Applied Spectroscopy最新文献

{"title":"Theoretical Calculation and Simulation of Peak Distortion of Absorption Spectra of Complex Mixtures.","authors":"Rui Cheng, Thomas G Mayerhöfer, Johannes Kiefer","doi":"10.1177/00037028241297179","DOIUrl":"10.1177/00037028241297179","url":null,"abstract":"<p><p>Attenuated total reflection (ATR) spectroscopy in infrared is a standard tool used in most analytical labs, as it allows a rapid chemical analysis with virtually no sample preparation. However, when the sample contains materials with a high refractive index, special care must be taken as the resulting data may be severely biased. This article reports a theoretical approach to correcting distorted ATR spectra. Starting from Snell's law, Lorenz model and Fresnel's equations are combined to obtain the complex relationship between optical constants. With calculating the real and imaginary parts, that is, <math><mi>n</mi><mo>(</mo><mi>ν</mi><mo>)</mo></math> and <math><mi>k</mi><mo>(</mo><mi>ν</mi><mo>)</mo></math>, respectively, of the complex refractive index from the absorption spectrum, a model for mixtures comprising of a liquid and a solid is established. The effects of distortion and potential misinterpretation of the data are discussed. Proof-of-concept experiments with mixtures of carbonaceous materials and toluene confirm the theoretically predicted observations.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"852-861"},"PeriodicalIF":2.2,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12053103/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142799264","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":"Spectroscopic Study of Micro-/Nano-Hydroxyapatite Polymer Composites Modified with Carbon Nanofibers.","authors":"Anna Kołodziej, Małgorzata Rachwał, Elżbieta Długoń, Magdalena Ziąbka, Aleksandra Wesełucha-Birczyńska","doi":"10.1177/00037028251316290","DOIUrl":"10.1177/00037028251316290","url":null,"abstract":"<p><p>Nowadays, novel biomaterials are under intense research because they are part of promising therapies for the treatment of age-related diseases such as osteoporosis and bone defects. In the presented study, composites of poly(ε-caprolactone) (PCL), micro and nano hydroxyapatite (µ-HAp and n-HAp) and carbon nanofibers (CNFs) were prepared. The influence of additives on polymeric matrix was analyzed using scanning electron microscopy (SEM), Raman micro-spectroscopy, Raman mapping, and two-dimensional correlation spectroscopy (2D-COS). The bioactivity in vitro was evaluated by a 21-day incubation of prepared membranes in simulated body fluid (SBF). It was concluded that additives can behave as crystallization nuclei of PCL, but they are also located across the entire surface of PCL spherulites, not only in the center. With an increasing content of HAp additives, polymeric spherulites become smaller. The type of HAp (µ-HAp or n-HAp) influences the PCL matrix differently, as confirmed by 2D-COS. The component whose addition leads to most significant changes in the polymer is CNFs; polymeric spherulites are small to the extent that they are not distinguishable, and the overall amorphousness of the polymer is the highest among all tested materials, as is its hydrophobicity. The bioactivity test indicated that the membrane with the greatest potential for use as a biomaterial in bone tissue engineering is one consisting of n-HAp (15 wt%) and CNFs, as very uniform coverage of the produced apatite was observed on the surface of this membrane after incubation in SBF.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"741-755"},"PeriodicalIF":2.2,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143432369","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":"Comparison of a Quantum Cascade Laser and an Interband Cascade Laser for the Detection of Stable Carbon Dioxide Isotopes Using Tunable Laser Absorption Spectroscopy.","authors":"Ponkanok Nitzsche, Cem Dinc, Jens Goldschmidt, Leonard Nitzsche, Jürgen Wöllenstein, Katrin Schmitt","doi":"10.1177/00037028241291157","DOIUrl":"10.1177/00037028241291157","url":null,"abstract":"<p><p>Quantum cascade lasers (QCLs) and interband cascade lasers (ICLs) are widely used as light sources in tunable laser absorption spectroscopy because they emit in the mid-infrared region where many strong and characteristic absorption bands are present. In this paper, we compare the performance of these lasers emitting at about 2310.1 cm^-1 to determine an optimal light source for detecting isotopic ratios of carbon dioxide (CO₂). Our results show that the QCL has a higher relative intensity noise of up to 15 dBc/Hz compared to the ICL over the entire measured frequency range. In addition, it has a higher frequency fluctuation. However, the maximum tuning range of the QCL is up to 5.2 cm^-1 compared to up to 3.8 cm^-1 for the ICL. Both lasers lose more than half of their tuning range when the tuning rate is increased to 10 kHz. When measuring the isotope ratio of CO₂, an uncertainty in the <math><msup><mi>δ</mi><mn>13</mn></msup></math> value of <math><msubsup><mi>σ</mi><mrow><mrow><mn>13</mn><mi>C</mi><mo>,</mo><mi>min</mi></mrow></mrow><mrow><mrow><mi>ICL</mi></mrow></mrow></msubsup><mo>=</mo><mn>0.17</mn></math>‰ was achieved with the ICL and of <math><msubsup><mi>σ</mi><mrow><mrow><mn>13</mn><mi>C</mi><mo>,</mo><mi>min</mi></mrow></mrow><mrow><mrow><mi>QCL</mi></mrow></mrow></msubsup><mo>=</mo><mn>0.42</mn></math>‰ with the QCL, both at an integration time of 0.2 s. In summary, the QCL is more appropriate for applications that require a larger spectral tuning range, such as the measurement of a complex gas mixture, while the ICL has an excellent signal-to-noise ratio and is therefore better suited for applications that require higher precision.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"862-871"},"PeriodicalIF":2.2,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142613925","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":"Rapid-Scan Fourier Transform Infrared Difference Spectroscopy with Two-Dimensional Correlation Analysis to Show the Build-Up of Light-Adapted States in Bacterial Photosynthetic Reaction Centers.","authors":"Alberto Mezzetti, Marco Malferrari, Giovanni Venturoli, Francesco Francia, Winfried Leibl, Isao Noda","doi":"10.1177/00037028241304806","DOIUrl":"10.1177/00037028241304806","url":null,"abstract":"<p><p>Time-resolved, rapid-scan Fourier transform infrared (FT-IR) difference spectra have been recorded upon illumination on photosynthetic reaction centers (RCs) from <i>Rhodobacter sphaeroides</i> under fixed hydration conditions (relative humidity = 76%). Two different illumination schemes were adopted. Whereas the use of a laser flash (duration: 7 ns) made it possible to follow the kinetics of recombination of the light-induced state P⁺Q_A^- to the neutral state PQ_A, the use of a 20.5 s continuous light from a lamp made it possible to follow both the build-up of a steady-state P⁺Q_A^- population and its decay to PQ_A. Comparison between P⁺Q_A^-/PQ_A FT-IR difference spectra obtained under (or 650 ms after) continuous illumination and obtained after one laser flash show small but meaningful differences, reflecting structural changes in the light-adapted state produced by the 20.5 s period of illumination. These differences are strikingly similar to those observed when comparing FT-IR difference spectra reflecting charge separation in photosystem II in light-adapted states and non-light-adapted states (c.f. Sipka et al., \"Light-Adapted Charge-Separated State of Photosystem II: Structural and Functional Dynamics of the Closed Reaction Center\". Plant Cell. 2021. 33(4): 1286-1302). Two-dimensional correlation spectroscopy analysis revealed that in all the observed series of time-resolved FT-IR difference spectra (under illumination, after illumination, and after a laser flash), marker bands at 1749, 1716, and 1668 cm^-1 all evolve synchronously, demonstrating that electron transfer reactions and protein backbone response (at least the one reflected by the 1668 cm^-1 band) are strongly correlated. Conversely, for spectra under and after continuous illumination, many asynchronicities are observed for (still unassigned) bands throughout the whole 1740-1200 cm^-1 region, reflecting a more complicated molecular scenario in the RC upon build-up of the light-adapted state and during its relaxation to the resting neutral state.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":" ","pages":"756-766"},"PeriodicalIF":2.2,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143027828","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 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}