Highlights In Separation Science

An obvious highlight for separation scientists on the last day of the Analytica Conference in Munich, Germany, was literally the “Highlights in Separation Science” session chaired by Martin Vogel from the Karst Research Group at the University of Munster in Germany.

Munich sunset panoramic architecture, Bavaria, Germany. | Image Credit: © Travel Faery - stock.adobe.com

Michael Laemmerhofer from the University of Tuebingen, Germany presented an illuminating lecture entitled “Chiral Stationary Phases for Isomer Separations in Bioanalytical and Biopharmaceutical Applications”. Laemmerhofer gave an overview of the historical development of chiral stationary phases and demonstrated the benefits of combining chiral stationary phases (CSPs) with mass spectrometry (MS) in lipidomics and metabolomics applications. The value of multidimensional liquid chromatography to analyse complex mixtures by combining achiral chemoselectivity with the stereoselectivity of CSPs was described in an application to determine the absolute configuration of a natural product with a tetrapeptide structure. An interesting example illustrating the benefits of coupling ion mobility mass spectrometry (IM-MS) with CSPs to confirm enantioselective amino acid profiles in about 1 min was also described.

The next presentation was on the “Speciation of Polydimethysiloxanes with SEC Coupled to ICP-OES/MS to Solve Industrial Challenges” by Kerstin Vogel from the Dow Deutschland Anlagengesellschaft in Germany.

Vogel highlighted the benefits of size exclusion chromatography (SEC) combined with triple quadrupole inductively coupled plasma mass spectrometry QQQ-ICP-MS in terms of high sensitivity and large linear ranges that can be achieved compared to size exclusion chromatography (SEC) combined with inductively coupled plasma optical emission spectrometry (ICP-OES) to analyze polydimethysiloxanes (PDMAs).

Vogel described the numerous challenges she encountered to develop this novel approach and illustrated the benefits with a method involving the characterization of organosilicon compounds as well as the potential and limitations of this technique. The new method was used to calculate silicon distribution against molecular weight at sub-ppb levels and could quantify a wide variety of organic silicon-components. Vogel concluded that SEC–QQQ-ICP-MS could be useful in applications where information on the chemical composition of (complex) element organic-polymers is required and could lead to new directions in polymer characterization research.

Gertrud Morlock from Justus Liebig University Giessen in Germany followed this talk with talk called “Sustainable Future Is Now: The First of its Kind 2LabstoGo System for Everyone, Everywhere”. Morlock described a novel, miniaturized open-source system called2LabsToGo that combines the qualities of five cutting-edge areas: biology, chromatography, open-source access, 3D printing, and sustainability.

Morlock emphasized that the portable 2LabsToGo system consolidates two fully equipped laboratories in one system and offers low-cost analysis. The system has been used to analyse food and beverages, perfumes, and cosmetics and no sample preparation is required. The planar multiplex bioassays that the system uses gives the analyst the ability to differentiate agonistic, antagonistic, false-positive, cytotoxic, and synergistic responses in the same analysis, according to Morlock. The system is also customizable to the analysts needs she added. Morlock also described the development and advantages of a low-cost 3D-printed autosampler with mini valve/pump. Morlock concluded that the 2LabsToGo system can obtain useful informationabout unknown compounds and incorporate automated high-resolution mass spectra.

Joachim Weiss from the Leopold-Franzens University, Institute of Analytical Chemistry and Radiochemistry, Austria concluded the session with a highly informative and entertaining account on the evolution of ion chromatography.

Weiss asserted that ion chromatography (IC) has emerged as the main method for analyzing inorganic and organic ions, particularly for water samples. Traditional IC relies on ion-exchange separations of the ionic analytes coupled with suppressed conductivity detection. Standard detection limits in the single-digit µg/L range have been achieved using direct injection techniques, according to Weiss.

However, to detect perchlorate at concentrations below 1 µg/L in samples containing high levels of electrolytes, direct injection methods are insufficient, according to Weiss. He described the advantages of heart-cutting technique (IC×IC) an alternative to IC-MS. The IC×IC method offers a specific major advantage: large sample volumes can be injected onto the first-channel, high-capacity separator column with only filtration as sample preparation, simplifying analysis significantly. This approach achieves detection limits comparable to IC-MS for perchlorate and other emerging contaminants like bromate, according to Weiss.

He concluded the talk by describing the benefits of coupling ICP with IC s to detect metals with varying oxidation states and an innovative IC‒MS/MS. application to detect polar pesticides at trace levels in food products.