Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

IR Frequency Region: Fingerprint Region01:03

IR Frequency Region: Fingerprint Region

1.6K
IR spectra are divided into two main regions: the diagnostic region and the fingerprint region. The diagnostic region of the spectrum lies above 1500 cm−1. The absorptions resulting from single-bond vibrations of the N–H, C–H, and O–H stretch at higher wavenumbers and appear on the left side of the spectrum. The stretching absorptions of the C≡C and C≡N occur between 2100–2300 cm−1. In contrast, those arising from stretching absorptions of the...
1.6K
UV–Vis Spectroscopy: Woodward–Fieser Rules01:29

UV–Vis Spectroscopy: Woodward–Fieser Rules

27.4K
UV–Visible absorption spectra of conjugated dienes arise from the lowest energy π → π* transitions. The light-absorbing part of the molecule is called the chromophore, and the substituents directly attached to the chromophore are called auxochromes. A strong correlation exists between the absorption maxima, λmax, and the structure of a conjugated π system. The Woodward–Fieser rules predict the value of λmax for a given structure by adding the...
27.4K
IR and UV–Vis Spectroscopy of Aldehydes and Ketones01:29

IR and UV–Vis Spectroscopy of Aldehydes and Ketones

6.9K
Infrared spectroscopy, also known as vibrational spectroscopy, is mainly used to determine the types of bonds and functional groups in molecules. In aldehydes and ketones, the carbonyl (C=O) bond shows an absorption around 1710 cm-1. The C=O bond vibration of an aldehyde occurs at lower frequencies than that of a ketone. In addition to the C=O absorption in an aldehyde, the aldehydic C–H bond also gives two peaks in the 2700–2800 cm-1 range. This absorption, coupled with the...
6.9K
Attenuated Total Reflectance (ATR) Infrared Spectroscopy: Overview01:13

Attenuated Total Reflectance (ATR) Infrared Spectroscopy: Overview

919
Attenuated total reflectance (ATR) infrared spectroscopy is a powerful analytical technique used to study the composition of materials. It is widely employed in chemistry, materials science, forensic science, and other fields where sample characterization is required. ATR has several advantages over traditional transmission IR spectroscopy, including the requirement of little to no sample preparation and the ability to analyze a wide range of samples.
The ATR process begins by directing a beam...
919
IR and UV–Vis Spectroscopy of Carboxylic Acids01:28

IR and UV–Vis Spectroscopy of Carboxylic Acids

5.3K
In IR spectroscopy of carboxylic acids, the C=O bond shows a characteristic band between 1710 and 1760 cm⁻¹, and the O–H bond exhibits a broad band between 2500 and 3300 cm⁻¹.
However, the stretching absorptions for the C=O bond vary depending on the structure of carboxylic acids. The C=O bond of the free carboxylic acids shows a higher stretching frequency, 1760 cm−1, while H-bonded carboxylic acids (dimers) exhibit stretching absorptions at a lower frequency,...
5.3K
Infrared (IR) Spectroscopy: Overview01:09

Infrared (IR) Spectroscopy: Overview

4.3K
When electromagnetic radiation passes through a material, atoms or molecules transition from a lower to a higher energy state by absorbing radiation corresponding to the energy difference between the two states. The absorption of infrared (IR) radiation causes transitions between vibrational energy levels in a molecule. Therefore, IR spectroscopy is a useful analytical tool for determining the molecular structure of molecules.
Different compounds display unique properties due to their...
4.3K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Reclassification of the main impurity (-)-scopolamine hydrobromide trihydrate in scopolamine butylbromide: an integrated ICH M7 guideline assessment combining <i>in silico</i>, <i>in vitro</i>, and <i>in vivo</i> studies.

Toxicology mechanisms and methods·2026
Same author

Neohesperidin Regulates Lipid Metabolism and Ameliorates MASLD by Targeting ECHS1.

Phytotherapy research : PTR·2026
Same author

Research on dynamic monitoring of nitrogen-driven quality changes throughout the entire growth period of cucumbers based on deep learning.

Food chemistry·2026
Same author

PK/PD study of vancomycin in enterococcal infections: efficacy and safety assessment under the guidance of TDM.

Microbiology spectrum·2026
Same author

Phacoemulsification with goniosynechialysis for nanophthalmos with secondary angle-closure or secondary angle-closure glaucoma: a 20-case series and stepwise management strategy.

BMC ophthalmology·2026
Same author

Initiation and sustenance of Chinese Wushu practice: a structural equation model validation of the multi-theory model.

Frontiers in psychology·2026
Same journal

RETRACTED: Atta et al. Effect of Montmorillonite Nanogel Composite Fillers on the Protection Performance of Epoxy Coatings on Steel Pipelines. <i>Molecules</i> 2017, <i>22</i>, 905.

Molecules (Basel, Switzerland)·2026
Same journal

Correction: Chen et al. Chemical Composition of <i>Litsea pungens</i> Essential Oil and Its Potential Antioxidant and Antimicrobial Activities. <i>Molecules</i> 2023, <i>28</i>, 6835.

Molecules (Basel, Switzerland)·2026
Same journal

Correction: Ruan et al. Comparison of Extraction, Isolation, Purification, Structural Characterization and Immunomodulatory Activity of Polysaccharides from Two Species of <i>Cistanche</i>. <i>Molecules</i> 2025, <i>30</i>, 4754.

Molecules (Basel, Switzerland)·2026
Same journal

Correction: Li et al. Gastrodin Ameliorates Cognitive Dysfunction in Vascular Dementia Rats by Suppressing Ferroptosis via the Regulation of the Nrf2/Keap1-GPx4 Signaling Pathway. <i>Molecules</i> 2022, <i>27</i>, 6311.

Molecules (Basel, Switzerland)·2026
Same journal

Correction: Zueva et al. Steady-State Kinetics of Enzyme-Catalyzed Hydrolysis of Echothiophate, a P-S Bonded Organophosphorus as Monitored by Spectrofluorimetry. <i>Molecules</i> 2020, <i>25</i>, 1371.

Molecules (Basel, Switzerland)·2026
Same journal

1,4-Diazatriphenylene and Its Hetero-Fused Analogs: Synthesis and Applications.

Molecules (Basel, Switzerland)·2026
See all related articles

Related Experiment Video

Updated: Dec 3, 2025

Combining Raman Imaging and Multivariate Analysis to Visualize Lignin, Cellulose, and Hemicellulose in the Plant Cell Wall
07:51

Combining Raman Imaging and Multivariate Analysis to Visualize Lignin, Cellulose, and Hemicellulose in the Plant Cell Wall

Published on: June 10, 2017

12.2K

Authentication and Provenance of Walnut Combining Fourier Transform Mid-Infrared Spectroscopy with Machine Learning

Hongyan Zhu1, Jun-Li Xu2

  • 1College of Electronic Engineering, Guangxi Normal University, Guilin 541004, China.

Molecules (Basel, Switzerland)
|October 31, 2020
PubMed
Summary
This summary is machine-generated.

Fourier transform mid-infrared spectroscopy and machine learning accurately classify walnut origins and varieties. This rapid method offers an effective alternative to traditional, time-consuming chemical analyses for walnut authentication.

Keywords:
Fourier transform mid-infrared spectroscopygenetic algorithm-partial least squaresmachine learningsuccessive projection algorithmwalnut

More Related Videos

Author Spotlight: Advancements in X-ray CT Tool Chain for Tree Core Analysis
06:56

Author Spotlight: Advancements in X-ray CT Tool Chain for Tree Core Analysis

Published on: September 22, 2023

1.4K
O-cresol Concentration Online Measurement Based On Near Infrared Spectroscopy Via Partial Least Square Regression
06:50

O-cresol Concentration Online Measurement Based On Near Infrared Spectroscopy Via Partial Least Square Regression

Published on: November 8, 2019

6.9K

Related Experiment Videos

Last Updated: Dec 3, 2025

Combining Raman Imaging and Multivariate Analysis to Visualize Lignin, Cellulose, and Hemicellulose in the Plant Cell Wall
07:51

Combining Raman Imaging and Multivariate Analysis to Visualize Lignin, Cellulose, and Hemicellulose in the Plant Cell Wall

Published on: June 10, 2017

12.2K
Author Spotlight: Advancements in X-ray CT Tool Chain for Tree Core Analysis
06:56

Author Spotlight: Advancements in X-ray CT Tool Chain for Tree Core Analysis

Published on: September 22, 2023

1.4K
O-cresol Concentration Online Measurement Based On Near Infrared Spectroscopy Via Partial Least Square Regression
06:50

O-cresol Concentration Online Measurement Based On Near Infrared Spectroscopy Via Partial Least Square Regression

Published on: November 8, 2019

6.9K

Area of Science:

  • Agricultural Science
  • Analytical Chemistry
  • Data Science

Background:

  • Walnut nutritional value and price vary significantly by variety and origin.
  • Conventional analytical methods for walnut classification are time-consuming and labor-intensive.
  • Developing rapid, accurate methods for walnut authentication is crucial.

Purpose of the Study:

  • To apply Fourier transform mid-infrared spectroscopy (FTIR) combined with machine learning (ML) for classifying walnut varieties and origins.
  • To develop models for differentiating geographical origins, identifying varieties within the same origin, and classifying all varieties.
  • To assess the effectiveness of FTIR-MS and ML in walnut authentication.

Main Methods:

  • Utilized wavelet transform for spectral smoothing and denoising.
  • Developed three ML models using five classifiers to differentiate origins, identify varieties, and classify all 10 varieties.
  • Compared the performance of full spectral range versus optimal spectral subsets.

Main Results:

  • Variety identification within the same origin achieved 100% accuracy for some cases.
  • Geographical origin classification reached 96.97% accuracy.
  • Overall classification of 10 varieties yielded 87.88% accuracy.
  • Back propagation neural network (BPNN) outperformed other classifiers, including random forests (RF).
  • Optimal spectral subsets improved classification accuracy for certain models.

Conclusions:

  • FTIR spectroscopy coupled with ML provides an effective and rapid method for walnut authentication and provenance determination.
  • The developed models demonstrate high potential for distinguishing walnut varieties and origins.
  • BPNN shows superior performance for this classification task.