Methylene blue has been proposed as a new analytical reagent for the catalytic spectrophotometric determination of thallium (I). It reacts with ascorbic acid in acidic medium to form a colorless product. Thallium (I) increases the rate of reaction and it can be determined base on its catalytic effect on the reaction. The reagents and manifold variables influences on the sensitivity were investigated and the optimum conditions were established. The reaction has been followed spectrophotometrically by measuring the decrease in the absorbance of methylene blue at 664 nm. A fixed time method of 180.0 s from initiation of the reaction was used. Under optimum conditions, the proposed method allows the determination of thallium concentrations in the range 3.0-200mg/mL with a detection limit of 0.09mg/mL. This method is free from of most interference. The results of the proposed method for water samples were comparable with atomic absorption spectroscopy and were found to be in good agreement.

The value of dobutamine infusion during thallium 201 imaging at rest was assessed in 37 patients with chest pain and suspected coronary artery disease. Dobutamine was infused in 3- minute stages at incremental doses from 5-40 mg/kg/min as tolerated. Coronary angiograms were obtained 2 days later. 23 patients had significant coronary artery stenosis and the remaining 14 had normal coronary arteries. Positive thallium 201 defects were present 10 patients with CAD (sensitivity 83%) and in 3 patients without CAD (specificity 78%). The values are significantly better than the usual exercise test. Dobutamine was well tolerated by patients without significant arrhythmias and no major limiting symptoms except chest pain and palpitation. We conclude that dobutamine infusion with thallium 201 imaging is a well tolerated, accurate and sensitive method for diagnosing coronary artery disease in patients who can not exercise or are unable to use vasodilator drugs for the for detection of coronary artery disease.

Thallium-203 is the main material for 201TICl3 radiopharmaceutical. It is very important to recover the remaining enriched Thallium-203 in every stage of the process to be reused in the production loop. In this research, the recuperation of Thallium-203 was studied with Dowex 50WX8 ion exchange resin and Thallium-201 as a tracer. The results based on filling of (18x1.5) cm columns with this resin showed that the best flow rate of eluent is 2 mL/min. Also the most suitable volumes are {200 mL (RNO3 0.05 M), 400 mL (solution of Thallium-203), 100 mL (H2O), 500 mL (Citric acid), 100 mL (H2O), 100 mL (EDTA 0.5 M &pH~12.5), 60 mL (H2O), respectively.

A fast and centrifuge-less method called dispersive–, restoration suspended droplet microextraction was developed for selective determination of trace amounts of Tl(III) by flame atomic absorption spectroscopy. In this method, 8-hydroxy quinoline was used as a complexing agent and toluene was used as an extracting solvent. The effective parameters for determination of Tl(III), such as type of extraction solvent, dispersive time, resting time, magnetic stirrer speed and time, and pH were optimized. Under the optimum conditions, the calibration curve was found to be linear in the range of 8. 0-1000 µ, g l = 0. 997. The percent of relative standard deviation (n = 15), limit of detection, and enrichment factor were 1. 4%, 3. 1 µ, g l-1 2 with R and 33, respectively. The method was successfully applied for determination of total thallium in real samples including water, nail and hair samples. The good recoveries in the range of 96-103% for real samples confirmed the accuracy and applicability of the present method.

In the presence of low energy gamma emitter radioisotopes of thallium-201 (201Tl) or technetium-99m (99mTc), H2O2 was generated via radiolysis of water. The produced H2O2 was amperometrically determined using an anthraquinone 2-carboxylic acid modified horseradish peroxidase on glassy carbon electrode. In the presence of each radioisotope, the cathodic current produced due to the amperometric detection of H2O2, was designated as biosensor response. At the applied potential of -550 mV (vs. Ag/AgCl), the biosensor showed the sensitivities of 1.937 and 2.278 nA h mGy-1 towards H2O2 produced by 201Tl and 99mTc respectively. Finally, the calibration curves for dose rate determination of 201Tl and 99mTc have been presented and the correlations between biosensor response to H2O2 and the gamma emitter dose rates for 201Tl and 99mTc are established.

In this research we have determined neutrons spectrum and the intensity that produced from thallium target bombardment. We have applied SRIM and ALICE computer codes to thallium target and its copper substrate for 145 mA of 28.5 MeV incident proton beam from cyclotron Cyclone 30. Because of the energy degradation of protons while passing through the thallium target and its copper substrate, the average energy of protons in different depths has been calculated by using SRIM computer code. Then, by applying ALICE computer code for each sub-layer, the neutron production cross sections and their energy spectrum have been calculated to determine the total neutron intensity and spectrum. Using the calculated neutron intensity of 1.22x1013 n/s as the source, the equivalent dose rate at the distance 6 meters from the target has been calculated by MCNP computer code and the result has been compared with the measured value. The 201Pb activity has also been calculated as 13.5 Curies. The measured 201Pb activity by Curie meter CAPINTEC CRC-712 is 13.1 Ci which is in reasonable agreement with the calculated value, bearing in mind the uncertainties in the proposed models and the measurements.

In this study, magnetic multi walled carbon nanotubes were prepared by Dicyclohexyl-18-crown-6 ligand for preconcentration of trace amount of Thallium ions. The optimum pH for maximum absorption of Thallium was between 6-7. Maximum absorption capacity was 39.5 mg of Thallium per gram of adsorbent and the breakthrough volume is 400 mL. Detection limits was 4.67 ng L-1 and the relative standard deviation was found to be 2.9%. Linearity was within the range of 0.024-0.668 mg L-1 with good correlation coefficient (0.998). In this study FT-IR analysis technique and SEM image was performed on nanoparticles. This method is simple, selective and sensitive, and can be applied to the determination of Thallium in various samples.