Overview on liquid chromatography and its greener chemistry application

HPLC is a separation technique where analytes in a multicomponent mixture are separated due to the difference in their af inities between liquid mobile phase and solid stationary phase [1]. In HPLC, the liquid mobile phase is forced by pump system through the pores of the stationary phase into a reusable column. The irst separation in chromatography was attained by the Russian botanist, Mikhail Tswett, who separated plant pigments using calcium carbonate ine particles column. A.J.P. Martin & R.L.M. Synge won noble prize in 1952 for their contributions in the ield of chromatographic separation. Since then and due to the magical separation power and wide applications of liquid chromatography, it became the most practiced and evolved means of analytical separation. HPLC consists of a pump that forces the liquid mobile phase under high pressure through column containing stationary phase. Samples are injected at the inlet of the column then the eluents are detected and using different types of detectors and chromatogram is produced. For multiple accurate sample loading (n = 100 or more), the apparatus of autosampler is required for high throughput HPLC. Along the years, lots of improvements have been done to overcome the different disadvantages that face the use of HPLC. Among these drawbacks are the low resolution power, long separation time, high back pressure and the large volume consumption of mobile phase. Being the heart and the main core for separation, column and column packing materials were the main focus for such improvements. Factors affecting HPLC separation: In order to understand how developments in HPLC were achieved, we have to understand irst the factors that affect separation. Table 1 describes the relation between independent parameters of column length, particles size, column temperature and mobile phase low rate with the dependent parameters of analysis time, column back pressure and column ef iciency.