Continuous flow spectrophotometric determination of paracetamol in pharmaceuticals following continuous microwave assisted alkaline hydrolysis.
This paper reports a continuous flow-based spectrophotometric method for the determination of paracetamol in pharmaceuticals. Dilute samples containing paracetamol are continuously hydrolysed in an alkaline medium, using a household microwave oven, to p-aminophenol, which reacts with o-cresol in 3.5 M NaOH. The blue derivative thus formed exhibits an absorbance maximum at 620 nm. The detection limit of the method is 0.2 mug ml(-1) and the system obeys Beer's law from 0.6 to 20 mug ml(-1). Repeatability was checked by calculating the R.S.D. for 11 standard solutions containing a paracetamol concentration of 4 mug ml(-1) each and found to be 1.8%. The proposed method was validated by determining paracetamol in various pharmaceutical preparations with average R.S.D. of 2.4%.
Criado
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Analytical Chemistry Division, Campus de Rabanales, University of Córdoba, E-14071 Córdoba, Spain.
Cárdenas
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Gallego
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Valcárcel
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