A rapid and simple preconcentration method by selective adsorption using activated carbon as an adsorbent and potassium O-ethyldithiocarbonate (potassium xanthogenate) is described for the determination of trace amounts of thallium in sediments by graphite furnace AAS. The procedure is as follows: to 100 cm3 of sample solution containing less than 0.5 μg of thallium, 60 mg of potassium xanthogenate and 60 mg of activated carbon were added. The pH was then adjusted to 8.0∼10.0 using dilute ammonia water. The mixture was allowed to stand for approximately 20 min, then mixed for 20 s in an ultrasonic agitator and then filtered. The activated carbon which adsorbed the thallium complex was separated from the matrixes. The activated carbon on the filter paper was dispersed in 5 cm3 of water by mixing using an ultrasonic agitator. After shaking, 10 μ l of the suspension was directly injected into the graphite furnace. Both palladium and ascorbic acid were used as matrix modifiers for thallium. The proposed method was used to determine the amount of several environmental reference standard materials, river and marine bottom sediments. The results for standard materials were in good agreement with the certified or reference values. This simple method is suitable for the determination of trace amounts of thallium in the sample containing large amounts of Fe, Al, Ca, Ti and the other elements.
- adsorption of thallium-ethylxanthate complex on activated carbon
- determination of thallium in sediments using graphite furnace AAS
- potassium ethylxanthate
ASJC Scopus subject areas
- Analytical Chemistry