Matthias Rainer | Authors


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.

Advanced Profiling Method based on MELDI–MS For High-Throughput Pattern Analysis in Proteomics

A new proteomic profiling method based on material-enhanced laser desorption/ionization (MELDI) has been developed to identify candidate biomarkers that are selected in MELDI mass profiles. The basic principle of applying MELDI is to trace out the low-concentration species generated as a result of disease, which can then be used as diagnostic markers after their authentic validation. The first step of the MELDI approach is applied to reduce the complexity of proteomic samples by specific binding of serum proteins onto chemically modified MELDI beads, which are then directly analysed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). The resulting mass profiles provide the basis for differentiating diseased samples from control samples. The use of liquid handling robots for sample preparation for high-throughput applications leads to higher reproducibility, which is crucial to succesfully identify disease markers. The ongoing development of MELDI for the..