土壤湿度对多环芳烃荧光特性的影响

荧光光谱技术已被用于检测土壤中多环芳烃。但土壤湿度对多环芳烃的荧光强度产生很强的干扰，这对于荧光光谱技术的土壤多环芳烃快速实时检测技术的发展无疑是一种挑战。为了研究土壤湿度对多环芳烃荧光特性的影响，分别配置了八个不同湿度(含水量5%～40%，间隔5%)的菲土壤样品。采用美国PE公司的LS-55荧光分光光度计对不同湿度含量的菲土壤样品进行了检测，得到不同湿度含量下的一维动态荧光谱，以土壤湿度为外扰，研究了其二维相关荧光光谱特性，发现菲土在386，408和432 nm处荧光强度随着土壤中湿度的增大而增强，而333 nm处瑞利散射光强度却在减小，提出通过建立菲荧光强度、瑞利散射光强度与土壤湿度之间的关系，有可能实现土壤湿度对菲荧光强度影响的校正。同时，也研究了土壤湿度对定量分析菲浓度标准曲线的影响，指出土壤湿度极大影响着精准定量分析菲浓度标准曲线的建立。

Effect of Soil Moisture Content on the Fluorescence Characteristics of Polycyclic Aromatic Hydrocarbons

Fluorescence spectroscopy has been used to detec t polycyclic aromatic hydrocarbons (PAHs) in soil.However,the soil moisture ha s a strong interference to the fluorescence intensity of PAHs,which is a challe nge to the development of the rapid real-time detection technology of PAHs in s oil.In order to analyze the effect of soil moisture on the fluorescence charact eristics of PAHs,8 phenanthrene contaminated soil samples were prepared with di fferent moisture content (5％～40％,interval of 5％).The dynamic one-dimensional fluorescence spectra of soil samples with different moisture content were obtain ed by LS-55 fluorophotometer.Two-dimensional (2D) correlation fluorescence sp ectrum was calculated under the perturbation of soil moisture content.It was fo und that the fluorescence intensity of phenanthrene at 386,408 and 432 nm enhan ced with the increase of soil moisture content,while the Rayleigh scattering li ght intensity at 333 nm was decreased.And,it is pointed out that the effect of soil moisture on fluorescence can be corrected by establishing the relationship among fluorescence intensity,Rayleigh scattering intensity and soil moisture c ontent.Meanwhile,the effect of soil moisture on the standard curve of phenanth rene concentration was studied.It is demonstrated that the soil moisture has a great influence on the quantitation of phenanthrene.