Jove
Visualize
联系我们
JoVE
x logofacebook logolinkedin logoyoutube logo
关于 JoVE
概览领导团队博客JoVE 帮助中心
作者
出版流程编辑委员会范围与政策同行评审常见问题投稿
图书馆员
用户评价订阅访问资源图书馆顾问委员会常见问题
研究
JoVE JournalMethods CollectionsJoVE Encyclopedia of Experiments存档
教育
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab Manual教师资源中心教师网站
使用条款与条件
隐私政策
政策

相关概念视频

Chemical Shift: Internal References and Solvent Effects01:17

Chemical Shift: Internal References and Solvent Effects

1.2K
In an NMR sample, precise measurement of the absolute absorption frequencies of nuclei is difficult. A standard internal reference compound is added, and the frequency difference between the reference signal and sample signals is measured.
The internal reference compound generally used in NMR spectroscopy is tetramethylsilane (TMS). TMS is preferred because it is chemically inert, soluble in NMR solvents, and easily removable. Also, the highly shielded methyl protons in TMS yield an intense...
1.2K
Applications Of NMR In Biology01:25

Applications Of NMR In Biology

4.4K
Nuclear magnetic resonance (NMR) spectroscopy is a very valuable analytical technique for researchers. It has been used for more than 50 years as an analytical tool. F. Bloch and E. Purcell formulated NMR in 1946 and won the 1952 Nobel Prize in Physics  for their work. Biological macromolecules such as proteins, nucleic acids, lipids, and organic molecules including pharmaceutical compounds, can be studied using this versatile tool that exploits the magnetic properties of certain nuclei.
4.4K
¹H NMR of Labile Protons: Deuterium (²H) Substitution00:48

¹H NMR of Labile Protons: Deuterium (²H) Substitution

1.3K
This lesson illustrates the role of deuterium substitution in simplifying the NMR spectrum of compounds comprising labile protons. One method employed is the use of deuterium. Amongst the three isotopes of hydrogen, deuterium (2H) has a nucleus composed of one proton and one neutron. When the D2O solvent is added to a pure dry ethanol solution, its labile proton is substituted with deuterium.
1.3K
NMR Spectroscopy Of Amines01:19

NMR Spectroscopy Of Amines

10.8K
In proton NMR spectroscopy, primary amines and secondary amines showcase their N–H protons as a broad signal in the chemical shift range between δ 0.5 and 5 ppm. The exact position in this range depends on several factors, including sample concentration, hydrogen bonding, and the type of solvent used. Since amine protons undergo fast proton exchange in solution, the protons are labile and therefore do not participate in any splitting with adjacent protons. Thus, the observed peak is...
10.8K
Two-Dimensional (2D) NMR: Overview01:12

Two-Dimensional (2D) NMR: Overview

1.4K
The 1D NMR spectrum of large and complex molecules like natural products has complicated splitting patterns and overlapping signals, which can be easily interpreted using 2-dimensional (2D) NMR. Unlike 1D NMR, 2D NMR has two frequency axes that provide the coupling information between the nucleus A and nucleus B in a molecule. The process from which 2D spectra are obtained has four steps.
The first step is the preparation period, during which nucleus A is excited with a radiofrequency pulse....
1.4K
2D NMR: Overview of Heteronuclear Correlation Techniques01:18

2D NMR: Overview of Heteronuclear Correlation Techniques

738
Heteronuclear correlation spectroscopy is an analytical technique that investigates the coupling between different types of nuclei, often a proton and an X-nucleus, such as carbon-13 or nitrogen-15. This method is commonly used in nuclear magnetic resonance (NMR) spectroscopy to gain insights into complex chemical compounds' structural and compositional aspects. A typical heteronuclear correlation spectrum displays X-nucleus chemical shifts on one axis and a proton spectrum on the other...
738

您也可能阅读

相关文章

通过共同作者、期刊和引用图与本文相关的文章。

排序
Same author

Evaluating machine learning algorithms to predict lameness in dairy cattle.

PloS one·2024
Same author

Portable in situ temperature-dependent spectroscopy on a low-cost microfluidic platform integrated with a battery-powered thermofoil heater.

View (Beijing, China)·2023
Same author

Microfluidic platforms integrated with nano-sensors for point-of-care bioanalysis.

Trends in analytical chemistry : TRAC·2023
Same author

A microfluidic fully paper-based analytical device integrated with loop-mediated isothermal amplification and nano-biosensors for rapid, sensitive, and specific quantitative detection of infectious diseases.

Lab on a chip·2022
Same author

Ultrasensitive detection of acephate based on carbon quantum dot-mediated fluorescence inner filter effects.

The Analyst·2022
Same author

Immunotherapy discovery on tumor organoid-on-a-chip platforms that recapitulate the tumor microenvironment.

Advanced drug delivery reviews·2022

相关实验视频

Updated: Jan 11, 2026

Single-throughput Complementary High-resolution Analytical Techniques for Characterizing Complex Natural Organic Matter Mixtures
09:38

Single-throughput Complementary High-resolution Analytical Techniques for Characterizing Complex Natural Organic Matter Mixtures

Published on: January 7, 2019

9.1K

低成本的NIR光谱与NMR光谱用于液体便的表征.

Mehdi Eslamifar1, Hamed Tavakoli2, Eiko Thiessen1

  • 1Institute of Agricultural Engineering, Max-Eyth-Straße 6, Kiel University, 24118 Kiel, Germany.

Sensors (Basel, Switzerland)
|November 13, 2025
PubMed
概括

近红外光谱 (NIRS) 显示了现场液体肥分析的潜力,准确预测干物质 (DM). 核磁共振 (NMR) 谱学为化学性质提供了卓越的实验室验证,例如总 (TN) 和 (TP).

关键词:
特性选择方法 特性选择方法液体便是一种液体便.机器学习是机器学习.接近红外光谱学近红外光谱学核磁共振是一种核磁共振.泥泥是一种泥.两个和三个频段的指数.

更多相关视频

Assessing Hepatic Metabolic Changes During Progressive Colonization of Germ-free Mouse by 1H NMR Spectroscopy
07:54

Assessing Hepatic Metabolic Changes During Progressive Colonization of Germ-free Mouse by 1H NMR Spectroscopy

Published on: December 15, 2011

13.4K
Identification and Quantification of Deranged Metabolites in Critically Ill Patients Using NMR-Based Metabolomics
11:02

Identification and Quantification of Deranged Metabolites in Critically Ill Patients Using NMR-Based Metabolomics

Published on: November 29, 2024

1.0K

相关实验视频

Last Updated: Jan 11, 2026

Single-throughput Complementary High-resolution Analytical Techniques for Characterizing Complex Natural Organic Matter Mixtures
09:38

Single-throughput Complementary High-resolution Analytical Techniques for Characterizing Complex Natural Organic Matter Mixtures

Published on: January 7, 2019

9.1K
Assessing Hepatic Metabolic Changes During Progressive Colonization of Germ-free Mouse by 1H NMR Spectroscopy
07:54

Assessing Hepatic Metabolic Changes During Progressive Colonization of Germ-free Mouse by 1H NMR Spectroscopy

Published on: December 15, 2011

13.4K
Identification and Quantification of Deranged Metabolites in Critically Ill Patients Using NMR-Based Metabolomics
11:02

Identification and Quantification of Deranged Metabolites in Critically Ill Patients Using NMR-Based Metabolomics

Published on: November 29, 2024

1.0K

科学领域:

  • 农业科学 农业科学
  • 分析化学 分析化学
  • 频谱学是一种光谱学.

背景情况:

  • 对于有效的农业营养管理来说,精确地描述液体肥料特性 (DM,TN,NH4-N,TP) 是至关重要的.
  • 传统的实验室方法可能是耗时且昂贵的现场分析.

研究的目的:

  • 调查近红外光谱学 (NIRS) 在预测液体肥料特性方面的潜力.
  • 为了比较NIRS的预测精度与核磁共振 (NMR) 光谱.
  • 评估先进的光谱预处理和机器学习技术对NIRS性能的影响.

主要方法:

  • 51个液体便样本使用实验室方法分析了参考特性.
  • 样品使用NIRS (941-1671 nm) 和NMR光谱扫描.
  • NIRS数据经过预处理,包括两段和三段索引转换和特征选择.
  • 部分最小平方回归 (PLSR) 和LASSO回归被用来开发校准模型.

主要成果:

  • 通过使用队列调整模型,NIRS证明了干物质 (DM) 的相当准确的预测 (R2 = 0.78,RPD = 2.15) .
  • 核磁共振光谱学为化学性质提供了更高的精度:TN (R2 = 0.89,RPD = 1.74),NH4-N (R2 = 0.97,RPD = 5.70) 和TP (R2 = 0.95,RPD = 2.64).这些化学性质的精度是:TN (R2 = 0.89,RPD = 1.74),NH4-N (R2 = 0.97,RPD = 5.70) 和TP (R2 = 0.95,RPD = 2.64).
  • 两带和三带指数显著改善了NIRS的表现,DM的R2增加了34%,TN的R2增加了57%,NH4-N的R2增加了25%,TP的R2增加了33%.
  • 特征选择有效地减少了光谱维度,而不会影响预测准确度.

结论:

  • 作为一个便携式工具,NIRS显示出有前途的潜力,用于现场描述液体,特别是干物.
  • 核磁共振光谱仍然是化学肥料特性准确实验室验证的基准.
  • 将NIRS与先进的预处理技术相结合,提高了其在营养管理应用中的实用性.