One key limitation is that liquid chromatography requires large quantities of costly organic solvents, which raises the overall cost for carrying out the experiment. Moreover, while running existing HPLC methods may be relatively straightforward, troubleshooting issues or developing new methods can be difficult. These issues arise from the wide range of components involved in HPLC systems, including different modules, mobile phases, and columns. A third limitation is that coelution may occur. This makes it hard to pinpoint exactly which component of a mixture has eluted at a given point in the chromatogram.