Simultaneous determination of citalopram, paroxetine, fluoxetine, and sertraline by high-temperature liquid chromatography

A lack of serotonin in the brain is associated with depression. Selective serotonin reuptake inhibitors (SSRIs) are widely used to help treat depression and associated symptoms. A method has been developed for the simultaneous determination of SSRIs by high-temperature liquid chromatography (HTLC). Citalopram, paroxetine, fluoxetine, and sertraline compounds, which are widely used as antidepressant active agents, have been chosen as SSRIs. The separation of the SSRIs have been carried out by using four different column types, including XTerra MS C18, Zorbax SB-Phenyl, Alltima C18 and Phenyl Hypersil columns, and their chromatographic performances have been evaluated. The best separation has been obtained on the Zorbax SB-Phenyl column (150 mm × 4.6 mm, 5 μm) among the four different columns studied. The separation temperature and the composition of mobile phase were examined for the optimization of chromatographic separation. Chromatographic separation of SSRIs has been carried out at temperatures ranging from 100 to 200 °C with variable flow rates (0.5-1.5 mL/min). Water:acetonitrile:acetic acid mixtures containing with 10 or 20% acetonitrile and 2% acetic acid have been used as mobile phase. The best separation was observed at volume ratio of 78:20:2 (water:acetonitrile:acetic acid) at elevated temperature on the Zorbax SB-Phenyl column. The wavelength of UV detector was set at 254 nm. All four analytes were eluted within 8 min at 200 °C. At the end of working, it was observed that the retention times of all four analytes decreased with increasing temperature and was stated that the temperature was an effective parameter for chromatographic separation. Furthermore, the relationship between retention factor and separation temperature was examined using Van’t Hoff plots and the results demonstrated with correlation coefficient greater than 0.91 on Zorbax SB Phenyl column. Consequently, the proposed HTLC method for separation and analysis of SSRIs may be used as a green alternative technique.