Tellurium determination by flame atomic absorption spectrometry using a slotted quartz tube atom trap and metal coatings

Osmanbaşoğlu, Mahmut
Flame Atomic Absorption Spectroscopy (FAAS) has lover sensitivity than similar analytical methods, however it has an important place for analysis due to its easy application and economic practicability especially in metal determinations. In order to increase the sensitivity of FAAS from mg/L level to ng/L level, various atom trap systems have been used. One of these atom traps, Slotted Quartz Tube (SQT), which is easy, economical and useful for volatile element determination, is used in this study as a sensitive analytical method for determination of tellurium. In the study, determination of Te by SQT is handled in three different modules. First, only with SQT itself, longer residence time for Te atoms in the measurement zone is provided and consequently 3.2 fold sensitivity enhancement is obtained both for Te (VI) and Te (IV). In the second module, SQT is used for concentration of tellurium species in a lean flame by sending the analyte into SQT for a definite time and trapping them on the inner surface of the SQT. After trapping the analyte, in order to determine the Te concentration, a small volume (10-50 µL) of organic solvent such as methyl ethyl ketone (MEK) is introduced to the flame for revolatilization and a rapid atomization of Te on the surface is provided. In this trapping method, for 5 minutes collection with a 6 mL/min suction rate, 143 fold enhancement for Te (VI) and 142 fold enhancement for Te (IV) were obtained. In the third module, different from the second one, the inner surface of the SQT is coated with different metals for increasing the amount of Te trapped on the surface and the best enhancement for tellurium is obtained with Tantalum-coated SQT with 252 fold enhancement for Te (VI) and 246 fold enhancements for Te (IV). All improvements are calculated according to the signals obtained in FAAS method. Separate calibration plots were used for Te (IV) and Te (VI).


Lead determination by flame atomic absorption spectrometry using a slotted quartz tube atom trap and metal coatings
Demirtaş, İlknur; Ataman, Osman Yavuz; Department of Chemistry (2009)
Flame Atomic Absorption Spectrometry (FAAS) still keeps its importance despite the relatively low sensitivity; because it is a simple and economical technique for determination of metals. In recent years atom traps have been developed to increase the sensitivity of FAAS. Although the detection limit of FAAS is only at the level of mg/L, with the use of atom traps it can reach to ng/mL. Slotted quartz tube (SQT) is one of these atom traps, it is applied for determination of volatile elements; it is economica...
On-line preconcentration, speciation and determination of chromium by flame atomic absorption spectrometry(faas) and chemiluminescence
Sürdem, Sedat; Volkan, Mürvet; Department of Chemistry (2004)
Toxicological studies have shown that the degree of toxicity of some elements depends on the chemical form in which the element is present. Chromium (III) is considered as an essential micronutrient for human whereas chromium (VI) is a potentially carcinogenic agent. So the speciation of inorganic chromium in environmental samples is required for accurate assessment of pollution levels. The chromium content in natural water is usually very low, and a preconcentration is often necessary prior to the determin...
Spectroelectrochemical and Photovoltaic Characterization of a Solution-Processable n-and-p Type Dopable Pyrrole-Bearing Conjugated Polymer
Baran, Derya; Balan, Abidin; Esteban, Beatriz-Meana; Neugebauer, Helmut; Sariciftci, Niyazi Serdar; Toppare, Levent Kamil (Wiley, 2010-12-15)
D-A-D-type polymers are of high interest in the field of photovoltaics and electrochromism. In this study we report the synthesis and electrochemical properties of PPyBT along with its photophysical properties and photovoltaic performance. PPyBT is soluble in common organic solvents and both n- and p-type dopable, which is a desired property for conjugated polymers. During electrochemistry studies, the onset potentials of the polymer were determined as +0.2V for oxidation and -1.4V for reduction. Using thes...
Rational design of ratiometric chemosensor via modulation of energy donor efficiency
Guliyev, Ruslan; Akkaya, Engin Umut; Department of Chemistry (2008)
Rational design of fluorescent chemosensors is an active area of supramolecular chemistry, photochemistry and photophysics. Ratiometric chemosensors are even more important, as they have an internal system for selfcalibration. In order to develop a new methodology for a ratiometric chemosensor design, we proposed coupling of energy transfer phenomenon to ion sensing. In this study, we targeted energy transfer cassette type chemosensors, where the efficiency of transfer is modulated on the donor side, by met...
Asymmetric synthesis of chiral camphor fused pyridine type novel organocatalysts
Küçükdişli, Murat; Tanyeli, Cihangir; Department of Chemistry (2009)
Chiral pyridines as organocatalysts have been used in asymmetric organic synthesis in recent years. The asymmetric synthesis of camphor fused pyridine type novel organocatalysts were perfomed starting from cheap and easily available natural (+)-camphor. Using camphor fused pyridine skeleton, six organocatalysts 29, 32, 33, 38, 40, and 41were successfully synthesized. The first four nucleophilic and Lewis base catalysts 29, 32, and 33 are different P-oxides and P,N-dioxides which were tested in allylation of...
Citation Formats
M. Osmanbaşoğlu, “Tellurium determination by flame atomic absorption spectrometry using a slotted quartz tube atom trap and metal coatings,” M.S. - Master of Science, Middle East Technical University, 2011.