Applied Spectroscopy最新文献

{"title":"Prediction of Olivine Composition Under Limited Calibration Inputs: Comparative Study of Mid-Infrared Reflection, Raman Scattering, and Laser-Induced Plasma Spectroscopies.","authors":"Sergey G Pavlov, Iris Weber, Ute Böttger, Ulrich Schade, Jörg Fritz","doi":"10.1177/00037028241305162","DOIUrl":"10.1177/00037028241305162","url":null,"abstract":"<p><p>In situ optical analytical spectroscopies offer great geochemical insights due to their capability to resolve the chemical composition of regolith surfaces of rocky celestial bodies. The use of suitable calibration targets improves the precision of mineral determination, which is of critical importance for short-living, low-mobility landers, and enables, in special cases, determination of elemental composition. We investigate the capabilities of three space-relevant optical analytical techniques used for in situ mineralogical analysis, i.e., mid-infrared reflection, Raman light scattering, and laser-induced plasma spectroscopies, to predict the chemical composition of olivine under a limited calibration input, namely using two bulk samples of natural olivine, chemically close to the end-members of the mineral group. We determine the accuracy of the forsterite numbers obtained with each technique and discuss the choice of calibration methods applicable to limited in situ calibration input, which are summarized in recommendations for space instrumentation.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"767-783"},"PeriodicalIF":2.2,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142891710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Different Measuring Backgrounds on the Classification of Multilayer Polyolefin Films Using a Near-Infrared Handheld Spectrometer.","authors":"Hana Stipanovic, Patrick Arth, Gerald Koinig, Nikolai Kuhn, Jakob Lederer, Dominik Blasenbauer, Anna-Maria Lipp, Alexia Tischberger-Aldrian","doi":"10.1177/00037028241307034","DOIUrl":"10.1177/00037028241307034","url":null,"abstract":"<p><p>The low thickness of plastic films poses a challenge when using near-infrared (NIR) spectroscopy as it affects the spectral quality and classification. This research focuses on offering a solution to the challenge of classifying multilayer plastic film materials with a focus on polyolefin multilayer plastics. It presents the importance of spectral quality on accurate classification. The aim is to demonstrate the suitability of the handheld NIR spectrometer in classifying multilayer polyolefin films and assess the impact of various measuring backgrounds (white tile, Teflon, aluminum, copper, silver, and gold) on classification accuracy in the wavelength range of 1596-2396 nm. Metallic backgrounds have been found to enhance spectral quality and classification accuracy. The classification accuracy was consistently high, ranging from 96.55% to 100%, with aluminum and gold backgrounds yielding the best results in theoretical accuracy. In experimental classification, the accuracy reached 100% when any metallic backgrounds were used. Conversely, Teflon showed a theoretically high accuracy of 96.21% but only achieved an experimental accuracy of 72.2%. These findings suggest that using metallic backgrounds can improve the spectral quality and classification of plastics with low thickness (films) and complex material composition (multilayers).</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"816-828"},"PeriodicalIF":2.2,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12053275/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142891708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advertising and Front Matter.","authors":"","doi":"10.1177/00037028251338081","DOIUrl":"https://doi.org/10.1177/00037028251338081","url":null,"abstract":"","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":"79 5","pages":"737-740"},"PeriodicalIF":2.2,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143969379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Helium Detection in Natural Gas Using Raman Spectroscopy.","authors":"Aleksandr S Tanichev, Dmitry V Petrov","doi":"10.1177/00037028241282669","DOIUrl":"10.1177/00037028241282669","url":null,"abstract":"<p><p>Raman spectroscopy has great potential for quantitative analysis of natural gas. Helium is one of the components of natural gas and has a wide range of applications. It was believed that noble gases could not be detected using this technique due to the absence of their vibrational spectra. In this study, we demonstrated an approach to extracting the content of helium from the Raman spectrum of methane and carried out test measurements for the first time. The approach is based on the determination of changes in the ν₁ band of methane caused by the influence of helium and other components. The necessary spectroscopic parameters characterizing the effect of methane (CH₄), helium (He), nitrogen (N₂), carbon dioxide (CO₂), and ethane (C₂H₆) on the ν₁ band of methane at a resolution of 0.35 cm^-1 were obtained. The validation of the approach showed that the helium content in natural gas can be measured with an uncertainty of 1 mol% at a sample pressure of 50 bar. The measurement precision can be increased to 0.01 mol% by using a high-resolution spectrometer. The described method does not claim to replace helium detectors, but it can be considered a valuable addition to Raman gas analysis of natural gas in developing an all-in-one device. The possibilities for further improvement of the approach are also discussed.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"784-796"},"PeriodicalIF":2.2,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142387450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Local Adaptive Fusion Regression (LAFR) for Local Linear Multivariate Calibration: Application to Large Datasets.","authors":"Robert Spiers, John H Kalivas","doi":"10.1177/00037028241308538","DOIUrl":"10.1177/00037028241308538","url":null,"abstract":"<p><p>Impeding linear calibration models from accurately predicting target sample analyte amounts are the target sample-wise deviations in measurement profiles (e.g., spectra) relative to calibration samples. Target sample measurement shifts are due to uncontrollable factors, compositely termed matrix effects, such as temperature, instrument drift, and sample composition divergences relative to analyte and other species amounts altering inter and intramolecular interactions. One approach to circumvent the matrix effect matching problem is to use local modeling where a library with thousands of samples and respective reference analyte values is mined for unique calibration sets matched to each target sample, including analyte amounts between calibration and target samples. Current local modeling methods suffer because it is wrongly assumed similar measurements between calibration and target samples translate to a complete locally matched calibration set. Measurements can be similar, but the underlying matrix effects (and analyte amount) can be drastically different. The presented procedure named local adaptive fusion regression (LAFR) solves this matrix effect matching problem with crucial local modeling paradigm shifts. Expertise with LAFR is unnecessary because input hyperparameters are self-optimized. The capabilities of LAFR to form highly dense localized linear calibration sets matched to target samples spectrally and analyte amounts are verified using a well-studied nonlinear benchmark near-infrared (NIR) meat dataset, a NIR sugarcane dataset covering four major process steps with multiple subgroups within, and a NIR soil database of 98 910 samples spanning the contiguous USA. While LAFR is tested on NIR datasets, it is applicable to other measurement systems affected by matrix effects in a broad sense.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"797-807"},"PeriodicalIF":2.2,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143021984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated Optics Waveguides and Mesoporous Oxides for the Monitoring of Volatile Organic Compound Traces in the Mid-Infrared.","authors":"Felix Frank, Bettina Baumgartner, Mattias Verstuyft, Nuria Teigell Beneitez, Jeroen Missinne, Dries Van Thourhout, Gunther Roelkens, Bernhard Lendl","doi":"10.1177/00037028241300554","DOIUrl":"10.1177/00037028241300554","url":null,"abstract":"<p><p>Volatile organic compounds (VOCs) are an ever-growing hazard for health and environment due to their increased emissions and accumulation in the air. Quantum cascade laser-based infrared (QCL-IR) sensors hold significant promise for gas monitoring, thanks to their compact, rugged design, high laser intensity, and high molecule-specific detection capabilities within the mid-infrared spectrum's fingerprint region. In this work, tunable external cavity QCLs were complemented by an innovative germanium-on-silicon integrated optics waveguide sensing platform with integrated microlenses for efficient backside optical interfacing for the tunable laser spectrometer. The waveguide chip was coated with a mesoporous silica coating, thereby increasing the signal by adsorptive enhancement of VOCs while at the same time limiting water vapor interferences. Different least square fitting methods were explored to deconvolute the resulting spectra, showing subparts-per-million by volume (sub-ppmv) limits of detection and enrichment factors of up to 22 000 while keeping the footprint of the setup small (29 × 23 × 11 cm³). Finally, a use-case simulation for the continuous detection of VOCs in a process analytical technology environment confirmed the high potential of the technique for the monitoring of contaminants. By successfully demonstrating the use of photonic waveguides for the monitoring of VOCs, this work offers a promising avenue for the further development of fully integrated sensors on a chip.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"842-851"},"PeriodicalIF":2.2,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12053257/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142845702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Interlaboratory Study to Minimize Wavelength Calibration Uncertainty Due to Peak Fitting of Reference Material Spectra in Raman Spectroscopy.","authors":"Dirk Lellinger, James Thomson, Nicolas Coca-Lopez, Afroditi Ntziouni, Nikolaos Nikoloudakis, María Fernández-Álvarez, Nina Jeliazkova, Miguel A Bañares, Raquel Portela, Enrique Lozano Diz","doi":"10.1177/00037028251330654","DOIUrl":"https://doi.org/10.1177/00037028251330654","url":null,"abstract":"<p><p>Raman spectroscopy is a powerful characterization technique with increasing applications that would greatly benefit from data harmonization. Several standards deal with calibration in Raman spectroscopy, but no detailed procedure covers the complete calibration of an instrument, including both spectral axes, from reference material spectra generation to data processing. Moreover, the type of reference materials, the quality of the recorded spectra and the choice of the fitting functions are critical for obtaining precise and reliable reference data for calibration. This report describes the challenges and importance of peak fitting for Raman signal calibration based on an interlaboratory study with 10 different instruments. Spectra of neon emission, silicon, calcite, and polystyrene were fitted using common peak shapes, observing that Gaussian, Pearson IV, Voigt, and Voigt shapes are preferred for these materials, respectively. An analysis of the effect on the fitting of the signal-to-noise ratio (S/N) recommends a minimum value of 100 for a Raman peak if it should be used to calibrate a Raman instrument. Some factors that might affect the peak shape of the Raman signal, such as the physical and chemical properties of the sample, the nature of the electronic transitions, the instrument response and the spectral resolution are discussed. The results highlight the role of peak fitting analysis in improving the quality and reliability of Raman spectra calibration and, thus, enhancing data transfer and comparability, especially for handheld and portable Raman analyzers, as well as applications based on quantification, multivariate data analysis, and other complex processing steps.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"37028251330654"},"PeriodicalIF":2.2,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143959689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enzyme Dynamics in Attoliter-Volume Electrochemical Zero-Mode Waveguides with On-Demand In Situ Hydrogen Peroxide Delivery and Consumption.","authors":"Jarek Metro, Julius Reitemeier, Paul W Bohn","doi":"10.1177/00037028251329956","DOIUrl":"https://doi.org/10.1177/00037028251329956","url":null,"abstract":"<p><p>Physiological systems are not at equilibrium and undergo time-dependent fluctuations, making it challenging to relate in vitro studies to in vivo biomolecular behavior. To bridge this gap, enzyme dynamics can be studied in the presence of controlled perturbations that recapitulate the intracellular environment. Here, we report an approach to the study of reactive oxygen species (ROS) based on the in situ manipulation of hydrogen peroxide (H₂O₂) levels in functionalized nanopore-based electrochemical zero-mode waveguide (EZMW) arrays, with each nanopore presenting small numbers of immobilized horseradish peroxidase (HRP) enzyme molecules. H₂O₂ is generated or consumed within the attoliter volume of the EZMW nanopores by poising an embedded ring electrode to suitable potentials, and the resulting effect on apparent turnover of HRP under non-equilibrium conditions is monitored using the enzymatically accelerated conversion of the non-fluorescent probe Amplex Red to fluorescent resorufin. A Nafion membrane is placed on the top surface of the EZMW array, providing a cation permselective barrier to transport in, or out, of the EZMW nanopores, thereby improving the sensitivity of the experiment by sequestering enzymatically generated resorufin in the attoliter volume of the EZMW nanopores. By fabricating arrays presenting 441 individual reaction volumes in parallel, distinct changes in population dynamics in the presence of in situ H₂O₂ generation or consumption are characterized with respect to temporal evolution and magnitude of the H₂O₂ aliquot delivered. This approach presents a promising avenue for studying biomolecular reactions in spatiotemporally controlled chemical environments that can mimic the non-equilibrium conditions encountered in vivo.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"37028251329956"},"PeriodicalIF":2.2,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143960263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stoichiometric Control of Bismaleimide Conjugation of DNA to Silica Surfaces Through Quantitative Fluorescence Analysis of Thiolated DNA.","authors":"Grant J Myres, Jay P Kitt, Joel M Harris","doi":"10.1177/00037028251332617","DOIUrl":"https://doi.org/10.1177/00037028251332617","url":null,"abstract":"<p><p>Surface immobilization of DNA for biosensing or separations applications requires covalent attachment chemistry that is efficient, reproducible, and stable. In this work, an approach to link thiol-functionalized DNA to thiol-modified silica surfaces using N,N'-1,4-phenylene-bismaleimide is optimized by developing an efficient, one-pot synthesis of the maleimide-conjugated DNA followed by its immediate reaction with thiolated porous silica particles. The methodology takes advantage of a Michael addition reaction that couples a phenyl-bismaleimide cross-linking reagent and thiol-modified DNA to form a monomeric DNA-maleimide conjugate. The 1:1 stoichiometry of this reaction must be carefully controlled to avoid excess thiol-DNA, which generates unreactive bismaleimide-linked DNA dimers, or excess bismaleimide, which competes with the DNA-maleimide conjugate for reaction with the thiolated silica surface. To achieve control over the reaction forming the DNA conjugate, we adapt a fluorescence assay for free-thiols using 7-diethylamino-3-(4-maleimidophenyl)-4-methyl-coumarin (CPM) to determine the concentration of thiol-modified DNA that emerges from its synthesis, disulfide labeling, reduction to a thiol, and purification. The fluorescence response of the CPM reagent was calibrated using reduced glutathione as a standard, which allowed determination of the concentrations of thiolated-DNA and control over the stoichiometry of its reaction with a bismaleimide linker. The maleimide-conjugated DNA product thus formed was then reacted with thiolated-silica in order to bind the DNA to the internal surfaces of porous silica, whose surface populations were determined in individual particles by confocal Raman microscopy. Self-modeling curve resolution of the Raman spectra of surface-bound molecules validated the efficiency of the bismaleimide:thiolated DNA reaction, which provided stoichiometric control over formation of the monomeric DNA-maleimide conjugate and its optimized reaction with thiolated-silica surfaces.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"37028251332617"},"PeriodicalIF":2.2,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143952566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction of Secondary Structure Content of Proteins Using Raman Spectroscopy and Self-Organizing Maps.","authors":"Marco Pinto Corujo, Pavel Michal, Dale Ang, Lindo Vivian, Nikola Chmel, Alison Rodger","doi":"10.1177/00037028251335051","DOIUrl":"https://doi.org/10.1177/00037028251335051","url":null,"abstract":"<p><p>Proteins are biomolecules with characteristic three-dimensional (3D) arrangements that render them different vital functions. In the last 20 years, there has been a growing interest in biopharmaceutical proteins, especially antibodies, due to their therapeutic application^. The functionality of a protein depends on the preservation of its native form, which under certain stressing conditions can undergo changes at different structural levels that cause them to lose their activity.¹ Although mass spectrometry is a powerful technique for primary structure determination, it often fails to give information at higher order levels. Like infrared (IR), Raman spectra are well known to contain bands (especially the amide I from 1625-1725cm^-1) that correlate with secondary structure (SS) content. However, unlike circular dichroism (CD), the most well-established technique for SS analysis, Raman spectroscopy allows a much wider ranges of optical density, making possible the analysis of highly concentrated samples with no prior dilution. Moreover, water is a weak scatterer below 3000 cm^-1, which confers Raman an advantage over IR for the analysis of complex aqueous pharmaceutical samples as the signal from water dominates the amide I region. The most traditional procedure to extract information on SS content is band-fitting. However, in most cases, we found the method to be ambiguous, limited by spectral noise and subjected to the judgment of the analyzer. Self-organizing maps (SOM) is a type of self-learning algorithm that organizes data in a two-dimensional (2D) space based on spectral similarity and class with no bias from the analyzer and very little effect from noise. In this work, a set of protein spectra with known SS content were collected in both solid and aqueous state with back-scatter Raman spectroscopy and used to train a SOM algorithm for SS prediction. The results were compared with those by partial least squares (PLS) regression, band-fitting, and X-ray data in the literature. The prediction errors observed by SOM were comparable to those by PLS and far from those obtained by band-fitting, proving Raman-SOM as viable alternative to the aforementioned methods.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"37028251335051"},"PeriodicalIF":2.2,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143958924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}