Determination of amodiaquine in pharmaceuticals by reaction with periodate and spectrophotometry or by high-performance liquid chromatography

Two methods are described for the determination of amodiaquine in pharmaceuticals. In the first method, amodiaquine was treated with periodate at pH 7.5-8.5 to yield a chromogen, which is believed to be a 1,4-benzoquinone imine derivative, and extracted into chloroform for spectrophotometric assay. The maximum molar absorptivity was found to be 2.17 x 10(3) l mol-1 cm-1 at 442 nm. Primaquine and chloroquine, if present also, do not interfere. The second method, which was used for the simultaneous determination of amodiaquine, primaquine and chloroquine, is based on high-performance liquid chromatography on an octadecylsilane column using a mobile phase of methanol-water (80 + 20) containing 0.5% anhydrous acetic acid and an over-all concentration of sodium dodecyl sulphate of 0.5 mM, with detection at 340 nm.