胶州湾围隔实验中溶解有机物三维荧光特征

利用三维荧光激发发射矩阵光谱法(EEMS),测定胶州湾围隔实验中不同营养盐条件下产生的溶解有机物的三维荧光特性.结果显示,浮游植物可产生类蛋白和类腐殖质荧光,类蛋白荧光峰由类酪氨酸(tyrosine-like)荧光峰和类色氨酸(tryptophan-like)荧光峰组成,主要位置为Ex_max/Em_max=270 nm/290～310 nm,Ex_max/Em_max=270～290 nm/320～350 nm的荧光峰强度比较弱;在Ex_max/Em_max=250～260 nm/380～480 nm(A峰)、Ex_max/Em_max=310～320 nm/380～420 nm(C峰)和Ex_max/Em_max=330～350 nm/420～480 nm(M峰)位置均出现零散的类腐殖质荧光峰,其中以A峰为主.类酪氨酸荧光强度明显高于类腐殖质荧光强度.浮游植物量降低时,类酪氨酸荧光强度与叶绿素a浓度呈明显的负相关.硅藻和甲藻产生的类酪氨酸和类色氨酸荧光强度之间具有较好的相关性,两者来源相似, 并且甲藻与硅藻相比能够产生更多的类蛋白荧光物质.不同环境下类腐殖质混合物的组分比例不同,甲藻生长环境下相对于硅藻具有较低的A/C比值.

Three-dimensional fluorescence characteristic of dissolved organic matter in marine mesocosm experiment in Jiaozhou Bay, China

The three-dimensional fluorescence of dissolved organic matter in the mesocosm with different nutrients enrichment experiments in Jiaozhou Bay was determined by using excitation-emission matrix spectrum. The result indicates that phytoplankton can produce protein-like and humic-like fluorescent matter. The protein-like fluorescence is composed of tyrosine-like fluorescence and tryptophan-like fluorescence. The main position of protein-like fluorescent peak is Ex(max)/Em(max) = 270 nm/290 - 310 nm. The fluorescent intensity of the peak located in Ex(max/ Em(max) = 270 - 290 nm/320 - 350 nm is less. The centers of humic-like peaks disperse at Ex(max)/Em(max) = 250 - 260 nm/380 - 480 nm (Peak A), Ex(max)/Em(max) = 310 - 320 nm/380 - 420 nm(Peak C) and Ex(max)/Em(max) = 330 - 350 nm/420 - 480 nm(Peak M) in which peak A is the main peak. The fluorescent intensity of tyrosine-like matter is stronger than the intensity of humic-like matter. When the amount of phytoplankton decreased, the fluorescent intensity of tyrosine-like matter has negative relativity with the chlorophyll-a concentration. Tyrosine-like matter and tryptophan-like matter have similar origin. Dinoflagellate can produce more protein-like fluorescent matter than diatom. The composition ratios of humic-like mixture are different in different environment. And it has a small A/C value in dinoflagellate environment compared to diatom environment.