The Use of Pyrolysis/GCMS and Newly Developed Libraries to assist in Characterizing Complex Polymeric Samples
Poster Aug 03, 2017
There are several analytical techniques that can be used to analyze for individual components in a polymeric sample including FTIR, solvent extraction-GCMS, TGA-MS, HPLC, among others. However, these techniques do not normally lend themselves to analyze for the complete polymeric system, which includes volatile and semi-volatile compounds and the actual polymer. But using a pyrolyzer as a “thermal extracting introduction system” in combination with any industry standard GCMS provides a simple and direct means of analyzing not only the additives, but also the polymer itself. By careful selection of the sampling temperature, volatile and semi-volatile compounds may be liberated from the polymer matrix for analysis without the use of solvents or complex sample preparation. The remaining sample may then be pyrolyzed to identify the type and even structure of the polymer used in its fabrication. A typical series of analyses includes a low temperature assessment to identify volatile additives, contaminants and residuals, such as solvents and retained monomer. An intermediate temperature is used to investigate semi-volatiles like antioxidants, plasticizers and lubricants. Finally, at pyrolysis temperatures, the polymer itself may be identified and studied.
In addition, there are commercially available libraries developed to help identify different categories of additives and polymers using the search programs from the GCMS system. This poster will look at several examples of plastics and rubbers to identify the additives, residual monomers and the polymers using specially developed libraries and standard GCMS search software.
Using Elemental Analysis For Discrimination Of Pinot Noir Wines From Six Different Districts In An AvaPoster
The determination of geographical origin of wine is gaining increased interest by researchers and federal agencies around the world, partially due to increased fraud with regards to place of origin labelling. For wine, multi-elemental profiling of macro, micro, and trace elements has been proposed for determination of authenticity. Commercial wines from different wineries in 5 different neighborhoods within one AVA show characteristic elemental fingerprints. Macro, micro and trace elements as well as elemental ratios contribute to the observed separation, indicating the involvement of multiple factors and underlying mechanisms, including location and soil composition, elemental uptake by vine and rootstock, viticulture and nutrient management, water sources, and small differences in the different wineries.READ MORE
Fast arsenic speciation analysis of wines and rice with LC-ICP-QQQPoster
This method was designed in response to recent and proposed food standards, both international and national, that limit inorganic arsenic rather than total, organic, or individual arsenic species such as arsenite (AsIII) and arsenate (AsV). Analysis time is 10x faster than the current FDA regulatory method, increasing sample throughput, avoided spectral interferences and dramatically increased sensitivity. Validation data from two laboratories demonstrate the method’s accuracy and reproducibility of both wine and rice matrices in a single analytical batch.READ MORE
Proteomics and Substrate Based MS Imaging of Xenobiotic Metabolising Enzymes in Ex Vivo Human Skin and a Human Living Skin Equivalent ModelPoster
Untargeted proteomics analysis showed that human skin and a commercially available living skin equivalent model exhibit a similar distribution of xenobiotic metabolising enzymes. A new technique, substrate based mass spectrometry imaging (SB-MSI) was developed during this study.READ MORE