Abstract: In order to explore the transformation behavior of entering of silver nanoparticles (AgNPs),which can be used as a cosmetic additive,into underground-water environment,instrumental analysis including determination of particle size,zeta potential and light absorbance as well as SEM image and EDX spectrum was adopted for investigation of polyvinylpyrrolidone coated AgNPs (PVP-AgNPs) transformation process entering into the underground-water system in an area nearby Shenyang city.The experimental results showed that after the addition of PVP-AgNPs into the underground-water samples,its particle size changes obviously,and zeta potential value locates between -12 and -4 mV;it indicates that the PVP-AgNPs is in a rapid coagulation state.The light absorbance remains unchanged,but the absorption peak decreases continuously,such phenomenon indicates that the concentration of PVP-AgNPs decreases gradually.The SEM images and EDX spectra indicate that addition of PVP-AgNPs into the underground-water will cause coagulation sedimentation and this process can be combined with other ions to form co-precipitation.In addition,in the case of highly dissolved oxygen state and pH<7,PVP-AgNPs will dissolve and release silver ions first,and result in the decrease of PVP-AgNPs settling speed.

Key words: cosmetic additive, AgNPs, underground-water, transformation