title: Difference spectrophotometric assay of 5-hydroxymethylfurfuraldehyde in hydrolysed pharmaceutical syrups-II. Isoniazid reagent.
abstract: A rapid difference spectrophotometric assay of 5-hydroxymethylfurfuraldehyde (5-HMF) in certain degraded syrups is described. The method involves the measurement of the difference absorbance at 340 nm of the isonicotinoyl hydrazone of 5-HMF, formed at room temperature in an acidic solution of isoniazid, relative to an equimolar solution of 5-HMF, which has been reduced by sodium borohydride, and isoniazid reagent. The procedure is accurate, precise and selective for 5-HMF in the syrups examined. The limits of detection and determination are 0.91 mug ml(-1) and 12.4 mug ml(-1), respectively. The method has been applied to codeine linctus, paracetamol elixir (paediatric) opiate squill linctus, ipecacuanha and squill linctus, Phensedyl Linctus and invert syrup.
authors.affiliation: Department of Pharmacy, University of Strathclyde, George Street, Glasgow G1 1XW, UK.
authors.forename: A G
authors.initials: AG
authors.lastname: Davidson
authors.forename: T O
authors.initials: TO
authors.lastname: Dawodu