Various chemometric approaches, including four discriminant models (ELM, TLBO–ELM, KELM, and TLBO–KELM), were used to detect shrimp freshness based on near-infrared hyperspectral imaging.
A look at how the spectral properties single-phase green emission phosphor make it suitable for near-UV light-emitting diode (NUV-LED) applications.
When explosives are encountered on the battlefield, the use of portable GC–MS is valuable for the detection and confirmatory identification of pre- and post-detonation threats. In addition, this technique provides information about the source of explosives based on the detection and identification of trace-level chemicals in the sample. The data presented here confirm this capability.
In X-ray fluorescence (XRF) analysis, physical traceability chains are used to quantify the absolute elemental content in a sample. The physical traceability chain relies on absolute knowledge of the X-ray spectral distribution used for the excitation of the instrument and is currently used at synchrotron radiation facilities. Here, we discuss the transfer of the physical traceability chain to laboratory-based X-ray sources, which are often polychromatic, with the view to generate wider application of quantitative XRF analysis.
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 short overview, we consider cases for diffuse reflection spectroscopy and introduce the Kubelka-Munk diffuse reflectance formula. We conclude by comparing diffuse transmittance, diffuse reflectance, logarithmic transforms of both, and the Kubelka-Munk transform for mid-infrared spectroscopy of the same sample.
A complex fluorescence method utilizing the Sn(II)-salicylfluorescein (SAF)-cetyltrimethylammonium bromide (CTMAB) system demonstrated effective detection of Sn(II) with a linear relationship between its concentration and fluorescence intensity, along with successful application in various sample matrices with high recovery rates.
The possible energy transfer modes between Yb3+ and Tm3+ ions were analyzed.
FPGA-based, software-defined equipment can help labs customize system applications and save on costly resources.
Portable X-ray fluorescence was used to analyze the archaeological remains of an Underground Railroad station to gain a clearer understanding of the construction phases it underwent during the 19th century.
In combination with attenuated total reflectance (ATR), Fourier transform infrared (FT-IR) spectroscopy can be used to classify different moss species.
The advantages of machine-learning methods have been widely explored in Raman spectroscopy analysis. In this study, a lightweight network model for mineral analysis based on Raman spectral feature visualization is proposed. The model, called the fire module convolutional neural network (FMCNN), was based on a convolutional neural network, and a fire-module was introduced to increase the width of the network, while also ensuring fewer trainable parameters in the network and reducing the model’s computational complexity. The visualization process is based on a deconvolution network, which maps the features of the middle layer back to the feature space. While fully exploring the features of the Raman spectral data, it also transparently displays the neural network feature extraction results. Experiments show that the classification accuracy of the model reaches 0.988. This method can accurately classify Raman spectra of minerals with less reliance on human participation. Combined with the analysis of the results of feature visualization, our method has high reliability and good application prospects in mineral classification.
Analysis of 66 pesticides and 5 mycotoxins regulated by the State of California in cannabis tinctures were analyzed using LC–MS/MS with an ESI source, and LC–MS/MS with an APCI source. A simple, fast, and cheap acetonitrile solvent extraction method was used for sample preparation for good recovery and high throughput, and internal standards were used to compensate for ion suppression effects from the hydrophobic matrix.
In this paper, a system based on laser induced breakdown spectroscopy (LIBS) and back propagation (BP) method was developed for the composition and traceability analysis of crop burning smoke.
An increasing number of antibiotic residue problems in food have emerged around the world. We examine how SERS is used to identify antibiotic residues in chicken, focusing on doxycycline hydrochloride and tylosin.
Raman spectroscopy tracks hydrogen blending in gas turbines accurately and reliably, outperforming mass spectrometry with 100% uptime and easy adaptation for new fuels.
Fungal infections and mycotoxin contamination in food products pose a major threat to the world population. Mycotoxins contaminate approximately 25% of the world’s food products and cause severe health problems through the utilization of affected food products. The major mycotoxins in different foods are aflatoxins, ochratoxins, fumonisins, zearalenone, trichothecenes, and deoxynivalenol. Today, various conventional and nondestructive techniques are available for the detection of mycotoxins across multiple food products. Conventional methods are time-consuming, require chemical reagents, and include many laborious steps. Therefore, nondestructive techniques like near-infrared (NIR) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, hyperspectral imaging, and the electronic nose are a priority for online detection of fungal and mycotoxin problems in different food products. In this article, we discuss recent improvements and utilization of different nondestructive techniques for the early detection of fungal and mycotoxin infections in various food products.
A simple colorimetric and fluorescent dual-channel chemosensor was designed and synthesized to identify Hg2+ in an aqueous solution with demonstrated high selectivity and sensitivity.
This study examines whether the computed spectrum can be used to accurately identify amino acids, by comparing the computer spectrum to the measured spectrum of a biological sample.
Webinar Date/Time: Wed, Nov 20, 2024 2:00 PM EST
In this article, it is explored whether THz-TDS combined with LS-SVM can be used to effectively identify the authenticity of Panax notoginseng, a traditional Chinese medicine.
In this article, it is explored whether THz-TDS combined with LS-SVM can be used to effectively identify the authenticity of Panax notoginseng, a traditional Chinese medicine.
Analysts using fluorescence emission and fluorescence excitation spectroscopy may encounter several common problems in their measurements. This tutorial, the first of a three-part series, provides a procedure to help avoid them.
This application note demonstrates the performance of the Oxigraf Safety Monitor to measure the concentration of oxygen molecules in gas samples at a helium laboratory.
An inexpensive fiberoptic-based formaldehyde field sensor is described for monitoring low-levels of formaldehyde, a widespread indoor air pollutant, based on the principle of evanescent wave absorption of light. Sensor prototypes following that principle are being tested in two plywood board production plants.
A simple colorimetric and fluorescent dual-channel chemosensor was designed and synthesized to identify Hg2+ in an aqueous solution with demonstrated high selectivity and sensitivity.
In this article, the basic principles, advantages, and limitations of different optical techniques for obtaining seed vigor estimates are introduced and reviewed, and the key technology of non-destructive optical detection of single seeds will be discussed.
Spectroscopic ellipsometry, correlated with UV-vis-NIR spectroscopy, is used to determine the optical constants of thin films, such as in GexSb40-xSe60 chalcogenide glass.
This study shows that surface-enhanced Raman spectroscopy (SERS) of serum can provide an experimental basis for diagnosing leukemia in patients.
DNA effectively removes chrysene from contaminated water through intercalation, as confirmed by various analytical methods, offering a potential novel approach for chrysene elimination in water pollution.