LCGC Europe-08-01-2020
Industrious Innovations in Polymer Analysis
July 31st 2020LCGC Europe spoke to Ton Brooijmans, from DSM Coating Resins in The Netherlands, about the array of innovative techniques he has recently implemented in his laboratory to analyse polymers. These include the development of a selective derivatization technique followed by size‑exclusion chromatography (SEC) to analyze polymeric carboxylic acid functionality, the benefits of non-aqueous ion‑exchange chromatography (NAIEC) for analysing synthetic macromolecules, and the important role of pyrolysis gas chromatography (Py‑GC–MS) in polymer analysis. Brooijmans also discusses future trends in this application area.
![Stability and Recovery Influences of Benzo[a]pyrene, Benzo[a]anthracene, Benzo[b]fluoranthene, and Chrysene during Sample Preparation of Plant Matrices](/_next/image?url=https%3A%2F%2Fcdn.sanity.io%2Fimages%2F0vv8moc6%2Fchroma%2Fb1144525ab2a1bd481ed407d90d9effacd96908d-1383x1041.png%3Ffit%3Dcrop%26auto%3Dformat&w=3840&q=75 "Stability and Recovery Influences of Benzo[a]pyrene, Benzo[a]anthracene, Benzo[b]fluoranthene, and Chrysene during Sample Preparation of Plant Matrices")
Quantification of European Union (EU)-priority polycyclic aromatic hydrocarbons (PAHs) in plant matrices is a crucial task. Various methods for enrichment and preconcentration, such as the preloaded-pipette tip solid‑phase extraction (SPE) (1), are available. Nevertheless, analyte recovery as a result of homogenization, sample preparation, and extraction are rarely discussed in the field of phytopharmacy. This study deals with the recovery in dry plant extracts, which are typically used in phytopharmaceuticals and reflect the actual polycyclic aromatic hydrocarbon content in the commercially available end product (2). The aim of this study was to monitor benzo[a]pyrene, benzo[a]anthracene, chrysene, and benzo[b]fluoranthene loss of spiked samples as a result of commonly-used sample pretreatment, extraction, filtering, and evaporating techniques in 1:1 (v/v) cyclohexane–ethyl acetate primulae flos and sambuci flos dry extracts. Results showed that improper sample preparation can lead to false results. In the case of benzo[a]pyrene with a deviation of 155% from the theoretical true value.
Troubleshooting LC Separations of Biomolecules, Part 2: Passivation and Mobile-Phase Additives
July 31st 2020Bioinert and biocompatible liquid chromatography (LC) systems are becoming more commonplace in laboratories, but the majority of biomolecule separations still use LC systems composed primarily of stainless steel parts. Can passivation or mobile phase additives improve separations on these systems for metal-sensitive biomolecules?
