Extraction of plant growth regulators present in Kappaphycus alvarezii sap using imidazolium based ionic liquids: detection and quantification by using HPLC-DAD technique

Abstract

Three different imidazolium based ionic liquids namely 1-butyl-3-methylimidazolium hexafluorophosphate [Bmim][PF₆], 1-methyl-3-octylimidazolium tetrafluoroborate [Omim][BF₄] and 1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide [Bmim][NTf₂] were used to extract plant growth regulators (PGRs) present in the sap (K-sap) obtained by the mechanical expulsion from the fresh Kappaphycus alvarezii seaweed. [Bmim][PF₆] was able to extract up to 65% of the total trans-zeatin and about 18% of the total indole-3-acetic acid (IAA) present in the sap as estimated by using a HPLC-DAD (diode array detector). However [Bmim][NTf₂] was not able to extract any of the PGRs. Furthermore, addition of [Omim][BF₄] to the sap resulted in the formation of an instant white precipitate with trans-zeatin preferentially bound on it. From the overall studies, it was concluded that [Bmim][PF₆] can be effectively used to extract PGRs from seaweeds or plant extracts.