Study On Determination Of Mercaptans And Chlordimeform By Surface-enhanced Raman Spectroscopy

Raman spectroscopy is an important method of qualitative and structural analysis.Surface-enhanced Raman spectroscopy (SERS) can provide six or more magnitudeenhanced Raman signals of analytes that have been adsorbed onto specially preparedsurfaces of the substrate through the interaction between the molecular and substrate.Because of high intensity, slight effect of water interference, especially developmentof the small portable instrumentation, SERS has been an ideal method in bothqualitative and quantitative applications. As the development of substrate, SERSdevelops very fast in a wide variety of applications, such as analytical science, surfacescience and biological science. Based on the SERS，mercaptans and chlordimeformwere determined using metal nanoparticles as substrates, and the gasoline andenvironmental water were analyzed at the same time.Mercaptans in gasoline were determined by the surface-enhanced Ramanspectroscopy. The silver nanoparticles were used as substrates. Under the optimumconditions, the enhanced SERS intensities are proportional to the concentrations ofmercaptans in a certain ranges. The correlation coefficients(r) are higher than0.9972,which shows a good linear relationship between the SERS intensity and theconcentration of mercaptan. The limits of detection for1-propanethiol、2-propanethioland1-butanethiol are0.86、0.12、0.39mg/L respectively. Real samples were alsoanalyzed by this method. The recoveries were between53.29%and111.51%withRSD≤8.94%.Gold colloid was used as SERS substrates to determine chlordimeform. Theinfluence of experimental parameters were examined in order to achieve the optimum SERS signals. Under the optimum conditions, the SERS intensity is proportional tothe concentration of chlordimeform in a certain range. The corresponding correlationcoefficient of the linear equation is0.998, The limits of detection for chlordimeformis0.36μg/mL. The recoveries of the chlordimeform in real water samples arebetween68.26%and90.13%and the RSDs are between0.69%and6.15%. Theseresults show that recoveries of chlordimeform and the reproducibility are satisfactory.