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51.
利用碱性过硫酸钾消解紫外分光光度法,探讨了消解时间和消解温度对空白吸光值的影响,认为增加消解时间可以降低空白吸光值,而提高消解温度对空白吸光值的影响不大;对于某些样品中总氮含量低于氨氮含量的现象,将碱性过硫酸钾装入小试管,再放入装有水样的比色管中,虽然能够减少氨气形式逸出的氮含量,但回收率较低;连续流动和流动注射-盐酸萘乙二胺分光光度法,在以后的修订中应增加过硫酸钾含氮量以及镉柱还原能力大小的界定. 相似文献
52.
紫外分光光度法直接测定水中酚 总被引:1,自引:0,他引:1
阿曼古丽·阿不都热合曼 《干旱环境监测》2001,15(4):243-244,250
通过实验证明,用紫外分光光度法测定水中挥发酚,方法简便、精密度和准确度较好,适用于地表水、地下水和废水中挥发酚的测定,结果令人满意。 相似文献
53.
金芳 《环境监测管理与技术》2000,12(1):31-32
精选了一种新油标。采用这种油标,可使紫外分光光度法测地表水中石油类的令人满意,省工省时。 相似文献
54.
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56.
Morris I. Schnitzer Carlos M. Monreal Glenn A. Facey Peter B. Fransham 《Journal of environmental science and health. Part. B》2013,48(1):71-77
Fast pyrolysis of chicken manure produced two biooils (Fractions I and II) and a residual char. All four materials were analyzed by chemical methods, 13C and 1H Nuclear Magnetic Resonance Spectrometry (13C and 1H NMR), and Fourier Transform Infrared Spectrosphotometry (FTIR). The char showed the highest C content and the highest aromaticity. Of the two biooils Fraction II was higher in C, yield and calorific value but lower in N than Fraction I. The S and ash content of the two biooil fractions were low. The Cross Polarization Magic Angle Spinning (CP-MAS) 13C NMR spectrum of the initial chicken manure showed it to be rich in cellulose, which was a major component of sawdust used as bedding material. Nuclear Magnetic Resonance (NMR) spectra of the two biooils indicated that Fraction I was less aromatic than Fraction II. Among the aromatics in the two biooils, we were able to tentatively identify N-heterocyclics like indoles, pyridines, and pyrazines. FTIR spectra were generally in agreement with the NMR data. FTIR spectra of both biooils showed the presence of both primary and secondary amides and primary amines as well as N-heterocyclics such as pyridines, quinolines, and pyrimidines. The FTIR spectrum of the char resembled that of the initial chicken manure except that the concentration of carbohydrates was lower. 相似文献
57.
Plaza C Xing B Fernández JM Senesi N Polo A 《Environmental pollution (Barking, Essex : 1987)》2009,157(1):257-263
Binding of two model polycyclic aromatic hydrocarbons (PAHs), phenanthrene and pyrene, by humic acids (HAs) isolated from an organic substrate at different stages of composting and a soil was investigated using a batch fluorescence quenching method and the modified Freundlich model. With respect to soil HA, the organic substrate HA fractions were characterized by larger binding affinities for both phenanthrene and pyrene. Further, isotherm deviation from linearity was larger for soil HA than for organic substrate HAs, indicating a larger heterogeneity of binding sites in the former. The composting process decreased the binding affinity and increased the heterogeneity of binding sites of HAs. The changes undergone by the HA fraction during composting may be expected to contribute to facilitate microbial accessibility to PAHs. The results obtained also suggest that bioremediation of PAH-contaminated soils with matured compost, rather than with fresh organic amendments, may result in faster and more effective cleanup. 相似文献
58.
DDTC—TX—100胶束增溶直接光度法测定水中低含量铜 总被引:1,自引:0,他引:1
TritonX100对DDTC(二乙基二硫代氨基甲酸钠)与铜反应生成的络合物Cu(DDTC)2有增溶增敏作用,建立了低含量铜直接光度测定法。操作简便快速,选择性、精密度和回收率均较好,相对标准偏差为08%~43%,回收率为96%~106%,摩尔吸光系数ε=64×103L/(mol·cm 相似文献
59.
Romero-Ruiz A Alhama J Blasco J Gómez-Ariza JL López-Barea J 《Environmental pollution (Barking, Essex : 1987)》2008,156(3):1340-1347
Metallothionein (MT) and other biomarker levels were measured in Scrobicularia plana clams to assess pollution of the Guadalquivir Estuary possibly affected by metals released from Aznalcóllar pyrite mine in 1998. After optimizing reagent concentrations for monobromobimane derivatization, MT levels were quantified by reversed-phase high-performance liquid chromatography coupled to fluorescence detection (RP-HPLC-FD) in heated or unheated digestive gland extracts and compared to those obtained by differential pulse polarography (DPP). MT content assayed by RP-HPLC-FD in unheated samples was higher than that obtained by DPP and correlated better with metals and anti-oxidant activities. MT assay by RP-HPLC-FD in unheated extracts would be preferable for assessing metal pollution, due to its greater sensitivity and specificity. In addition to MT induction, glyoxalase II inhibition was well correlated with metal contents. Our results suggest that metals at the estuary do not originate from Aznalcóllar spill, but from those carried along by the river and deposited at its concave bank. 相似文献
60.
Spectroscopic Distribution of Dissolved Organic Matter in a Dam Reservoir Impacted by Turbid Storm Runoff 总被引:1,自引:0,他引:1
Spectroscopic characteristics of dissolved organic matter (DOM) in a large dam reservoir were determined using ultraviolet
absorbance and fluorescence spectroscopy to investigate spatial distribution of DOM composition after turbid storm runoff.
Water samples were collected along a longitudinal axis of the reservoir at three to four depths after a severe storm runoff.
Vertical profiles of turbidity data showed that a turbid water layer was located at a middle depth of the entire reservoir.
The spectroscopic characteristics of DOM samples in the turbid water layer were similar to those of terrestrial DOM, as demonstrated
by the higher specific UV absorbance (SUVA) and the lower fluorescence emission intensity ratio (F
450/F
500) compared to other surrounding DOM samples in the reservoir. Synchronous fluorescence spectroscopy revealed that higher content
of humic-like DOM composition was contained in the turbid water. Fluorescence excitation–emission matrix (EEM) showed that
lower content of protein-like aromatic amino acids was present in the turbid water DOM. The highest protein-like fluorescence
was typically observed at a bottom layer of each sampling location. The bottom water DOM exhibited extremely high protein-like
florescence near the dam site. The particular observation was attributed to the low water temperature and the isolation of
the local bottom water due to the upper location of the withdrawal outlet near the dam. Our results suggest that the distribution
of DOM composition in a dam reservoir is strongly influenced by the outflow operation, such as selective withdrawal, as well
as terrestrial-origin DOM inputs from storm runoff. 相似文献