Graphitized carbon correlation coefficient

Even when nitrobenzene was eliminated from the calculation, the correlation coefficient of MIPS was high for log k es> but poor for log The results indicated these graphitized carbons have different properties. It seemed to be based on the strong retention of phenol, and p-cresol, as shown in Figure 5.4, compared with the results shown in Figure 5.5. 

The hydrogen-bonding energy seemed to contribute to the retention on the graphitized carbon (Hypercarb ) column, but not to the retention on another carbon BioTechnologyResearch (BTR ) column. Therefore, only alkyl-group-substituted compounds were selected and their log k values were correlated with MI values. The correlation coefficient was 0.718 for log A ref- The log A ref values of benzene, toluene, o- grlene, m- ylene,p- g lene, o-te/t-butylphenol, 4-ethylphenol,... 

The correlation coefficient for silica was significantly improved compared to the MI values calculated using the graphitized (Hypercarb ) carbon model. The coefficients for MIPS and MIHB were 0.807 and 0.856, compared to 0.558 and 0.706 obtained with the model carbon phase. No reasonable correlation was obtained for MIES and MIVW because these interactions are not the main contributors to retention in normal-phase liquid chromatography. In terms of chromatographic behavior, phenol and p-cresol were not outliers. Their strong retention on the graphitized carbon is partly supported by the silica gel model phase. 

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