Polycyclic aromatic hydrocarbon separation

Poole, C. F., Butler, M. E., Coddens, M. E., Khatib, S., and Vandervennt, R. (1984). Comparison of methods for separating polycyclic aromatic hydrocarbons by high performance thin layer chromatography. J. Chromatogr. 302 149-158. 

Bota et al. [84] used the PCA method to select the optimum solvent system for TLC separation of seven polycyclic aromatic hydrocarbons. Each solute is treated as a point in a space defined by its retention coordinates along the different solvent composition axes. The PCA method enables the selection of a restricted set of nine available mobile phase systems, and it is a useful graphical tool because scatterplots of loading on planes described by the most important axes will have the effect of separating solvent systems from one other most efficiently. 

Figure 4.4 Separation of SRM 1647 and SRH 869 polycyclic aromatic hydrocarbon test mixtures on a monomeric and polymeric reversed-phase octadecylsiloxane bonded phases by gradient elution. (Reproduced with permission from ref. 69. Copyright American Chemical Society).

Because process mixtures are complex, specialized detectors may substitute for separation efficiency. One specialized detector is the array amperometric detector, which allows selective detection of electrochemically active compounds.23 Electrochemical array detectors are discussed in greater detail in Chapter 5. Many pharmaceutical compounds are chiral, so a detector capable of determining optical purity would be extremely useful in monitoring synthetic reactions. A double-beam circular dichroism detector using a laser as the source was used for the selective detection of chiral cobalt compounds.24 The double-beam, single-source construction reduces the limitations of flicker noise. Chemiluminescence of an ozonized mixture was used as the principle for a sulfur-selective detector used to analyze pesticides, proteins, and blood thiols from rat plasma.25 Chemiluminescence using bis (2,4, 6-trichlorophenyl) oxalate was used for the selective detection of catalytically reduced nitrated polycyclic aromatic hydrocarbons from diesel exhaust.26... 

Yang, W.-H., Chen, I-L., and Wu, D.-H., Chemically bonded phenylsilicone stationary phases for the liquid chromatographic separation of polycyclic aromatic hydrocarbons and cyclosiloxanes, /. Chromatogr. A, 722, 97, 1996. 

Polycyclic aromatic hydrocarbons (PAH) are important air pollutants that have to be detected at very low concentrations. Fig. 2.4h shows the separation of a synthetic mixture of very low levels of PAH. They are barely detectable using uv absorption, but are easily monitored by fluorescence. 

Wise, S. A. and Sander, L. C. 1985. Factors affecting the reversed-phase liquid chromatographic separation of polycyclic aromatic hydrocarbon isomers. J. High Resolut. Chromatogr. Commun. 8 248-255. 

Example 2 Separation of a polycyclic aromatic hydrocarbon and an alkyl benzoate. The logP values of fluorene and butyl benzoate are 3.91 and 3.74, respectively, from Table 4.1. The separation is poor in 50% aqueous aceto-... 

One component of the eluent should have properties similar to those of the analytes, and this solvent is diluted by another solvent to control the retention time. The basic idea can be understood from the chromatographic behaviour of phthalic acid esters and polycyclic aromatic hydrocarbons (PAH). This approach can be applied to the separation procedure for a variety of stationary phase materials, including silica gel, polystyrene gel, and ion-exchangers. 

Wise, S.A. and Sander, L.C., Molecular shape recognition for polycyclic aromatic hydrocarbons in reversed-phase liquid chromatography, in Jinno, K. (Ed.), Chromatographic Separations Based on Molecular Recognition, Wiley-VCH, Inc., New York, 1997, p. 1. 

Janini, GM., Muschik, G.M., Schroer, J.A., and Zielinski, W.L., Gas-liquid-chromatographic evaluation and gas-chromatography mass spectrometric application of new high-temperature hquid-crystal stationary phases for polycyclic aromatic hydrocarbon separations. Ana/. Chem., 4S, 1879, 1976. 

Janini, G.M., Muschik, G.M., andZielinski, W.L., A,A -i>w[para-butoxybenzylidene)-alpha,alpha -bi-para-toluidine—thermally stable liquid-crystal for unique gas-liquid-chromatography separations of polycyclic aromatic-hydrocarbons, Anal Chem., 48, 809, 1976. 

Another area where negative ion chemical ionization has been applied in our laboratory is for the analysis of polycyclic aromatic hydrocarbons. Separation of these... 

Polycyclic aromatic hydrocarbons represent a group of compounds that is most frequently separated by using silica or alumina as the stationary phase (cf. Figs. 2 and 8). The separation of 25 of the most important polynuclear aromatic hydrocai bolls 49) is illustrated In Fig. 14. To en-... 

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