title: Selective on-line detection of boronic acids and derivatives in high-performance liquid chromatography eluates by post-column reaction with alizarin.
abstract: An on-line high-performance liquid chromatography (HPLC) method for the rapid and selective detection of boronic acids in complex mixtures was developed. After optimization experiments at an HPLC flow rate of 0.40 mL/min, the HPLC-separated analytes were mixed post-column with a solution of 75 μM alizarin and 0.1% triethylamine in acetonitrile, which was delivered at a flow rate of 0.60 mL/min. The reaction between alizarin and boronic acids occurred in a reaction coil of dimensions of 3.5 m × 0.25 mm at a temperature of 50 °C, resulting in fluorescent complexes that were detected as positive peaks by a fluorescence detector (λexc 469 nm and λe m 610 nm). The method enabled the selective detection of various boronic acids and derivatives, with a limit of detection of phenylboronic acid of 1.2 ng or 1 μM. It could successfully monitor the progress of two organic reactions involving boronic acid-containing compounds, and provided useful insights into the course of the reactions.
authors.affiliation: Laboratory of Organic Chemistry, Wageningen University, Dreijenplein 8, 6703 HB Wageningen, The Netherlands.
authors.forename: Florine
authors.initials: F
authors.lastname: Duval
authors.affiliation: Laboratory of Organic Chemistry, Wageningen University, Dreijenplein 8, 6703 HB Wageningen, The Netherlands.
authors.forename: Puspita A
authors.initials: PA
authors.lastname: Wardani
authors.affiliation: Laboratory of Organic Chemistry, Wageningen University, Dreijenplein 8, 6703 HB Wageningen, The Netherlands.
authors.forename: Han
authors.initials: H
authors.lastname: Zuilhof
authors.affiliation: Laboratory of Organic Chemistry, Wageningen University, Dreijenplein 8, 6703 HB Wageningen, The Netherlands. Electronic address: Teris.vanBeek@wur.nl.
authors.forename: Teris A
authors.initials: TA
authors.lastname: van Beek
mesh_terms: D000880:Anthraquinones / Q000737:chemistry*; D001897:Boronic Acids / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D057230:Limit of Detection
chemical_list: D000880:Anthraquinones; D001897:Boronic Acids; D005456:Fluorescent Dyes; C004468:Alizarin Red S; C010686:benzeneboronic acid
keywords: Alizarin red S; Boronate; Fluorescence; Post-column derivatization; RP-HPLC; Suzuki reaction