The small volumes of the samples were injected to small hydrophobic plastic vessels (cup) by a micropipette (Biohit). The end of the PTFE capillary of the nebulizer was immersed into the bottom of the microsampling cup, then the whole volume of the liquid was completely and immediately sucked into the nebulizer providing a transient signal. The signals rose sharply, and then fast declining with some tailing could be observed due to the dilution of the aerosol at the signal end. In Fig. 2,