Simultaneous Extraction? Spectrophotometric Determination of Trace Amounts of Barium and Potassium By 18-Crown-6 and Orange II

ABSTRACT

A simple and sensitive extraction-spectrophotometric method for the determination of barium and potassium is reported. The 18C6-Barium-Orange II (18C6-Ba-(OR II)₂) and 18C6-Potassium-Orange II (18C6-K-OR II) ternary complexes are quantitatively extracted into dichloromethane and their absorbances are measured at 483 nm. Linear calibration graphs were obtained over the barium concentration range of 0.1-5 μg ml⁻¹ and potassium concentration range of 1-8 μg ml⁻¹. The relative standard deviation for 2.0 μg ml⁻¹ barium and pottasium are, respectively, 4.16% and 3.60%. The interfering effect of a large number of diverse ions on the determination of barium and potassium was studied. The method was applied to a synthetic sample with natural matrix effects of tap water and the results showed high potential of the recommended method for the determination of Ba and K in water samples.

Keywords::

• Extraction
• Simultaneous determination
• Barium
• Potassium
• Orange II