A reversed-phase liquid chromatographic separation with pulsed amperometric detection of phenolic acids at a glassy carbon electrode is\ndescribed. Chromatographic separation was carried out in isocratic conditions using 0.20 molÃ?·LâË?â??1 acetic acid (pH 5.0)/water (80 : 20, v/v)\nas mobile phase under constant working potential mode of 0.80 V. Chromatographic peaks presented high resolution and separation.\nCalibration curves exhibited excellent correlation coefficients, above 0.995. Linear ranges of the analytes, in mg LâË?â??1, were of 0.018ââ?¬â??18\n(gallic acid), 0.146ââ?¬â??19 (vanillic acid), 0.13ââ?¬â??17 (caffeic acid), 0.016ââ?¬â??16 (ferulic acid), and 0.008ââ?¬â??17 (p-coumaric acid), respectively. Limits of\ndetection ranged from 1.6 to 97 Ã?¼gÃ?·LâË?â??1 and precision varied in 1.73ââ?¬â??3.78% interval. Concentrations of 19Ã?±0.51mgÃ?·LâË?â??1 and 7.8Ã?±\n2.5mgÃ?·LâË?â??1 were found for vanillic and caffeic acids, respectively, in a sugarcane vinasse sample. Gallic, ferulic, and p-coumaric acids were\nnot detected. Recovery results demonstrated that the proposed method is accurate, and it can be used to detect and quantify phenolic\nacids in sugarcane vinasse without any influence of interferents.
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