Analysis of the temperature of the photosphere and determine the temperature by students using CCD spectrometers.
The main limitations of quantification using MALDI imaging are discussed and the different approaches used for quantitative measurement in MSI are evaluated.
Crop development to improve yield or disease resistance has been explored for centuries and the technologies to measure these improvements have subsequently become complex. The use of transgenes in crop plants is a more technically advanced approach than traditional breeding and the success of this approach is best assessed using modern techniques that accurately quantify the desired traits. Here, we applied targeted liquid chromatography–mass spectrometry (LC–MS) using synthetic stable isotope–labeled peptides to identify and quantify the relative levels of transgenic to native protein.
This applications note compares the sensitivity of a single-reflection ATR to multiple-reflection ATR for the nitrile functional group infrared transition.
A brief historical overview of DMS, followed by a synopsis of the instrumentation, physics, and chemistry behind the separation principles
Under a suitable thermal oxidation regime, vegetable oils yield a mixture of volatile and semivolatile organics that exhibit very high antimicrobial activities against a variety of microbial species. Volatile and semivolatile products were characterized with GC–MS using electron ionization and chemical ionization. The thermal oxidation of vegetable oils resulted in the formation of an array of shortand medium-chain acids, aldehydes, and ketones that act synergistically to yield a potent antimicrobial disinfectant.
Hydrophilic interaction liquid chromatography (HILIC) and reversed-phase high performance liquid chromatography (HPLC) are complementary techniques in the separation of organic molecules with a broad band of polarity. Both separation variants can be operated easily with volatile and water-miscible solvents (for example, ammonium acetate aqueous solution and acetonitrile). Thus, a hyphenation of both liquid chromatographic techniques with atmospheric pressure ionization (API) and mass spectrometry (MS) seems to be a consequent step.
Gas chromatography–mass spectrometry (GC–MS) and liquid chromatography–mass spectrometry (LC–MS) techniques offer advantages in separating and confirming the identity of constituents in novel psychoactive substances.
Moxi™ X-ray source is calibrated to within ±250 V over all settings between 5 to 50 kV. This impressive accuracy and precision is achieved spectroscopically, by measuring an X-ray spectrum's bremsstrahlung edge and storing correction high voltage offset information on each source.
Fourier transform infrared (FT-IR) spectroscopic imaging is a highly versatile technique that can be applied to a wide range of systems. This article summarizes some of the recent efforts developing applications of FT-IR imaging for microfluidics. The main advantage of FT-IR imaging compared to traditional imaging methods is that it is a label-free imaging technique.
Accurate-mass approaches offer a significant advance over nominal-mass approaches in the arena of qualitative analysis, and some of the analytical approaches can now be conducted in a relatively routine manner.
Potassium bromate as an oxidizing agent in bread production is a staple, but it also poses health risks due to its classification as a carcinogen, necessitating careful monitoring of its residual levels. This application note reviews the spectrophotometric determination of potassium bromate concentration in bread based on the redox reaction between potassium bromate and promethazine in an acidic environment.
A rapid, accurate, and precise method for the quantification of trypsin inhibitor activity was evaluated. The method utilizes alpha hydroxyl acid capped oligo-lysines [hydroxy acid (Lys)n] or alpha hydroxyl acid capped oligo-lysines-methionine [hydroxy acid (Lys-Met)] as substrates. Hydrolysis of the oligopeptides yields unique chemical residues that were readily quantified with electrospray–mass spectrometry (ESI-MS). Accuracy and precision of the approach compared favorably with that of the standard test method.
Single-reaction-chamber (SRC) microwave digestion was used for the digestion of pharmaceutical samples before inductively coupled plasma–mass spectrometry (ICP-MS) analysis according to draft USP chapters <232> and <233>.
Lithium-based batteries are key for moving away from the combustion of fossil fuels at the point of use. ICP-OES and ICP-MS methods can measure trace-element impurities that may affect battery performance.
Crop development to improve yield or disease resistance has been explored for centuries and the technologies to measure these improvements have subsequently become complex. The use of transgenes in crop plants is a more technically advanced approach than traditional breeding and the success of this approach is best assessed using modern techniques that accurately quantify the desired traits. Here, we applied targeted liquid chromatography–mass spectrometry (LC–MS) using synthetic stable isotope–labeled peptides to identify and quantify the relative levels of transgenic to native protein.
A discovery-based, untargeted metabolomics analysis of hundreds of yeast metabolites under robust, controlled extraction conditions followed by identification is described.
Crop development to improve yield or disease resistance has been explored for centuries and the technologies to measure these improvements have subsequently become complex. The use of transgenes in crop plants is a more technically advanced approach than traditional breeding and the success of this approach is best assessed using modern techniques that accurately quantify the desired traits. Here, we applied targeted liquid chromatography–mass spectrometry (LC–MS) using synthetic stable isotope–labeled peptides to identify and quantify the relative levels of transgenic to native protein.
An update on the sample preparation and LC–MS-MS tools available for allergen detection, as well advantages of those techniques.
Nitrile rubber materials were studied using flash analytical pyrolysis-GC–MS to demonstrate that this technique is a good tool to identify the additives in nitrile rubber.
The authors discuss the use of serial coulometric flow cells coupled online with electrospray ionization mass spectrometry in predictive assays for absorption, distribution, metabolism, excretion, toxicity (ADME/Tox), and stability implemented at early stages of drug discovery.
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.
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 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.
In this article, the authors discuss the advantages of using a microbore UHPLC system coupled with a tandem mass spectrometer for the quantitation of in vivo pharmacokinetic samples.
Those fond of puns point out that mass spectrometry (MS) has become ever more focused in the last two decades, while at the same time offering ever more information. The dynamic market for biotherapeutics has driven a number of developments, particularly following the paradigm of well-characterized biopharmaceutical products (WCBP) (1,2). Partly as a result of automation and interfacing, those trained in biological or biochemical disciplines now use mass spectrometers routinely. This also means that the sorts of questions asked of MS have changed. Coping with biomolecule heterogeneity is a key challenge, not generally an issue for small molecule drugs. The data complexity means that mass information alone is insufficient. And at the submission stage, regulators are increasingly concerned about tertiary structure and conformation, something that was not previously an analytical requirement (2). Adding polyethylene glycol (PEG) to already heterogeneous molecules to prolong their half-lives in the body raises..
A big question in forensic science today is, “How do we best report uncertainty?” The answer to which approach is “best” turns out to be surprisingly complex, for many reasons.
Inductively coupled plasma optical emission spectrometry (ICP-OES) is the preferred technique for inorganic contaminant analysis of biodiesel, and PerkinElmer offers two technologies to support it. The Avio 220 Max and Avio 550 Max, combined with PerkinElmer's expertise, can help labs achieve accurate feedstock analysis demanded by today's market.
This article presents an efficient analytical workflow for protein characterization using LC–MS.