RAPID AND SENSITIVE DETERMINATION OF AMILORIDE BY CATION EXCHANGE PRECONCENTRATION AND DIRECT SOLID-PHASE UV DETECTION

ABSTRACT

A rapid, sensitive and simple spectrophotometric method for the determination of amiloride in pharmaceutical preparation and urine is described in this paper. The method is based on the sorption of amiloride on a cation-exchange resin (Sephadex SP C-25) at pH 4.0 and the direct measurement of its intrinsic UV absorbance in the solid phase at 362 nm (the maximum absorption wavelength) and 412 nm (wavelength at which only the solid support absorbs light). The calibration graphs were linear from 0.8 to 7, 0.08 to 0.7 and 0.02 to 0.15 µg mL⁻¹ with detection limits of 0.2, 0.02 and 0.006 µg mL⁻¹ for 10, 100 and 500 mL sample volumes, respectively. The relative standard deviations for ten independent determinations were better than 3.46%. The one step method was satisfactorily applied to the rapid determination of amiloride in pharmaceutical preparations and urine without any pre-treatment of the samples.

Keywords:

• Amiloride determination
• Solid phase spectrophotometry
• Pharmaceuticals and urine

ACKNOWLEDGMENTS

The authors are grateful to the Ministerio de Educación, Cultura y deportes de Espana, Dirección de Enseñanza Superior e Investigación Científica (Project No. PB98-0301) for financial support.