Chromatography column behavior

The first aqueous chemistry of mtherfordium showed that it eluted from liquid chromatography columns as a 4 + ion, consistent with its position in the periodic table as a d-block element rather than a trivalent actinide. Gas chromatography of the mtherfordium halides has shown the volatility sequence ZrCl4 > RfCLt > HfCl4 with a similar sequence for the tetrabromides (Fig. 15.16). Thus, mtherfordium does not follow the expected periodic table trend nor is its behavior in accord with relativistic calculations. 

A whole-column detection system fabricated with parts from a typical A4 size optical scanner was used to monitor peak crossover that occurs when a solute moves slower than another one, then during gradient elution, migrates faster and reaches the column outlet earlier. A 0.3-mm spatial resolution and a 3.6 ms temporal resolution were obtained and proved adequate for directly monitoring solute retention behavior in a liquid chromatography column under IPC conditions [57]. On line radiochemical detection was also explored [58]. 

C. S. Wong and A. W. Garrison, Enantiomer separation of polychlorinated biphenyl atropisomers and polychlorinated biphenyl retention behavior on modified cyclodextrin capillary gas chromatography columns, /. Chromatogr. A 866 213 (2000). 

These values are practically temperature independant, and they are very close to those found for the Apiezon L column. Comparison with the values of a series of alkybenzenes shows that the 5-position of thiazole possesses behavior analogous to that of a benzenic position in gas-liquid chromatography. 

T. L. Chester and J. D. Pinkston, Pressure-regulating fluid interface and phase behavior considerations in the coupling of packed-column supercritical fluid chromatography with low-pressure detectors , ]. Chromatogr. 807 265-273 (1998). 

In multi-residue analysis, an analyte is identified by its relative retention time, e.g., relative to aldrin when using ECD or relative to parathion or chlorpyrifos when using a flame photometric detection (FPD) and NPD. Such relative retention times are taken from corresponding lists for the columns used. Further evidence for the identity of an analyte is provided by the selectivity of the different detectors (Modules D1 to D3), by its elution behavior during column chromatography (Modules Cl and C2) and in some cases even by the peak form in a gas chromatogram. In a specific analysis for only some individual analytes, their retention times are compared directly with the corresponding retention times of the analytes from standard solutions. 

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