Quantitative relationship between gas chromatographic retention time and structural parameters of alkylphenols

Alkylphenols are a group of permanent pollutants in the environment and could adversely disturb the human endocrine system.It is therefore important to effectively separate and measure the alkylphenols.To guide the chromatographic analysis of these compounds in practice,the development of quantitative relationship between the molecular structure and the retention time of alkylphenols becomes necessary.In this study,topological,constitutional,geometrical,electrostatic and quantum-chemical descriptors of 44 alkylphenols were calculated using a software,CODESSA,and these descriptors were pre-selected using the heuristic method.As a result,three-descriptor linear model(LM) was developed to describe the relationship between the molecular structure and the retention time of alkylphenols.Meanwhile,the non-linear regression model was also developed based on support vector machine(SVM) using the same three descriptors.The correlation coefficient(R2) for the LM and SVM was 0.98 and 0.92,and the corresponding root-mean-square error was 0.99 and 2.77,respectively.By comparing the stability and prediction ability of the two models,it was found that the linear model was a better method for describing the quantitative relationship between the retention time of alkylphenols and the molecular structure.The results obtained suggested that the linear model could be applied for the chromatographic analysis of alkylphenols with known molecular structural parameters.