the concentration range of 0.06–20.7 ppm, with a LOD of 0.01 ppm. The tolerance limits of coexisting ions were also investigated. The sensor can easily be regenerated by immersion in 0.1 M HNO3. The proposed sensor was applied to the determination of Pb(II) in commercial gasoline and glass samples with satisfactory results.

ÇENGEL Tayfun
Danışman : Prof. Dr. İzzet TOR

Anabilim Dalı : Kimya

Programı : Analitik Kimya

Mezuniyet Yılı : 2009

Tez Savunma Jürisi : Prof. Dr. İzzet TOR

Prof. Dr. Hayati FİLİK

Prof. Dr. Reşat APAK

Prof. Dr. Esma TÜTEM

Prof. Dr. İsmail BOZ.