Appearance of gas bubbles coming out from the spots of some surfactants on silica plates was examined. The plates were dipped into water after chromatograms had been developed. Experimental results had shown that only anionic surfactants gave white spots with gas bubbles (rare and slightly some nonionic surfactants, and never cationics). Therefore, this occurrence can be used for detection (and identification) of anionic surfactants, and for determination of polarity of surfactants.