Abstract
A new sensitive and selective derivative spectrophotometric procedure is developed for trace‐level determination of Tl3+ in the range of 6.80 × 10−2 to 3.80 µg mL−1; molar absorption coefficient and detection limit of a 1:1 complex with 2‐(5‐bromo‐2‐pyridylazo)‐5‐diethylaminophenol in the presence of cetylpyridinium chloride are 5.25 × 104 L mol−1 cm−1 and 4.20 × 10−2 ng mL−1, respectively. The developed method, by using the measurement of the derivative amplitude of the analyte (Tl3+) at the zero crossover point of the interfering metal ion (Ga3+), is applied for the determination of Tl3+ in the presence of Ga3+, and vice versa for Ga3+ ions. The determination range of Tl3+ and Ga3+ in the presence of each other is 0.10–2.46 µg mL−1 and 0.04–1.05 µg mL−1, respectively; the relative standard deviation for sample containing 1.23 µg mL−1 Tl3+ and 0.42 µg mL−1 Ga3+ is 1.43 and 1.65%, respectively. The proposed procedure is successfully applied for simultaneous determination of the two metal ions in the environmental samples, standard reference materials, and synthetic binary mixtures.
Acknowledgments
The authors gratefully acknowledge the financial assistance provided by UGC (JRF) to SR and to Prof. H. B. Singh for suggestions.