Dimethoate coating was obtained by evaporating staturated dimethoate solution on Ag film which was prepared by magnetron sputtering. Vibrational Spectra of dimethoate coating was studied by surface-enhanced Raman scattering ( SERS). The results showed that the failure of crystal structure makes the widening and blue shift of v(P—S) and v(P = S) modes in dimethoate coating SERS system, hydrolysis causes the intensities of 8( SPOC) and δs(C0P0C) decreasing, the adsorption of 0, N ( 0 = C—N ) and the protonated 0 on Ag film induces the increase of v ( 0 = C—N ) , v ( 0 = C), 5(N—H), v(CN), S(C—N—C), S(OPO) andv(P—0) modes. The results could be used in the studies of dimethoate solution, and its residues in plants and food samples.%通过蒸发乐果饱和水溶液在磁控溅射银膜上形成乐果涂膜,利用表面增强拉曼光谱( SERS)技术研究了乐果涂膜的分子振动特性,并与乐果固体拉曼谱进行比较.研究结果表明,乐果晶体结构长程有序性的破坏造成涂膜SERS体系中v(P-S)和v(P=S)振动峰的展宽和蓝移,水解引起乐果δ(SPOC)和δs(COPOC)振动模式强度降低,O=C-N键中的O原子和N原子以及水解质子化的O在银表面吸附造成v(O=C-N)、v(O=C)、δ(N—H)、v(CN)、δ(C—N—C)、δ(OPO)和v(P-O)等振动模式显著增强.这为利用SERS技术研究乐果溶液以及乐果在植物体、食品中的残留提供了实验和理论依据.
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