Determination of pKa Values of Some Auxins in Methanol-Water Mixtures by Reversed Phase Liquid Chromatography and Potentiometric Methods

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Kelen M., Sanli N.

JOURNAL OF THE BRAZILIAN CHEMICAL SOCIETY, vol.20, no.1, pp.133-140, 2009 (SCI-Expanded) identifier identifier


Plant hormones are of vital importance for the normal functioning of plants. Auxins are a class of phytohormones involved in many aspects of plant growth. Indole-3-acetic acid, (IAA), indole-3-pyruvic acid (IPA) and indole-3-lactic acid (ILA) are auxins with biological functions stimulating growth processes such as cell elongation and division. In this study, the pK(a) values of IAA, IPA and ILA in 30%, 40% and 50% (v/v) methanol-water mixtures were determined using potentiometry, liquid chromatography (LC) and LC-DAD methodology. Also, the pK(a) values in water predicted by the SPARC on-line calculator have been investigated.