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Determination of some hydroxybenzoic acids and catechins in white wine samples by liquid chromatography with luminescence detection
Author(s) -
RodríguezDíaz Rafael Carlos,
AguilarCaballos María Paz,
GómezHens Agustina
Publication year - 2006
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.200600206
Subject(s) - chemistry , chromatography , derivatization , terbium , analyte , detection limit , protocatechuic acid , hydroxybenzoic acid , luminescence , gallic acid , wine , fluorescence , salicylic acid , chelation , high performance liquid chromatography , organic chemistry , ion , biochemistry , physics , food science , optoelectronics , quantum mechanics , antioxidant
A liquid chromatographic method with luminescence detection for the determination of eight phenolic compounds is reported. The method involves postcolumn derivatization with terbium(III). This derivatization is based on the reaction between phenolics and terbium(III) to form luminescent chelates, which were determined at λ ex 295 and λ em 545 nm using the fluorescence mode. The long wavelength emission of lanthanide chelates can minimize interferences from background sample matrix, which usually emit at shorter wavelengths. Also, the chromatographic separation allows the individual determination of phenolics, which cannot be done using the direct measurement of the fluorescence of their corresponding terbium chelates. Dynamic ranges of the calibration graphs and detection limits, obtained with standard solutions of analytes were (μg/mL): gallic acid (0.9–40, 0.3), protocatechuic acid (0.05–7, 0.016), catechin (0.2–40, 0.07), vanillic acid (0.25–40, 0.08), p ‐hydroxybenzoic acid (0.8–40, 0.25), syringic acid (0.17–40, 0.05), epicatechin (0.3–40, 0.09) and salicylic acid (0.07–12, 0.02). The precision was established at two concentration levels of each analyte and expressed as the percentage of RSD with values ranging between 1.0 and 6.5%. The practical usefulness of the method was demonstrated by the analysis of white wine samples, which were diluted two‐fold and directly injected into the chromatographic system. The recovery values obtained ranged between 93.3 and 108.0%.