Browsing by Author "Mohammed, Saada"

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    The use of compounds chemically related to analyte as surrogate reference standards in quantitative HPLC
    (2008-08-05) Mohammed, Saada
    The possibilities of using compounds chemically related to analyte as surrogate reference standards in quantitative high performance liquid chromatography (HPLC) have been explored. A quantitative high performance liquid chromatography method has been developed to determine a constant (K) with a surrogate reference that makes it possible to analyse paracetamol in a formulation in the absence of pure paracetamol as reference. Caffeine was used as internal standard while aspirin, phenacetin and benzoic acid were considered as surrogate references. The chromatographic apparatus consisted of Zobax C-18 column, UV detector at 257 nm and computer (Chromquest software) as a recorder. Elution was isocratic with a mobile phase consisting of methanol and 2.5% acetic acid 2:3. The retention times of the analyte were: 3.0 ± 0.01 mins (paracetamol), 4.7 ± 0.02 mins (caffeine), 8.1 ± 0.03 mins (aspirin), 11.1 ± 0.06 mins (phenacetin) and 11.7 ± 0.05 mins (benzoic acid). The constant K for the pure standards obtained were, aspirin: 18.23 ± 0.048, phenacetin: 1.15 ± 0.051 and benzoic acid: 11.66 ± 0.251. These constants were used in the analysis of nine samples of paracetamol tablets. The percentage content obtained for each sample was then compared with that obtained using the BP and the USP methods. The results showed that the surrogate reference standard can be used for the analysis of paracetamol without the use of pure paracetamol powder as reference.