XAD-2-A useful alternative to Tenax TA for analysis of biogenic volatiles employing thermal desorption coupled with gas chromatography-mass spectrometry was written by Marcillo, Andrea;Jakimovska, Viktorija;Widdig, Anja;Birkemeyer, Claudia. And the article was included in Journal of Chromatography A in 2017.Application In Synthesis of 2,3,4,5,6-Perfluoropyridine The following contents are mentioned in the article:
Volatile organic compounds (VOCs) are commonly collected from gaseous samples by adsorption to materials such as the porous polymer Tenax TA. Adsorbed compounds are subsequently released from these materials by thermal desorption (TD) and separated then by gas chromatog. (GC) with flame ionization (FID) or mass spectrometry (MS) detection. Tenax TA is known to be particularly suitable for nonpolar to semipolar volatiles, however, many volatiles from environmental and biol. samples possess a rather polar character. Therefore, the authors tested if the polymer XAD-2, which so far is widely used to adsorb organic compounds from aqueous and organic solvents, could provide a broader coverage for (semi)polar VOCs during gas-phase sampling. Mixtures of volatile compounds covering a wide range of volatility (b.p. 20-256°) and different chem. classes were introduced by liquid spiking into sorbent tubes with one of the two porous polymers, Tenax TA or XAD-2, and analyzed by TD/GC-MS. At 1st, an internal standard mixture composed of 17 authentic standards was used to optimize desorption temperature with respect to sorbent degradation and loading time for calibration. Secondly, the authors tested the detectability of a complex standard mixture composed of 57 volatiles, most of them common constituents of the body odor of mammals. Also, the performance of XAD-2 compared with Tenax TA was assessed as limit of quantitation and linearity for the internal standard mixture and 33 compounds from the complex standard mixture Volatiles were analyzed in a range between 0.01-∼250 ng/tube depending on the compound and material. Lower limits of quantitation were 0.01-3 ng ± <25% relative standard deviation (R2 > 0.9). The authors found different kinetics for compound adsorption with XAD-2, and a partially better sensitivity in comparison with Tenax TA. For these analytes, XAD-2 might be recommended as an alternative of Tenax TA for TD/GC-MS anal. This study involved multiple reactions and reactants, such as 2,3,4,5,6-Perfluoropyridine (cas: 700-16-3Application In Synthesis of 2,3,4,5,6-Perfluoropyridine).
2,3,4,5,6-Perfluoropyridine (cas: 700-16-3) belongs to pyridine derivatives. Pyridines are an important class of heterocycles and occur in polysubstituted forms in many naturally occurring biologically active compounds, drug molecules and chiral ligands. Many analogues of pyridine are known where N is replaced by other heteroatoms . Substitution of one C–H in pyridine with a second N gives rise to the diazine heterocycles (C4H4N2), with the names pyridazine, pyrimidine, and pyrazine.Application In Synthesis of 2,3,4,5,6-Perfluoropyridine