To detect the nonvolatile solute (Residue After Evaporation: RAE) concentrations in variousliquids (i.e., 30% hydrogenperoxide, 9.4% ammonia solution. Isopropyl alcohol and methanol), a method consisting of liquid atomization, evaporation, diffusional deposition and condensation nucleus counting was applied and examined. From the measurements of size distribution of droplets atomized in air and deposition rate as a function of particle diameter in the flow system, the relationships (correlation curves) between the number concentration of residue particles after diffusional deposition and solute concentration were obtained. These correlation curves were used to accurately measure the RAE levels of several commercially available liquids of different grade. The measured impurity (RAE) concentrations were found to be ober ppm order, and were much higher than those of ultrapure water.