Evaluation of the coupling between ultra performance liquid chromatography and evaporative light scattering detector for selected phytochemical applications

Abstract

Evaluation of the coupling between ultra performance liquid chromatography and evaporative light scattering detector for selected phytochemical applications Fast analysis in LC can be performed with sub-2 lm particles at very high pressures (up to 1000 bar) known as ultra performance LC (UPLC). With this configuration, it is possible to obtain fast and/or highly efficient separations compared to conventional LC. For the analysis of compounds without chromophores, the evaporative light scattering detector (ELSD) is an attractive alternative because of its quasi-universality, versatility, low-cost and good sensitivity. The UPLC -ELSD was investigated in terms of sensitivity and apparent efficiency, with a conventional ELSD instrument, for two types of commercially available nebulisers, using different mobile phase flow rates and column ids. Results were finally compared with the UPLC -UV configuration. Three applications with phytochemical compounds were selected to highlight the potential of this approach (i.e. the isocratic separations of artemisinin and its derivatives, of calystegines and the gradient separation of several tropane alkaloids). Depending on the used column length, baseline separations were obtained in 3 -10 min, with an average apparent efficiency ranging from 7000 to 30 000 plates.

Characterization of the efficiency of microbore liquid chromatography columns by van Deemter and kinetic plot analysis

“…For the determination of efficiency by van Deemter analysis the retention factor should be constant for all investigated columns. Thereby, the results are directly comparable because the influence of k on N can be neglected . This is especially important for small i.d.…”

Tropane alkaloid analysis by chromatographic and electrophoretic techniques: An update

“…For tropane alkaloids from plant extracts, Russo and colleagues [127] compared the separation and detection of scopolamine, 6␤-OH-hyoscyamine, hyoscyamine, and littorine by UPLC-UV and UPLC-ELSD (evaporative light scattering detector) on RP-C18 columns of various dimensions (2.1 mm × 30 mm, 2.1 mm × 50 mm, 2.1 mm × 100 mm, 1 mm × 50 mm) filled with 1.7 m particles. The solvent gradient rose from 10 to 15% acetonitrile in aqueous solution (trifluoroacetic acid 0.1% v/v) within 4 min for the 2.1 mm × 50 mm column and within 8 min for the 2.1 mm × 100 mm column.…”

Rapid resolution liquid chromatography for monitoring the quality of stockpiled atropine preparations for injection

“…The EP tests for eight impurities (Imp), i.e. Russo et al [12] described the analysis of scopolamine, 6-b-OH-hyoscyamine and littorine in plant extracts by UHPLC-UVin comparison with UHPLC-ELSD (evaporative light scattering detection)using RP 18 columns (1.7 mm, lengths: 50 and 100 mm) with acetonitrile/ trifluoracetic acid. This method [5] replaces the TLC (thin-layer chromatography) method described earlier [6] and the HPLC method that was described in a monograph on atropine [7] with a column size of 125 x 4 mm and a particle size of 4 mm (and a similar mobile phase).…”

“…The chromatography was performed on novel fused core particles (2.7 mm; column 50 x 2.1 mm) with a gradient of aqueous formic acid and methanol. Russo et al [12] described the analysis of scopolamine, 6-b-OH-hyoscyamine and littorine in plant extracts by UHPLC-UVin comparison with UHPLC-ELSD (evaporative light scattering detection)using RP 18 columns (1.7 mm, lengths: 50 and 100 mm) with acetonitrile/ trifluoracetic acid. In a review article, Aehle and Draeger [13] summarized the state-of-the-art of chromatographic and electrophoretic analysis of tropane alkaloids.…”