Optimization of the separation of chlorophenols with stepwise gradient elution in reversed phase liquid chromatography

✍ Scribed by Mohammad Reza Hadjmohammadi; Kamyar Kamel; Mohammad Hosein Fatemi

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 430 KB
• Volume: 30
• Category: Article
• ISSN: 1615-9306
• DOI: 10.1002/jssc.200700095

✦ Synopsis

An optimization technique based on gradient elution was used to separate eleven chlorophenols by reversed phase liquid chromatography. The separation was based on gradient elution with a stepwise variation pattern of the volume fraction of organic modifier, phi, in the mobile phase. Initially, two-, three-, and four-parameter equations which describe the dependence of ln k' upon phi, were examined for their ability to fit the experimental data. It was found that, among these equations, the four-parameter equation gave the best fit of the experimental data. In addition to separation optimization, a non-linear least squares program with a grid search for initial estimates was used to determine the best variation pattern. The best variation pattern was obtained with phi(1)= 0.27, phi(2)= 0.39, phi(3)= 0.62, t(1) = 33 min, and t(2) = 11 min. This pattern allowed the chromatographic separation of the chlorophenols with a good resolution and a total analysis time of 51 min. Good agreement was observed between predicted and experimental values of the retention times under optimal condition.