title: Reactivity of acetoacetate with alkaline picrate: an interference of the Jaffé reaction.
abstract: Spectrophotometric, kinetic, and polarographic studies of the interaction of acetoacetate with alkaline picrate have been undertaken in the presence of aqueous NaOH concentrations ranging between 0.50 mol/L and 2.50 mol/L. Spectrophotometric data has substantiated formation of the following acetoacetate-picrate complexes: 1:1 red, 490 nm; 2:1 orange, 390 nm; and 3:1 colorless, 265 nm. Depending upon the time of measurement, the composition of alkaline picrate, and the acetoacetate level in the test samples, acetoacetate may be either a positive or negative interference in kinetic Jaffé methods for the determination of creatinine. Polarograms of alkaline picrate in 0.50 mol/L NaOH showed three well-defined nitro group reduction waves and a more diffuse fourth reduction wave with approximate half-wave potentials of -0.62 V, -0.79 V, -0.94 V, and -1.32 V, respectively. Increasing the concentration of hydroxide and/or acetoacetate resulted in the disappearance of reduction waves 1 to 3 with only reduction wave 4 remaining. Based upon the polarographic results, a trinitro anion structure has been assigned for the 2:1 acetoacetate-picrate complex.
authors.affiliation: Chemistry Department, University of Regina, Saskatchewan, Canada.
authors.forename: K G
authors.initials: KG
authors.lastname: Blass
authors.forename: D S
authors.initials: DS
authors.lastname: Ng
mesh_terms: D000090:Acetoacetates; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010851:Picrates; D011048:Polarography; D013053:Spectrophotometry
chemical_list: D000090:Acetoacetates; D010851:Picrates