Use only volatile mobile phases. All constituents, i.e. solvents and additives, of the mobile phase should be sufficiently volatile to allow evaporation under the conditions used.
Non-volatile solutes in the mobile phase, even at trace amounts, produce a detector signal (background current, noise, drift). Minimize their concentration.
TIP
A careful consideration in the selection of the mobile phase components will be helpful in minimizing the baseline noise and optimizing the performance during analysis.
Consider other possible sources of mobile phase and eluent contamination.
Examples: Labware, pH electrodes, columns and system components
In many cases, it is preferable to use materials dedicated for use only with volatile mobile phases.
NP solvents: NP solvents are highly soluble in the gas and might condensate in the gas exhaust tubing.