Tunable diode laser absorption spectroscopy (TDLAS) is combined with an extreme learning machine (ELM) model, tailored by genetic algorithm (GA) parameter searching, to produce a more robust analytical method for trace gas analysis of ethylene.
Per- and poly-fluoroalkyl substances (PFAS) are a family of potentially thousands of synthetic compounds that have long been used in the manufacture of a variety of common products with stain-repellent and nonstick properties. Their signature strong fluorine and carbon bonds make them difficult to break down and, as a result, they are among the most persistent of today’s environmental pollutants. Alarmingly, PFAS can be found in drinking water and have been shown to accumulate in the body with the potential to cause multiple health problems, such as hormone disruption and cancer. Advances in mass spectrometry have facilitated the detection of known PFAS contaminants as well as the identification of poorly studied and novel compounds in watersheds. This article explores the detection of known and novel PFAS contaminants in aqueous film-forming foams and raw drinking water sources in North Carolina, using new advances in mass spectrometry and data acquisition to improve identification and quantitation.
In this article, tunable diode laser absorption spectroscopy (TDLAS) is used to measure ammonia leakage, where a new denoising method combining empirical mode decomposition with the Savitzky-Golay smoothing algorithm (EMD-SG) is proposed to improve the signal-to-noise ratio (SNR) of absorbance signals.
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.
Analysis of the compositional variation in living cells is essential for understanding biological processes. Single-cell elemental analysis by triple-quadrupole ICP-MS is emerging as a selective, highly sensitive, and potentially high-throughput technique for the study of constitutive elements, and uptake of metallodrugs (or metal-containing nanomaterials) in single cells.
Detecting metal elements in liquid samples cannot be done efficiently by only using LIBS, but when the technique is combined with appropriate membrane materials, rapid analysis of solution samples can be realized.
Determining the printing sequences of crossed writings and seal stamps is often difficult because the most common methods used are expensive, time-consuming, and cumbersome. A new method using Raman spectral area scanning offers a better alternative while conducting pigment analysis and determining intersection sequences of writings and seal stamps. We explain why.
In this interview, originally published in European Spectroscopy News 44 in 1982, Dave Briggs sat down with 1981 Nobel Prize winner Kai Manne Börje Siegbahn to discuss his career and work in spectroscopy.
This study aimed to establish a fast, accurate method for quality evaluation of herbal medicine using NIR and chemometrics with ultraviolet-visible spectrophotometry (UV-vis) as a standard method to determine the total flavonoids content.
Evaluation of the UV-vis spectra of the reaction product of ytterbium (III) with hematoxylin (HE) indicates the formation of a rare earth complex that further reacts with marine mammal DNA, indicating the potential that this complex may have anti-tumor properties.
Because of their corrosive properties, corrosive lipids are challenging to analyze by ATR-FT-IR. Repeated and prolonged analysis can damage many ATR crystals. Diamond ATR is a better choice for such applications than other ATR crystal materials like ZnSe and Ge. This application note examines a corrosive liquid as it becomes progressively more concentrated using diamond ATR.
This study uses Fourier transform infrared (FT-IR) spectroscopy to analyze how the globular protein ovalbumin's secondary structures transition under varying pH conditions in the presence of the cosolvent xylitol, highlighting the role of noncovalent interactions in these conformational changes.
Utilizing a low-altitude unmanned aerial vehicle (UAV), a hyperspectral remote-sensing system can identify key grass species indicating grassland degradation, developing an ASI index and classification rules and leveraging spectral differences and plant senescence reflectance to effectively monitor and evaluate grassland conditions and degradation.
The “selective fluorescence quenching effects” of Fe3+ ions on carbon dots are examined to gain a more comprehensive understanding of the interactions of metal ions with a variety of fluorescent materials.
Gas chromatography–mass spectrometry (GC–MS) with cold electron ionization (EI) is based on interfacing the GC and MS instruments with supersonic molecular beams (SMB) along with electron ionization of vibrationally cold sample compounds in SMB in a fly-through ion source (hence the name cold EI). GC–MS with cold EI improves all the central performance aspects of GC–MS. These aspects include enhanced molecular ions, improved sample identification, an extended range of compounds amenable for analysis, uniform response to all analytes, faster analysis, greater selectivity, and lower detection limits. In GC–MS with cold EI, the GC elution temperatures can be significantly lowered by reducing the column length and increasing the carrier gas flow rate. Furthermore, the injector temperature can be reduced using a high column flow rate, and sample degradation at the cold EI fly-through ion source is eliminated. Thus, a greater range of thermally labile and low volatility compounds can be analyzed. The extension of the range of compounds and applications amenable for analysis is the most important benefit of cold EI that bridges the gap with LC–MS. Several examples of GC–MS with cold EI applications are discussed including cannabinoids analysis, synthetic organic compounds analysis, and lipids in blood analysis for medical diagnostics.
The case studies presented here successfully demonstrate the use of inline Raman spectroscopic analysis to estimate solvent content during the solvent exchange and distillation operations in the synthesis of active pharmaceutical ingredients.
Detecting metal elements in liquid samples cannot be done efficiently by only using LIBS, but when the technique is combined with appropriate membrane materials, rapid analysis of solution samples can be realized.
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).
Webinar Date/Time: Mon, Mar 27, 2023 11:00 AM EDT
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.
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).
This study explores the enhanced performance of modified alternating least squares (MALS) over alternating least squares (ALS) in analyzing infrared and Raman image spectral data, highlighting the stability and computational efficiency of MALS.
The COVID-19 vaccine, and the speed at which it was developed, is the medical breakthrough of our lifetimes.
Software tools for ICP-MS and ICP-OES can help analysts to simplify method setup and reduce the potential for errors.
Here, we compare XRD and FT-IR for analysis of suspect counterfeit pharmaceuticals to determine how the techniques can be used in a complementary fashion.
In this study, a glycerol-fed, lab-scale E. coli bioprocess producing representative pharmaceutical compounds was monitored offline with a portable, high-sensitivity Raman spectrometer.
In this study, X-ray fluorescence (XRF) spectroscopy was used to analyze heavy metals in five traditional Mongolian medicines, and the results were compared to those obtained using ICP-MS.
This article discusses how FT-IR and SERS is being used to detect counterfeit pharmaceutical drugs.