Retention Indices As the Best Reproducible Chromatographic Parameters for the Characterization of Phenolic Compounds in Reversed-Phase High-Performance Liquid Chromatography

Abstract

A comparison of various methods for presenting the retention parameters of analyzed compounds in reversed-phase HPLC under the conditions of stepwise gradient elution demonstrated that retention indices (RIs) based on a standard scale of n -alkyl phenyl ketones exhibited the best reproducibility. However, a new procedure for calculating extrapolated RI values under these conditions should be developed for determining the RIs of the most hydrophilic compounds, which are eluted from a column before a reference component (acetophenone). With this procedure, the RIs of more than 40 phenolic and polyphenolic compounds were determined. The addition of spectroscopic characteristics to these RIs was responsible for the reliable identification of the above compounds in complex mixtures of extractive substances of plant origin. Program for calculating linear-logarithmic retention indices [12]REM: PROGRAM for calculation of lin-log retention indices REM: SIMPLEST VERSION REM: you need data about three reference compounds PRINT: "Calculation of lin-log retention indices (from exp. ret. times)"

Competitive role of structural properties of titania–silica mixed oxides and a mechanistic study of the photocatalytic degradation of phenol

“…•OH radical attack on phenol leads to the formation of several intermediates such as hydroquinone (HQ), catechol (CC), pyrogallol (PG), hydroxyhydroquinone (HHQ), resorcinol (RC), muconic acid (MU), p-benzoquinone (p-BQ), o-benzoquinone (o-BQ), and hydroxybenzoquinone (HBQ) [43,[66][67][68][69].…”

Characterization of the composition and antioxidant activity of plant extracts by HPLC with UV and amperometric detection

“…It was interesting to compare the quantitative and qualitative composition of the phenolic fraction of the extracts and their antioxidant activity. Natural phenolic compounds (aromatic and polyaromatic compounds containing a phenolic hydroxyl [11]) were identified using a previously compiled database [12]. The database contained spectral and chromatographic properties for 74 phenolic compounds including aromatic alcohols, aldehydes, acids, methoxy-and acylated derivatives, flavanoids and their glycosides, coumarins, and furocoumarins.…”

A Kinetic Study of Photocatalytic Degradation of Phenol over Titania–Silica Mixed Oxide Materials under UV Illumination

“…There are several intermediates of degraded phenol that have toxicity in the environment reported in the existing literature [44]. In particular, the addition of hydroxyl radical resulted in hydroxy benzenes, and these intermediate species can further oxidize and lead to the highly substituted intermediates and the acidic intermediates after the cleavage of the ring [45][46][47]. The HPLC results provide a broader picture regarding the intermediates that formed under our experimental conditions, and it was further validated by the APCI-MS studies explained in the subsequent section.…”