Near Infrared (NIR) Spectroscopy

This study is an important contribution to the field of machine learning-enabled NIR spectroscopy, offering researchers a systematic method for selecting representative subsamples from existing data with quality measures, diagnostic tools, and visualization techniques.

A new method for detecting adulterated milk could lead to analyzing other food products more effectively.

The United States Pharmacopeia–National Formulary (USP–NF) has contributed to ensuring the quality of dietary supplements, foods, and medicines for more than 200 years. This overview explains the use of vibrational spectroscopy techniques in meeting USP–NF requirements and how the information is organized.

The accuracy of prediction models based on spectroscopic measurements can be influenced by a variety of factors, including aging equipment. Continuous monitoring is key to managing the PAT model lifecycle and ensuring that changes over time do not negatively affect prediction model performance.

In the past 20 years, spectrometers have shrunk dramatically in size, and this shrinking has been achieved with only modest performance reductions in sampling versatility, spectral range, spectral resolution, and signal-to-noise.

A PLS model was built with optimized wavelength variables generated by a competitive adaptive reweighted sampling (CARS) algorithm, enabling the use of handheld NIR spectroscopy to rapidly detect peroxide values in oil.

A novel approach to NIR spectral sensing, using a miniaturized fully-integrated multipixel array of resonant-cavity-enhanced InGaAs photodetectors, enables sensors with a millimeter-scale footprint and wafer-scale fabrication. This multipixel sensor does not measure the full spectrum, but rather a limited number of spectral regions with limited resolution (50–100 nm).

The possible energy transfer modes between Yb3+ and Tm3+ ions were analyzed.

Spectroscopy offers a range of available techniques that can be differentiated by the use or omission of reference spectra.

A model based on similarity regularized nonnegative matrix factorization (SRNMF) can be used in space exploration and national security applications to exploit the spatial information in an image of a space target.

In this second part of this four-part series on spectroscopy instrument components, we take a closer look at optical components or subassemblies used for vibrational spectroscopy instruments.

Portable NIR spectroscopy, combined with discrimination analysis (PLS-DA), can be used to rapidly and accurately identify five very similar wood species of the Cinnamomum genus.

We propose a theoretical basis using vis-NIR spectroscopy for the development of an online nondestructive testing system for the quality of Nanguo pear fruit.

Our annual review of new products for atomic and molecular spectroscopy, including details by category and highlights of overarching trends.

Controlling methane is one of the highest-impact ways to reduce climate impacts, so its accurate measurement is essential. Spectroscopy offers valuable tools for this task.

High-performance instrumentation requires many critical components. We focus here on energy sources, lasers, and detectors.

Raw data produced by an NIR instrument undergoes some sort of processing, or transformation, to make them easier to use. In this series, we explore options for that data transformation, starting with multiple linear regression (MLR).

This study provides theoretical and technical support for implementing online detection of cement raw meal components using near-infrared (NIR) spectroscopy.

This issue is a compilation of five peer-reviewed articles on the combined application of UV-vis-NIR spectral data with advanced chemometrics.

Classification and identification of different wood species are demonstrated using a portable near-infrared spectrometer, combined with four spectral pretreatment methods and three pattern recognition methods. Additional chemometric tools were used for comprehensive evaluation of classification model accuracy and complexity.

Given that grape seed oil has shown beneficial effects for consumers, there is a interest in measuring oil quality and potential adulteration. This study demonstrates an effective near-infrared (NIR) spectroscopy method, using a series of machine learning approaches for wavelength variable selection, to rapidly discriminate grape seed oil adulteration.

Spectral reflectance is a non-destructive method that is applicable to remote sensing and may be used to measure the chlorophyll content in a crop, which indicates the photosynthetic capacity, growth cycles, and degrees of stress (such as disease, insect infestation, and heavy metal stress) on plant ecosystems. This vis-NIR spectral reflectance method measures leaf chlorophyll using a wavelet analysis algorithm approach.

Depletion of modern mineral resources due to continuous exploitation and utilization makes it economically necessary to quickly identify the locate sources of low-grade ore. Here, we propose a vis-NIR remote sensing method to determine copper content in mining areas as well as to measure the environmental impact of surface mining methods.

Ozaki was presented with the award at the ICNIRS conference, which was held online this year in Beijing.

This article covers a portion of the analytical equipment and techniques used in the production of beer across the supply chain.

Inline FT-NIR and offline terahertz Raman imaging analysis are used to characterize active pharmaceutical ingredient (API) crystallinity and to monitor different solid physical states of the API, to control process parameters of hot melt extrusion.

Traditional qualitative analysis of agricultural materials using near-infrared spectroscopy can be improved using information-based classification methods, such as projection based on principal components and the Fisher criterion (PPF).

A frequency comb is a laser source, with evenly spaced narrow lines, potentially useful for spectroscopy applications, particularly as a source or for alignment of the wavelength axis.

Plasma spray–deposited metal films are used in many industrial applications. This study shows how high resolution terahertz time-domain spectroscopy (THz-TDS) can be used to analyze and characterize such films.

A rapid vis-NIR spectroscopy method for determining soil particle size and quality.