Correlation chromatography

Now that we have discussed the theoretical basis for correlation chromatography, let us examine some areas which may cause problems or at least, in practice, limit its application. 

For the reader who is interested in pursuing the mathematical details of CC, I recommend the papers of Smit and his co-workers (15) These researchers published early in the area of CC (16) and continue to contribute regularly to the field (17) Phillips has also been active in the field of CC, which he considers to be a subset of what he calls, multiplex chromatography (18). Some workers have used on-line correlation chromatography to study the thermal decomposition of polymers and compared the results against those using conventional injection procedures (19), while others have applied it to the study of gas-solid adsorption (20) ... 

Correlation Chromatography (CC) can be considered a typical example of an active or on-line chemometrie technique. Impossible without computers, it shows promising results in (ultra) trace analysis. This paper will describe two directions that utilize correlation techniques a semi-continuous kind of chromatography ( ) and an extension of the limit of detection in trace analysis ( 2 ). Correlation Chromatography will be shown to be a powerful method for application in (ultra) trace analysis. 

Analytical model, assumptions and practical implications, 52-57 Analytical performance, correlation chromatography, 108 Analytical process, steps of, 7 Aroclors, isomer-specific analysis of, application of SIMCA, 195-232 Atomic absorption spectrometry, determination of iron in water, 116... 

Fig. 10. Calibration graph for phenol with fluorimetric detection for 5 concentrations (I0" to lO" gl ) s indicates single injection and c indicates correlation chromatography. The numbers below the data points indicate the correlation time (minutes) (ppt = ng 1" ). The bars represent 3 x standard deviation of the integrated noise (confidence interval).

An extension of CC is Simultaneous Correlation Chromatography (SCC) (Smit et al. Fig. 13 shows an experimental set up. Three samples with naphthalene, anthracene and l,2-ben2anthracene are simultaneously injected, however, each controlled by a sequence uncorrelated with the others. The result is shown in Fig. 14. The peaks of naphthalene are used to construct a calibration line. The advantages are twofold The random fluctuations are reduced by multiple injection and averaging property, and both an unknown sample and calibration samples are measured simultaneously under exactly the same conditions, drift and uncertainty are reduced to a high extent. 

Fig. 15. Chromatograms of degradation products of polycaproamide by pyrolysis correlation chromatography.

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