Raman Chemical Imaging technology is able to identify and differentiate multiple components in complex formulated nasal spray suspensions based on chemical makeup. Particle size distribution statistics for the ingredient of interest are produced in a rapid, objective and semi-automated manner. Both solitary and aggregated drug particle sizing information may be obtained.
The increasing use of pesticide testing coupled with reductions in maximum permissible residue levels of pesticides in food have driven demand for fast, sensitive, and cost-effective analytical methods for high-throughput screening of multiclass pesticides in food. Detection of 510 pesticides at low parts-per-billion levels can be achieved within minutes using orbital trap technology. The high resolving power of these systems enables accurate mass confirmation of all compounds, including isobaric pesticides. This article will provide an overview of current legislation and illustrate how mass spectrometry instrumentation can enable fast and accurate pesticide screening.
A number of clinical situations now call for high-sensitivity measurement of estrogens, including monitoring during female hormone replacement therapy, antiestrogen treatment, and estrogen deficiency in men. Traditional immunoassay methods and liquid chromatography–tandem mass spectrometry (LC–MS-MS) do not provide the sensitivity and selectivity required for these applications. In contrast, a gas chromatography–negative chemical ionization–tandem mass spectrometry (GC–NCI-MS-MS) platform can provide detection limits below 1 pg/mL when used in conjunction with the appropriate derivatization protocol, with very short cycle times.
The authors discuss a noninvasive method for determining early indications of the rejection of a kidney transplant.
The authors discuss progress in near-field IR microspectroscopy using a photothermal probe and show how it can be applied to the spectroscopic characterization of real-world samples.
This work shows that methods based on miniaturized near- and mid-infrared spectroscopy can be used effectively for the quality control of herbal medicines.
The use of filters in optical microscopy has become so commonplace that it is hard to find a biological microscope that does not have some type of filter accessory kit. For particular modalities, such as two-photon imaging, the use of optical filters is essential to make the method viable. Filter technology has progressed steadily over the past few decades, moving away from simple colored glass filters to complicated thin-film–based optical components. With optical densities commonly reaching values of 4 or greater, spectrally selective imaging has never been more accurate.
A simple method for extraction and concentration of trace organic compounds found in water for gas chromatography-mass spectrometry (GC-MS) analysis was developed. The method used 25 and 45 mL glass vials with a 5-10 µm thick polymer coatings for extraction of analytes from 20 and 40 mL water samples, respectively. Analytes were subsequently transferred from the polymer coating into an organic solvent, which was reduced in volume to 200-400 µL for analysis. A 10-20 µL sample from the vial was transferred to a tiny coiled stainless steel wire filament using a micro-syringe, or by dipping the coil into the sample. After air evaporation of the solvent, the coil was inserted into the heated injection port of a portable GC-MS system where the analytes were desorbed. Injection using the coiled wire filament eliminated sample discrimination of high boiling point compounds, and minimized system contamination caused by sample matrix residues. The GC-MS contained a new resistively heated column bundle that allowed elution of low-volatility compounds in less than 4 min. Analyses of organochlorine pesticides, polycyclic aromatic hydrocarbons, polychlorinated biphenyl congeners, pyrethroid insecticides, phthalate esters, and n-alkanes in water and wastewater samples were accomplished for low ppb concentrations in less than 10 min total analysis time.
Low concentration natural methanol exists in most alcoholic beverages and usually causes no immediate health threat. Nevertheless, it is possible to have natural occurring methanol in beverages with concentration as high as 18 g/L of ethanol; or equivalent to 0.72% methanol in 40% ethanol, in alcohol (1). Current EU regulation limits naturally occurring methanol to below 10 g/L of ethanol; or equivalent to 0.4% methanol in 40% ethanol.
Diamond ATR has become one of the most commonly used FT-IR spectroscopy methods. However, the strong diamond lattice bands in the 2300–1900 cm-1 region make it difficult to measure the functional groups from nitriles, isocyanates, isothiocyanates, diimides, azides, and ketenes that would normally appear in that region. This applications note compares the sensitivity of a single-reflection ATR to multiple-reflection ATR for the nitrile functional group infrared transition.
The safety of the food that our children eat is a global concern. Regulations are in place that limit the maximum level of pesticides that can be present in food meant for children, and methods to detect levels well below those limits are needed to ensure the safety of the food supply. Combining the speed and separation efficiency of ultrahigh-pressure liquid hromatography (UHPLC) with the sensitivity and selectivity of triple-quadrupole mass spectrometry (MS)-MS results in a method that can deliver ultralow quantification of pesticides in baby food, with limits of detection more than an order of magnitude below the allowed maximum levels.
ICP-MS for the analysis of drinking water.
The authors discuss a noninvasive method for determining early indications of the rejection of a kidney transplant.
There is no doubt that funding for basic science in analytical atomic spectroscopy has waned over the years, and, in reality, barely exists today.
As has been previously discussed (1), FTIR spectroscopy is emerging as a technique that can be effectively used for applications and/or in locations that heretofore would be considered too demanding. The development of portable FTIRs, and more recently handheld FTIRs, is significant because it enables this powerful analytical technique to solve problems for a whole range of new applications, both in the laboratory, and out of the laboratory.
Gas chromatography combined with atmospheric-pressure chemical ionization (APCI) was used to analyze high-molecular-weight phthalates.
The increasing use of pesticide testing coupled with reductions in maximum permissible residue levels of pesticides in food have driven demand for fast, sensitive, and cost-effective analytical methods for high-throughput screening of multiclass pesticides in food. Detection of 510 pesticides at low parts-per-billion levels can be achieved within minutes using orbital trap technology. The high resolving power of these systems enables accurate mass confirmation of all compounds, including isobaric pesticides. This article will provide an overview of current legislation and illustrate how mass spectrometry instrumentation can enable fast and accurate pesticide screening.
Fast turnaround time is critical in the clinical testing environment. Here, fast liquid chromatography (LC) technologies were utilized for the comprehensive assay of commonly prescribed pain management drugs in under 2 min. The use of fast LC also provided significantly improved sensitivity. A mini-validation for these analytes in human urine was performed and acceptable values for accuracy, precision, linearity, lot-to-lot variability, and matrix effects were demonstrated for each analyte.
The authors discuss a noninvasive method for determining early indications of the rejection of a kidney transplant.
The onset of nanotechnology and targeted therapy methods for a number of pathologies has made it increasingly more difficult to image effectively in the medical field. With that being said, the inception of quantum dots and the improvements to optical filters has made this once daunting task a common practice.
A "Smart" Oxygen Cuvette has been developed by coating the inner surface of a plastic (PMMA) cuvette with sol-gel based oxygen-sensitive indicator material. This new oxygen sensing system monitors the dissolved oxygen in samples for biological and medical applications.
The total market for NIR was measured at about $470 million in 2019 and is expected to reach over $570 million by 2024.
A simple method for extraction and concentration of trace organic compounds found in water for gas chromatography-mass spectrometry (GC-MS) analysis was developed. The method used 25 and 45 mL glass vials with a 5-10 µm thick polymer coatings for extraction of analytes from 20 and 40 mL water samples, respectively. Analytes were subsequently transferred from the polymer coating into an organic solvent, which was reduced in volume to 200-400 µL for analysis. A 10-20 µL sample from the vial was transferred to a tiny coiled stainless steel wire filament using a micro-syringe, or by dipping the coil into the sample. After air evaporation of the solvent, the coil was inserted into the heated injection port of a portable GC-MS system where the analytes were desorbed. Injection using the coiled wire filament eliminated sample discrimination of high boiling point compounds, and minimized system contamination caused by sample matrix residues. The GC-MS contained a new resistively heated column bundle that allowed elution of low-volatility compounds in less than 4 min. Analyses of organochlorine pesticides, polycyclic aromatic hydrocarbons, polychlorinated biphenyl congeners, pyrethroid insecticides, phthalate esters, and n-alkanes in water and wastewater samples were accomplished for low ppb concentrations in less than 10 min total analysis time.
A drug-eluting stent (DES) is an expandable metal alloy framework placed into narrowed coronary arteries that slowly releases a drug coating to treat atherosclerosis. Production of DES is a labor-intensive batch process that requires very tight control. Fourier Transform Near-InfraRed spectroscopy (FT-NIR) is an efficient technique to perform accurate quantification of the different components in DES coating solutions.
This article presents an efficient analytical workflow for protein characterization using LC–MS.
A new time-of-flight mass spectrometer was evaluated for performing simultaneous metabolic stability measurement and metabolite identification with ultrahigh-pressure liquid chromatography. Six representative compounds (clomipramine, diclofenac, imipramine, haloperidol, verapamil, and midazolam) were incubated in rat liver microsomes at a more physiologically relevant substrate concentration (1 ?M). High-resolution full-scan and product-ion spectra were acquired in a single injection using generic methodology. Quantitative clearance of the parent was measured using the full-scan data. Major metabolites were identified using the accurate mass product ion spectra. High scanning speed allowed for a sufficient number of data points to be collected across the chromatographic peak for quantitative analysis. Sensitivity was sufficient for obtaining meaningful kinetics with a 1 ?M initial substrate concentration.
A better understanding of the micro- and nanostructures of cellulose fiber composition before and after various chemical treatments, together with the distribution of bleaching additives to the final paper composition, is essential for further improvements of paper properties. Confocal Raman imaging is a valuable tool for such studies, as it reveals not only optical information but also information regarding the 3D distribution of the chemical compounds in the submicrometer range. In the paper surface finishing process, additional surface roughness parameters can be measured by combining confocal Raman microscopy with atomic force microscopy. Such combined analytical microscopes allow a direct linking between high-resolution imaging and chemical identification of various species on a surface.
A single calibration curve run with staggered calibrants bracketing the unknowns is compared to running complete duplicate calibration curves, one at the beginning and one at the end of unknown sample analysis in an effort to accelerate discovery bioanalysis.