沉积物孔隙水的拉曼光谱探测及荧光时间演化特性

Temporal Fluorescence Characteristics of Sediment Pore Water Using Raman Spectroscopy Detection

为了研究孔隙水取样后的荧光时间演化特性,对柱状沉积物榨取得到的孔隙水样品进行了光谱采集。拉曼光谱分析表明,沉积物中的SO_4^(2-)浓度随深度变大而逐渐减小,这说明沉积物孔隙水中的SO_4^(2-)参与了沉积物中硫酸盐还原而被消耗;同一深度的孔隙水样品随着暴露时间的不同,采集到的拉曼光谱的荧光背景也有所差别。荧光光谱分析表明,随着孔隙水暴露时间的延长,在300~350 nm处的荧光峰的强度逐渐变大,并对荧光的形成机制进行了初步分析。

In order to investigate the temporal characteristics of its fluorescence background, spectra of the pore water squeezed from sediment core were obtained. Concentration gradient of SO4^2-, which suggests depletion of SO4^2- by sulfate reduction, was observed within the pore water using Raman spectroscopy. Besides, a notable fluorescence background difference in the Raman spectra of the pore water over different exposure duration to air was also observed. The fluorescence spectroscopy analysis of the pore water showed that the fluorescence at 300-350 nm increases gradually over time once the sediment core was recovered. Possible explanations for the results were preliminarily discussed.