Cleaning and Recycling Mobile Phase for Chromatographic Separations

This work describes an environmentally friendly method to reuse the mobile phase eluent for isocratic high-performance liquid chromatographic (HPLC) systems through the use of a charcoal-packed column. In traditional systems, used mobile phase eluent is typically discarded as waste. In an effort to decrease the amount of waste generated during HPLC analyses, a recycling system was developed where separation of analytes on a traditional C18 column was followed by a mobile phase cleanup step involving a charcoal-packed column. Three different isocratic chromatographic separations were examined (each involving different mobile phase and analyte compositions). The results demonstrate that the large amount of waste produced during conventional HPLC analysis was reduced by approximately 80% when a charcoal-packed column was employed. Furthermore, reproducibility in separation performance and quantitation was not significantly affected when the recycled mobile phase was used as opposed to the fresh mobile phase.