稳定水同位素的开放路径测量使用中红外双光谱学
Daniel I Herman1,2, Griffin Mead1, Fabrizio R Giorgetta1,2
1Spectrum Technology and Research Division, National Institute of Standards and Technology, Boulder, Colorado 80305, United States of America.
概括
我们开发了一种开放式双光谱系统,用于精确的水同位素测量. 这种先进的系统显示出高精度,可与已建立的网络相提并论,从而实现了更好的生态监测.
科学领域:
- 环境科学 环境科学
- 频谱学是一种光谱学.
- 大气化学 大气化学
背景情况:
- 精确测量水同位素 (H216O和HD16O) 对于了解水文循环和气候至关重要.
- 现有的监测网络可能缺乏详细的水运研究的精度和空间覆盖.
研究的目的:
- 为准确的水同位素测量提供和验证一个开放路径的中红外双光谱 (DCS) 系统.
- 将DCS系统的性能与已建立的生态监测网络 (NEON) 进行比较.
- 评估DCS在加强生态监测网络方面的潜力.
主要方法:
- 在一个偏远的农村试验场部署一个开放路径的中红外双光谱 (DCS) 系统.
- 长期 (3.75个月) 数据收集,正常运行时间为60%.
- 从DCS衍生的三角 (δD) 值与来自国家生态观测站网络 (NEON) 同位素点传感器网络的数据进行比较.
主要成果:
- 在H216O和HD16O (δD) 的正常化比率上,DCS系统实现了<2‰的精度.
- DCS和NEON δD值之间的平均差异为<2‰,标准偏差为18‰,显示出高精度.
- 尽管大气条件不同,但在DCS和NEON地点之间观察到相关的日间形状和季节性趋势.
结论:
- 开放式DCS提供了精确和准确的水同位素测量,适合不同的大气条件.
- DCS的高准确性和精度支持其融入更密集的生态监测网络.
- DCS技术为了解区域和综合规模的水运提供了新的能力.
相关概念视频
Atomic Absorption Spectroscopy: Instrumentation
755
An atomic absorption spectrophotometer (AAS) comprises several components: a radiation source, an atomizer, a monochromator, and a detector. The radiation source can be a hollow-cathode lamp (HCL) or an electrodeless-discharge lamp (EDL), both of which provide a narrow emission line of the required wavelength. However, some instruments use continuum sources and high-resolution monochromators to achieve a narrow range of radiation.
The atomizer used in AAS can be either a flame atomizer or an...
The atomizer used in AAS can be either a flame atomizer or an...
755
Atomic Absorption Spectroscopy: Lab
459
For AAS measurements, samples must be introduced as clear solutions, often requiring extensive preliminary treatment to dissolve materials like soils, animal tissues, and minerals. Common methods for sample preparation include treatment with hot mineral acids, wet ashing, combustion in closed containers, high-temperature ashing, or fusion with reagents.
Solutions containing organic solvents, such as low-molecular-mass alcohols, esters, or ketones, enhance absorbances by increasing...
Solutions containing organic solvents, such as low-molecular-mass alcohols, esters, or ketones, enhance absorbances by increasing...
459
Applications of IR Spectroscopy: Overview
756
The non-destructive nature and ability to provide valuable chemical information make IR spectroscopy a versatile technique with broad applications in various scientific and industrial fields. IR spectroscopy is commonly used to identify and characterize organic and inorganic compounds. It provides information about the functional groups present in a molecule and the bonding between atoms. This helps in the structural elucidation of compounds during organic synthesis, pharmaceutical research,...
756
Atomic Absorption Spectroscopy: Atomization Methods
533
Atomic Absorption Spectroscopy (AAS) atomizes samples through flame atomization or electrothermal atomization. Flame atomization typically involves a nebulizer and spray chamber assembly to combine the sample with a fuel–oxidant mixture, creating a fine aerosol mist that enters a burner. Typically, the fuel and oxidant are combined in an approximately stoichiometric ratio. However, for atoms that are easily oxidized, a fuel-rich mixture may be more advantageous. Only about 5% of the...
533
UV–Vis Spectrometers
1.4K
The absorbance of UV and visible (UV–visible) radiations is measured using a UV–visible spectrophotometer. Deuterium lamps, which emit UV radiation, and tungsten lamps, which produce radiation in the visible region, are used as light sources in UV–visible spectrophotometers. A monochromator or prism is used for diffraction grating, i.e., to split the incoming radiation into different wavelengths. A system of slits is used to focus the desired wavelength on the sample cell.
1.4K
UV–Vis Spectroscopy of Conjugated Systems
7.1K
Organic compounds with conjugated double bonds show strong absorption features in the UV–visible region of the electromagnetic spectrum attributed to π → π* electronic excitations. Generally, a UV–vis absorption spectrum is recorded as a plot of absorbance vs wavelength. The wavelength of maximum absorbance, which manifests as a peak in the absorption spectrum, is denoted as λmax.
One of the factors influencing λmax is the extent...
One of the factors influencing λmax is the extent...
7.1K


