为了准确检测土壤中的多环芳烃, 以土壤中典型多环芳烃污染物蒽为检测对象, 研究了土壤粒径大小对其荧光特性的影响, 并提出了一种校正土壤粒径大小对多环芳烃标准曲线影响的方法。研究了蒽在土壤中的荧光特性, 指出蒽在421 nm、442 nm和470 nm处出现较强的荧光峰。接着, 制备7种不同粒径大小的蒽土壤样品, 并以土壤粒径大小为外扰, 构建了同步和异步二维相关荧光谱, 研究了蒽荧光强度和304 nm处瑞利散射光强随土壤粒径大小的变化。结果显示, 随着土壤粒径增大, 蒽荧光强度和304 nm处瑞利散射光强度都有增强。最后, 分别建立了80目和160目土壤粒径下定量分析土壤蒽浓度的标准曲线, 并通过304 nm处瑞利散射光对蒽荧光进行校正。结果表明: 该方法有效降低了土壤粒径大小对蒽标准曲线的影响。

To detect the polycyclic aromatic hydrocarbons(PAHs) in soils accurately, the typical PAH pollutants of anthracene in soils was used as research targets, and the effect of soil particle size on the fluorescence characteristics was researched. Then, a correction method was established to reduce the influence of soil particle size on the standard curve of PAH. The fluorescence characteristics of anthracene in soils were studied and three fluorescence peaks were shown at 421 nm, 442 nm and 470 nm. Seven soil samples with different particle sizes contaminated with anthracene were prepared. On the basis of the perturbation of soil particle sizes, the synchronous and asynchronous two-dimensional(2D) correlation fluorescence spectra were calculated and the variations of the fluorescence intensity of anthracene and Rayleigh scattering intensity at 304 nm with soil particle sizes were studied. It was found that the fluorescence intensity of anthracene and Rayleigh scattering intensity enhance with the increase of soil particle sizes. Finally, the standard curves were established to determine the concentration of anthracene in 80 mesh and 160 mesh soils, respectively, and the fluorescence of anthracene was corrected by the Rayleigh scattering at 304 nm. The results show that the proposed corrected method effectively reduces the effect of soil particle size on the standard curve of anthracene.