We describe the fabrication of an underwater time-gated standoff Raman sensor, consisting of a custom Raman spectrometer, custom scanner, and commercial diode-pumped pulsed 532-nm laser all located inside pressure housing. The Raman sensor was tested in the laboratory with samples in air, a tank containing tap water and seawater, and in the coastal Hawaiian harbor. We demonstrate our new system by

Conventional methods for measuring the concentration of deuterium in body fluids are by either isotope ratio mass spectrometry or Fourier transformed infra-red transmission (FTIR) spectroscopy. The latter method is often preferred as it is less expensive and time consuming; however, having a lower sensitivity means a larger sample volume is required. This study investigated an alternative FTIR spectroscopic

The resonance Raman spectra of bacterial carotenoids have been employed to identify bacterial strains and their intensity changes as a function of ultraviolet (UV) radiation dose have been used to differentiate between live and dead bacteria. In addition, the resonance-enhanced Raman spectra enabled us to detect bacteria in water at much lower concentrations (∼108 cells/mL) than normally detected spectroscopically

Online measurements of the raw gas composition, including tars and water, during biomass gasification provide valuable information in fundamental investigations and for process control. Mainly consisting of hydrocarbons, tars can, in principle, be measured using Fourier transform infrared (FT-IR) spectroscopy. However, an instrument subjected to raw gas runs the risk of condensation of tars on optical

Pottery sherds from Teotihuacan, Mexico, belonging to the Formative and Classic periods (150 BCE–700 CE) were investigated using laser-induced breakdown spectroscopy (LIBS) and inductively coupled plasma optical emission spectrometry (ICP-OES). LIBS results show that most of the investigated samples have primarily the same elemental composition. Nevertheless, there are also a few sherds that could

Plastics have been increasingly used to create modern and contemporary art and design, and nowadays, museum collections hold numerous objects completely or partially made of plastics. However, the preservation of these materials is still a challenging task in heritage conservation, especially because some plastics show signs of degradation shortly after their production. In addition, different degradation

The chlorinity of deep-sea hydrothermal fluids, representing one of the crucial deep-sea hydrothermal indicators, indicates the degree of deep phase separation of hydrothermal fluids and water/rock reactions. However, accurately measuring the chlorinity of high-temperature hydrothermal fluids is still a significant challenge. In this paper, a piecewise chlorinity model to measure the chlorinity of

The knowledge of the spectroscopic parameters of the elemental emission lines is important for diagnostics of laser-induced plasmas and the application of calibration-free/fundamental parameters analytical methods. In this paper, we used the recently proposed Time-Independent Extended C-Sigma (TIECS) method for determining, for the first time, the transition probabilities and Stark broadening coefficients

The objective of this work is to demonstrate the potential of near infrared (NIR) spectroscopy for common screening of falsified medicines in the field by means of a device-independent universal discrimination approach. In order to provide a useful discrimination tool to protect people from low-quality medical products, not only is a low-cost and portable screening device necessary, but a reference

Tire evidence is a form of trace evidence that is often overlooked in today's forensics, while frequently found at crime or accident scenes, usually in the form of skid marks. The pattern of the tire skid mark has been used before to link a tire or car to a scene, but the widespread use of anti-lock braking systems makes this an almost impossible and abandoned route of analysis. With this is mind,

An optical diagnostic, based on laser-induced fluorescence (LIF), has been developed for on-engine measurements of real-time fuel dilution of engine oil, or fuel in oil (FiO). Fuel dilution of oil is broadly relevant to advancing engine technology including durability, calibration, and catalyst-system management, and believed to promote destructive stochastic pre-ignition (SPI) during high-load engine

The peroxide value (PV) of edible oils is a measure of the degree of oxidation, which directly relates to the freshness of the oil sample. Several studies previously reported in the literature have paired various spectroscopic techniques with multivariate analyses to rapidly determine PVs using field portable and process instrumentation; those efforts presented ‘best-case’ scenarios with oils from

In this article the total reflection X-ray fluorescence (TXRF) analysis was used for determination of element concentrations in three isolated peripheral blood components: lymphocytes, erythrocytes, and plasma, collected from 36 healthy donors (15 men and 21 women) from eastern Poland. The studied blood components were isolated from whole peripheral blood using Histopaque-1077 density gradient centrifugation

The energy efficiency of heterogeneous catalytic processes may be improved by using mid-infrared light to excite gas-phase reactants during the reaction, since vibrational excitation of molecules has been shown to increase their reactivity at the gas-catalyst interface. A primary challenge for such light-enabled catalysis is the need to ensure close coupling between light-excited molecules and the

Essential oils are complex mixtures of organic substances with large commercial importance in the pharmaceutical, food, fragrance, and cosmetic industries due to their organoleptic and biological properties. Also, these materials are also luminescent what has taken several studies about its potential uses for the detection and quality control of essential oils, imaging, and for the investigation of

This work aims to investigate changes induced by low energy radiation in adipose and muscular tissues employing autofluorescence and Raman spectroscopic techniques. X-rays beams expositions with 25 and 35 kV at 0.11, 1.1 and 2.1 Gy radiation dose levels were applied. Changes in Raman line intensities at specific bands assigned to collagen, proteins and lipids were observed. Autofluorescent analysis

The adipose tissue presents structural and functional changes in obesity and type 1 diabetes (T1DM). In obesity, the size and number of adipocytes and the adipokines' secretion increase. In T1DM, a loss of adipose tissue suggests changes in the metabolic activity of this tissue. A significant challenge is to find alternative non-invasive methods to evaluate molecular changes in adipose tissue related

Ammonia (NH3) is regarded as an important NOx precursor and also as an effective reductant for NOx removal in energy utilization through combustion, and it has recently become an attractive non-carbon alternative fuel. To have a better understanding of thermochemical properties of ammonia, accurate in-situ detection of ammonia in high temperature environments is desirable. Ultraviolet (UV) absorption

Algorithms to objectively compare the circular dichroism spectra of biopharmaceuticals, as a measure of consistent higher order structure, and are sensitive to errors in spectropolarimeter wavelength calibration. A public database, the Protein Circular Dichroism Data Bank [PCDDB] contains 108 unique calibration spectra of d-camphor-10-sulphonic acid [CSA], mainly collected on synchrotron-based instruments

Generation of CO2 from Nordic fulvic acid (FA) solution in the presence of goethite (α-FeOOH) were observed in FA-goethite interaction experiments at 25–80 °C. CO2 generation processes observed by gas cell infrared (IR) spectroscopy indicated two steps: the zeroth order slower CO2 generation from FA solution commonly occurring in the heating experiments of the FA in the presence and absence of

In recent years, the native food industry in Australia has increased in both value and volume due to the discovery of a wide range of phytochemicals (e.g. vitamin C, polyphenols) that have potential health benefits. Thus, plant organs and tissues of these native plants are used in a wide range of applications. In particular, the kernel of a native plum, the Kakadu plum (Terminalia ferdinandiana, Combretaceae)

There is growing interest in the use of algorithms to objectively compare near UV spectra of protein biopharmaceuticals in a regulated environment. Such use will require that the methods be validated, with ICH Q2(R1) currently being the key document. A key aspect of such validation is to understand how robust the method is to experimental variation. Noise-free simulated spectra, obtained by fitting

Qualitative and quantitative Raman and infrared (IR) measurements on NaNO3 solutions have been carried out over a wide concentration range (5.56 · 10-6 – 7.946 mol/L) in water and heavy water. The Raman spectra were measured from 4000 cm-1 to low wavenumbers at 45 cm-1. Band fit analysis on the profile of the 1047 cm-1 – band, ν1(a1') NO3- measured at high resolution at 0.85 cm-1 produced a small

The Attenuated Total Reflection (ATR) technique coupled with a microscope allows analysis of specimens without any preparation, spatially correlated with the specimen’s morphology. These characteristics make micro-ATR systems very useful for studying gemstones and in particular amber samples. Indeed, in this report the micro-ATR technique was used to characterize three Burmite samples, as case studies

Implementing remote, real-time spectroscopic monitoring of radiochemical processing streams in hot cell environments requires efficiency and simplicity. The success of optical spectroscopy for the quantification of species in chemical systems highly depends on representative training sets and suitable validation sets. Selecting a training set (i.e., calibration standards) to build multivariate regression

Raman spectroscopy has been used extensively to calculate CO2 fluid density in many geological environments, based on the measurement of the Fermi diad split (Δ; cm-1) in the CO2 spectrum. While recent research has allowed the calibration of several Raman CO2 densimeters, there is a limit to the inter-laboratory application of published equations. These calculate two classes of density values for

Spectroscopy rapidly captures a large amount of data that is not directly interpretable. Principal Components Analysis (PCA) is widely used to simplify complex spectral datasets into comprehensible information by identifying recurring patterns in the data with minimal loss of information. The linear algebra underpinning PCA is not well understood by many applied analytical scientists and spectroscopists

The magnitude of infectious diseases in 21st century created an urgent need for point-of-care diagnostics. Critical shortages in reagents and testing kits have had a large impact on the ability to test patients with a suspected parasitic, bacteria, fungal and viral infections. New point-of-care tests need to be highly sensitive, specific, and easy to use and provide results in rapid time. Infrared

In nature a wide variety of minerals are known with the general formula X2M(TO4)2·2(H2O) and an important group is formed by minerals with T = As. Most of these occur as minor or trace minerals in environments such as hydrothermal alterations of primary sulfides and arsenides. X-ray Photoelectron Spectroscopy (XPS) and Raman microspectroscopy have been utilized to study the chemistry and crystal structure

In this work, we report the application of Raman microspectroscopy for analysis of the refractive index of a range of tissue phantoms. Using both a custom-developed setup with visible laser source and a commercial micro-spectrometer with near infrared laser, we measured the Raman spectra of gelatin hydrogels at various concentrations. By building a calibration curve from measured refractometry data

Fluorine can negatively interfere with leach and smelting processes during mineral processing1,2. Real-time knowledge of the concentration and mineral hosts of fluorine in a mineral processing ore stream is important to protect process line equipment and product. Currently only offline methods of detection are available. Online sensors that determine specific fluorine-bearing mineral concentration

Exposing polymers to high-pressure and supercritical CO2 is a useful approach in polymer processing. Consequently, the mechanisms of polymer-polymer interaction under such conditions are worthy of further investigation. Two-dimensional (2D) correlation analysis and 2D disrelation mapping were applied to datasets of PCL(Polycaprolactone)/PLA (Poly(lactic acid)) blend with or without high-pressure CO2

Here we present an augmented form of two-dimensional correlation spectroscopy (2DCOS), that integrates in a single format data from spectroscopic and multiple non-spectroscopic sources for analysis. The integration is effected by augmenting every spectrum in a hyperspectral data set with relevant non-spectroscopic data to permit two-dimensional correlation analysis of the ensemble of augmented spectra

Characterization and quantification of individual whey proteins is crucial in many industrial dairy processes. With labor-intensive wet-chemical methods still being used as reference, a rapid quantification method for individual whey proteins is yet to be established. In this work Fourier Transform Mid-Infrared (FT-MIR) spectroscopy and Fourier Transform Near-Infrared (FT-NIR) spectroscopy were investigated

Many medical devices contain metals that interface with the body. Additionally, embedded metal fragments from military wounds are typically not removed, to avoid the risk of morbidity associated with invasive surgery. The long-term health consequences of many of these materials are not thoroughly understood. To this end, we have exposed rats for up to one year to implanted single-element metal pellets

Etalon features in infrared spectra of stratified samples, their influence on the interpretation, and methods to circumvent their presence in infrared spectra have been in discussion for decades. This paper focuses on the application of a method originally developed to remove interference fringes in the mid-infrared spectra for far-infrared Fourier transform spectroscopy on thin polymer films. We show

Many spectra have a polynomial-like baseline. Iterative polynomial fitting (IPF) is one of the most popular methods for baseline correction of these spectra. However, the baseline estimated by IPF may have substantially error when the spectrum contains significantly strong peaks or have strong peaks located at the endpoints. First, IPF uses temporary baseline estimated from the current spectrum to

The detection and measurement of hydrocarbons is of high interest for a variety of applications, for example within the oil & gas industry from extraction throughout the complete refining process, as well as for environmental monitoring and for portable safety devices. This paper presents a highly sensitive, selective and robust tunable laser analyzer that has the capability to analyze several components

Tetracycline, an animal antibiotic, may remain in milk to cause harm to human health. For economic reasons, the abuse of antibiotics is becoming more and more common. Therefore, the abuse of tetracycline has alarmed the dairy industry and many countries such as New Zealand, China and USA have proposed strict standards. Surface-Enhanced Raman Scattering (SERS) is an emerging detection method which has

The full cross-referenced details for the following companion papers appearing in the August 74[08] 2020 issue of Applied Spectroscopy were inadvertently omitted. The full reference details should instead be:

The full cross-referenced details for the following companion papers appearing in the August 74[08] 2020 issue of Applied Spectroscopy were inadvertently omitted. The full reference details should instead be:

The peroxide value (PV) of edible oils is a measure of the degree of oxidation, which directly relates to the freshness of the oil sample. Several studies previously reported in the literature have paired various spectroscopic techniques with multivariate analyses to rapidly determine PVs using field portable and process instrumentation; those efforts presented ‘best-case’ scenarios with oils from

The full color version of Table I accompanying the paper entitled, “Reporting Guidelines to Increase the Reproducibility and Comparability of Research on Microplastics”, by Win Cowger, Andy M. Booth, Bonnie M. Hamilton, Clara Thaysen, Sebastian Primpke, Keenan Munno, Amy L. Lusher, Alexandre Dehaut, Vitor P. Vaz, Max Liboiron, Lisa I. Devriese, Ludovic Hermabessiere, Chelsea Rochman, Samantha N. Athey

In this technical note, we present an advanced thermospectroscopic imager based on a Fourier transform infrared (FTIR) spectrometer and a thermal camera. This new instrument can image both thermal emission and multispectral absorbance fields in a few seconds at a resolution of 4 cm-1 or less. The setup is made of a commercial FTIR spectrometer (Thermofisher Nicolet iS50R) synchronized to an IR camera

In the present work, nanoparticles-enhanced laser-induced breakdown spectroscopy (N.E.L.I.B.S.) has been used to analyze aluminum alloy. Though LIBS has numerous advantages, it suffers from low sensitivity and low detection limits compared to other spectrochemical analytical methods. However, using gold nanoparticles helps to overcome such drawbacks and enhances the LIBS sensitivity in analyzing aluminum

SO2, CS2 and H2S are important decomposition products of insulating gas SF6, and their types and contents are of great significance for the fault diagnosis of SF6 insulated equipment. In this paper, a method of combining ultraviolet absorption spectroscopy and least squares fitting is proposed for the quantitative calculation of SO2, CS2 and H2S mixed gases. All three gases have absorption peaks in

Minimally invasive cancer detection using bio-fluids is been actively pursued due to practical limitations of, though, better suited noninvasive and online in vivo methods. Saliva is one such clinically informative bio-fluid that offers advantage of easy and multiple sample collection. Despite its potential in cancer diagnostics, saliva analysis is challenging due to its heterogeneous composition.

We propose an approach for monitoring the concentration of dissociated carboxylic acid species in dilute aqueous solution. The dissociated acid species are quantified employing inline Raman spectroscopy in combination with Indirect Hard Modeling (IHM) and Multivariate Curve Resolution (MCR). We introduce two different titration-based Hard Model (HM) calibration procedures for a single mono- or polyprotic

Laser-induced carbon plasma in air undergoes various physicochemical processes that affect the kinetic chemistry of species of the plasma plume. We report the time- and space- resolved characterization of carbon plasma produced by infrared nanosecond laser into air at atmospheric pressure. Investigating the laser fluence effect highlights dissociation for fluences > 40 J cm-2, and recombination processes

Previously, we demonstrated that the intensities of cross peaks in a two-dimensional asynchronous spectrum could be enhanced via a change of the sequence of the corresponding 1D spectra. This unusual approach becomes useful when the determination of the sequential order of physicochemical events is not essential. However, we have not known whether the level of noise in the 2D asynchronous spectrum

This study presents the first results of a new type of hyperspectral imager in the longwave thermal radiation range from 8.0-14.0 µm which is simpler than readily available Fourier transform infrared spectroscopy (FTIR) based imagers. Conventional thermography images the thermal radiation from hot objects, but an accurate determination of temperature is hampered by the often unknown emissivities of

In this article a new data treatment based on time resolved photoluminescence are presented. It works as a Streak Camera for infrared. A Time resolved photoluminescence spectrum for the HgCd0.33Te0.67 sample at 120 K was performed and analyzed. Typical time resolved photoluminescence measurements, to compare our results with literature were conducted. An interpretation of the behavior for three different

Heroin is one of the most frequently seized drugs in the South-Eastern Europe. Due to the position in the Balkan route, the Republic of Serbia keeps important role in suppression of the trafficking of heroin for domestic and foreign illegal market. This research is aimed to provide a good scientific approach in the field of seized heroin analysis. Two different forms of heroin are present in the illegal

Fourier transform (FT) spectroscopy is a versatile technique for studying the infrared (IR) optical response of solid-, liquid-, and gas-phase samples. In standard Fourier transform infrared (FT-IR) spectrometers, a light beam passing through a Michelson interferometer is focused onto a sample with condenser optics. This design enables us to examine relatively small samples, but the large solid angle

Characteristics of five subpopulation leukocytes in single-cell levels based on partial principal component analysis coupled with Raman spectroscopy were proposed to recognize the biochemical features of five subpopulation leukocytes. Using wavelet transform, the reconstructed spectra of the low-frequency wavelet coefficients were used to perform multiple principal component analysis based on segmented

The desire for portable Raman spectrometers is continuously driving the development of novel spectrometer architectures where miniaturisation can be achieved without the penalty of a poorer detection performance. Spatial heterodyne spectrometers are emerging as potential candidates for challenging the dominance of traditional grating spectrometers, thanks to their larger etendue and greater potential

The present study has investigated the transformation of sesame oil kept at low temperature during a definite period of time for refinement (called winterization) as an inactive drug ingredient by using two-dimensional difference spectra (2D-DS) analysis of spectra collected by a near-infrared (NIR) and mid-infrared (MIR) dual-wavelength spectrometer (NIR/MIR-DWS). The NIR and MIR spectra were measured

The low accessibility of natural gas fields and transporting pipelines requires portable online analyzers of the composition of natural gas, ensuring nearly chromatographic precision and capable of in situ analysis of a wide range of gases, including infrared-inactive ones (hydrogen, oxygen, nitrogen, chlorine). We have developed an express method of gas analysis meeting all the requirements for analysis

The formation of crystalline zinc soaps (zinc salts of fatty acids) in oil paint layers is a common sign of paint degradation. In this study, we have used infrared spectroscopy to systematically identify differences in structure and composition of crystalline zinc soap phases, and report data analysis methods for structure attribution in challenging oil paint samples. Supported by reported crystal

Analysis of nitrate ester explosives (e.g., nitroglycerine) using gas chromatography–vacuum ultraviolet spectroscopy (GC–VUV) results in their thermal decomposition into nitric oxide, water, carbon monoxide, oxygen, and formaldehyde. These decomposition products exhibit highly structured spectra in the VUV that is not seen in larger molecules. Computational analysis using time-dependent density functional