Synthesis and analytical applications of 4-aminopyrazolone derivatives as chromogenic agents for the spectrophotometric determination of phenols

• Published in: Analytica chimica acta Vol. 403; no. 1; pp. 315 - 323
• Main Authors: Fiamegos, Y.C, Stalikas, C.D, Pilidis, G.A, Karayannis, M.I
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-01-2000; Elsevier
• Subjects: 4-Aminopyrazolone; Analytical chemistry; Applied sciences; Chemistry; Chromogenic agent; Exact sciences and technology; Other wastewaters; Phenols; Pollution; Spectrometric and optical methods; Spectrophotometric determination; Wastewaters; Water treatment and pollution; Greece; Chromogenic agent; Phenols; Spectrophotometric determination; 4-Aminopyrazolone; Five membered ring; Chemical analysis; Nitrogen heterocycle; Lactam; Visible spectrometry; Environmental control; Domestic waste water; Multicomponent analysis; Chromogenic reagent; Pyrazole derivatives; Benzenic compound; Water pollution; Quantitative analysis
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/S0003-2670(99)00644-3

The synthesis of simple, extensively conjugated chromophores as substitutes for 4-aminoantipyrine (4-AAP) capable of causing hyperchromic shifts when coupled with phenols is described. The 4-aminopyrazolone derivatives synthesised are subsequently applied for the spectrophotometric assay of phenolic compounds and the advantages of each of the proposed systems are highlighted. No improvement is made on the detection of
para-substituted phenols as well as polychlorophenols (e.g. pentachlorophenol). An increase in the sensitivity of coupling products is obtained for certain phenolic compounds as indicated from the comparison of the individual responses. The proposed methods have analogous analytical features and in some cases show considerable improvements compared to the 4-AAP method. Beer’s law is obeyed over a wide dynamic range (up to ca. 500
μg/l) and the relative standard deviations are <3.4%. The methods are applied satisfactorily for phenol assay in real samples, however, taking into account the intrinsic differences of the methods in the responses to the various phenolic compounds.