Developer, plane chromatography

In the period between 1906 and 1952 there were some developments of importance. For example, the techniques of plane chromatography were developed. Earliest was the use of paper as a plane support, but when thin layers of silica gel were introduced as an alternative in the late... 

Figure 10.6. Developing chambers for plane chromatography (a) descending— used with PC (b) ascending—used with TLC and PC (c) sandwich—used with TLC (d) horizontal—used with paper as shown, but also adaptable for HPTLC.

Apart from its obvious simplicity, plane chromatography techniques require only minute amounts of samples. Moreover, chromatography on plane surfaces, rather than with a column, offers the unique advantage of two-dimensional operation. This operation exploits selective properties of two different solvents in developing a single chromatogram. 

A recent development in this field is the introduction of comprehensive two dimensional gas chromatography [100] where the entire chromatogram eluting from the primary column is submitted to a secondary column. An on-column thermal modulator collects the sample portions from one to another. The resulting two-dimensional chromatogram has peaks scattered about a plane rather than a line (orthogonal projection). This method has been tested for PCBs in an unpublished study [101]. 

Wekenborg, Susanto, and Schmidt-Traub (2004,2005) and Wekenborg (2009) applied this method to estimate the operating plane for the nonisocratic SMB separation of P-lactoglobulin A and B proteins. The isotherm is described by the steric mass action (SMA) model developed for ion exchange chromatography by Brooks and Cramer (1992) (Section 2.5.2.4). 

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