Publications by authors named "Anna Lipphardt"

2 Publications

  • Page 1 of 1

Hyphenation of supercritical fluid chromatography with different detection methods for identification and quantification of liamocin biosurfactants.

J Chromatogr A 2020 Sep 24;1631:461584. Epub 2020 Sep 24.

Institute of Inorganic and Analytical Chemistry, University of Münster, D-48149 Münster, Germany. Electronic address:

Liamocins are a class of biosurfactants with growing interest. However, methods for identification and quantification of liamocins on the molecular level are lagging behind. Therefore, we developed a chromatographic separation based on supercritical fluid chromatography (SFC) for liamocins and structurally related exophilins. The different congeners could be separated on a charge modulated hydroxyethyl amide functionalized silica-based column. Coupling to high-resolution mass spectrometry (MS) revealed four exophilin species and four liamocin species with mannitol and arabitol as polyol head group in a sample of the yeast-like fungus Aureobasidium pullulans (A. pullulans). In contrast to a recently published reversed phase high-performance liquid chromatography (HPLC) method, the different subclasses (exophilins, mannitol liamocins and arabitol liamocins) were additionally separated by means of SFC. The structures were confirmed by their accurate masses and tandem mass spectrometry (MS/MS). A complementary quantification method was developed using SFC coupled to charged-aerosol detection (CAD) to overcome the disadvantages of quantification by means of MS without authentic standards. A flow compensation by varying the make-up flow was used to obtain a constant composition of the mobile phase during detection and to ensure a stable detector response. The concentrations of the individual liamocin species were determined using an external calibration with n-octyl-β-d-glycopyranoside. The total amount of these concentrations agrees with the dry weight of an aliquot of the heavy oil. The developed SFC-based method has the advantage of shorter analysis time and superior selectivity compared to the previously published LC separation. In brief, the here presented SFC hyphenations enable comprehensive analysis of liamocin biosurfactants providing identification and absolute quantification of individual congeners.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chroma.2020.461584DOI Listing
September 2020

Forensic DNA phenotyping legislation cannot be based on "Ideal FDP"-A response to Caliebe, Krawczak and Kayser (2017).

Forensic Sci Int Genet 2018 05 9;34:e13-e14. Epub 2018 Feb 9.

University College Freiburg, Albert-Ludwigs-Universität Freiburg, Bertoldstraße 17, 79098 Freiburg, Germany. Electronic address:

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.fsigen.2018.01.009DOI Listing
May 2018
-->