激光诱导荧光探测水体中溶解有机物浓度

用Nd∶YAG激光器的三倍频355 nm光作为激发光源，根据激光诱导荧光（LIF）方法激发并探测污染水体的荧光光谱.通过对荧光光谱的分析处理研究归一化荧光强度，即450 nm处水中溶解有机物（DOM）峰与405 nm处水的拉曼峰的比值，反演溶解有机物浓度.用商品腐殖酸和去离子水配置成已知浓度的溶液代替标准DOM溶液进行标定，得到回归方程.结果证明，DOM的归一化荧光强度与水体中DOM浓度有较好的线性关系，因此LIF方法是对大面积水域水质进行动态遥测的较理想方法.

Detection of Dissolved Organic Matter Concentration Using Laser-Induced Fluorescence Technique

The polluted water column is excited with the third harmonics(355 nm) of Nd∶YAG laser and fluorescence spectrum is detected by laser induced fluorescence technique. After analysed and processed the spectrum data,normalization of fluorescence intensity is obtained,which is the ratio of 450 nm value to 405 nm value. Commercial humic acid is diluted with different quantity of deionized water as water sample of known DOM concentration. The result has been shown that there is a good correlation between DOM concentration and the normalization fluorescence intensity of ultraviolet laser induced fluorescence. Therefore the LIF technique is a good method for the practical utilization of in vivo monitoring polluted water column.