Potential of Capillary Electrophoresis for the Profiling of Propolis

Advances in the analysis of phenolic compounds in products derived from bees

“…This process should remove the inert material and preserve the polyphenolic fractions. Extraction with ethanol is particularly suitable to obtain dewaxed propolis extracts rich in polyphenolic components [100] and this is the most commonly used solvent, especially at concentrations of 70% [101][102][103][104][105][106][107][108] and 80% [109][110][111][112][113][114], although other concentrations have also been used, such as 95% [115] and absolute ethanol [116,117]. Compared with absolute ethanol, extraction with aqueous ethanol results in wax-free tinctures, containing higher amounts of phenolic substances [118].…”

Recent trends in the determination of polyphenols by electromigration methods

“…It must be noted that until now practically no attention has been paid to possible oxidation of rather reactive polyphenols with oxygen in alkaline BGEs. A tendency of using organic solvents (such as methanol and acetonitrile) as modifiers for improving efficiency in both CZE and MEKC is also notable [14,17,18,20,21,25,[29][30][31][32]44,[52][53][54]60]. Furthermore various types of cyclodextrins (CDs) were employed as components of the BGEs acting as chiral selectors or just improving the efficiency of separation of non-chiral analytes [16].…”

“…In the MEKC of polyphenols sodium dodecylsulphate is the most widely used surfactant as can be traced in the data of Table 1 [17,19,21,22,26,29,49,54,59,60]. Sodium cholate (SC) was reported as an auxiliary additive to SDS-containing BGE in the so called "mixed MEKC".…”

Concurrent analysis of nucleoside reverse transcriptase inhibitors in a pool of endogenous nucleosides by short-end injection-capillary electrochromatography on a β-cyclodextrin-bonded stationary phase

“…At low ionic strength (5 mM, for instance), the positively charged nucleosides strongly interact with the silanol groups, leading to substantial retention times and retention factors. As the ionic strength of the buffer (TEAA) increases, so does the triethylammonium concentration, giving rise to an ionic competition with the cationic nucleosides towards the silanophilic interactions [32,33]. Thus, the triethylammonium cations behave like competing agents and the retention of the charged nucleosides is decreased.…”