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峡谷分层型水源水库表层沉积物溶解性有机物光谱特征 总被引：7，自引：1，他引：6
结合三维荧光光谱技术（EEMs）与紫外吸收光谱（UV-vis），并利用平行因子分析（PARAFAC）的方法，对金盆水库表层沉积物中溶解性有机质（DOM）光谱的空间分布特征及来源进行分析，并探讨沉积物DOM的荧光组分与可溶性有机氮（SON）、可溶性无机氮（SIN）之间的相关性.结果表明，金盆水库表层沉积物DOM由3类荧光组分组成，分别是类富里酸C1（235 nm，315 nm/430 nm）、类色氨酸C2（220 nm，275 nm/330 nm）和类胡敏酸C3（265 nm/520 nm），各组分荧光强度占总荧光强度百分比的平均值分别为43.15%、31.54%和25.31%.表层沉积物DOM浓度在空间上呈现从上游到主库区先减少后增加的趋势.光谱斜率S275-295、S350-400和光谱斜率比SR反映出各采样点陆源与内源占比的差异性.荧光指数、自生源指标和腐殖化指标都表明金盆水库沉积物DOM的来源具有内源与陆源双重特征.相关性分析表明，表层沉积物DOM各组分与SON和SIN均呈显著正相关，说明DOM与氮元素的迁移转化密切相关. 相似文献
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A multivariate calibration procedure based on principal component analysis is proposed.UV-vis spectraof ternary mixtures have been used to check the applicability of the procedure. 相似文献
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1IntroductionDissolvedorganicmatter (DOM)isamixtureoforganicsubstancesconsistingmainlyofhighmolecularweightpolymericcompounds (KenandLee,1 974) .Itplaysanimportantroleincarboncyclingandbiogeochemicalmobilizationoftracemetalsandorganiccompoundsintheaquaticenvi ronment (BeffleandLeppard ,1 995) .InrecentyearsmanyresearchershavepaidattentiontothesecomplexesbasedontheMWDofDOM ,sincethefateandtransportoftracechemicalsareinfluencedbyitsmolecularsize (Chiouetal.,1 986) .Themolecularweightorfrac… 相似文献
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Xiaodong MA Nawab ALI 《中国地球化学学报》2006,25(B08):267-267
Naturally occurring organic compounds are complicated materials that are hard to fractionate into individual components. Organic materials from lakes, rivers and oceans often contain biological molecules related to proteins and DNA, and have global environmental and ecological importance. In this study, we used a combination of biochemical, chromatographic and spectroscopic methods to fractionate and characterize Suwannee River fulvic acid （SRFA） to determine if it contains proteins and DNA or DNA-like materials. A stock solution of SRFA （50 mg/mL） was prepared in double distilled deionized water. An initial biochemical analysis indicated that SRFA contained approximately 2% protein by weight, as determined by Bradford method using bovine serum albumin as standard. In order to determine the presence of DNA-like materials, a portion of the SRFA sample was extracted for DNA using chloroform/phenol extraction and ethanol precipitation method. When ethanol precipitated fraction was separated by agarose gel electrophoresis along with known DNA markers, a diffused ehthidium bromide staining was observed throughout the lane containing SRFA sample with a strong staining observed at the dye front, suggesting the presence of DNA or ＂DNA-like＂ molecules of various sizes in SRFA. To further fractionate, the DNA-like material on the gel was cut into seven fractions, each of which was extracted into aqueous phase. These fractions, along with the fractions obtained similarly from the original SRFA and an interface material during chloroform/ phenol extraction, were analyzed using UV-vis and fluorescence spectrometers, and LC/UV/MS. Comparisons of the absorption, fluorescence and mass spectra of various fractions revealed significant differences in their spectral properties. The DNA extracted materials showed stronger absorption in the DNA range of -260 nm than the original SRFA and interface material. 相似文献
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Faye ZHAO Xiaodong MA 《中国地球化学学报》2006,25(B08):279-279
Dissolved organic matter （DOM）, a mixture of numerous organic compounds of 30 to 300000 D, exists in all natural water resources including rivers, lakes and oceans, and plays a very important role in global carbon cycle and ecology. The DOM molecules absorb UV light strongly in short wavelengths and prevent microorganisms from being damaged by solar UV irradiation. Meanwhile, the large DOM molecules are then photodegraded into inorganic carbon and smaller organic molecules which are easier for bacterioplankton to digest. The Arkansas River is one of the largest rivers in the US, and a major input of organic materials to the Mississippi River and Gulf of Mexico. However, the photochemical properties of the DOM in the river water have not been investigated. To study this photodegradation process of the Arkansas River, water samples from the river were collected, filtered, sealed into quartz flasks, and exposed to sunlight for up to 15 hours. Some samples were retrieved from the flasks at certain time intervals. The intensity of the sunlight was measured during the exposure process at 30 min to 1 hr intervals. UV-vis absorption, fluorescence emission, 3D fluorescence spectra and DOM concentrations were determined for all retrieved samples. It was found that the total DOM concentration decreased while the dissolved inorganic carbon （DIC） concentration increased in the samples. UV absorption and fluorescence intensity of DOM decreased exponentially. The disappearance rate of UV absorption varied with wavelength. The loss of integral fluorescence was about 2.6 times that of the UV absorption at the excitation wavelength. In addition, the quantum yields also decreased, and the peak position of 3D fluorescence scan shifted to shorter wavelength. 相似文献
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