Evaporation of solvent from the autosampler vial can be a significant issue for samples that are left out for several days before analysis.
The evaporation can change the concentration of analytes in solution and cause quantitative errors. For these reasons, it is important to know what factors affect evaporation. The volatility of the solvent is important, but so is the choice of autosampler cap. These factors are compared using easy to read graphs that illustrate the effect of each variable on evaporative loss. The findings can help facilitate the selection of proper vial and solvent conditions to minimize these effects.