April 12th 2024
Here are the top five articles that the editors of Spectroscopy published this week.
Appropriate Use of Mass Spectrometry in Clinical and Metabolic Research
March 1st 2017Using examples from our analysis of L-carnitine and acyl-L-carnitines, we give specific guidance for the use of mass spectrometry in quantitative analysis, as applied to clinical research and clinical pharmacology. We focus on quantitative accuracy and analytical selectivity as keys to successful implementation of mass spectrometric methods in clinical applications
Quantitation of Albumin and Creatinine in Urine by MALDI-TOF Mass Spectrometry
October 1st 2016Chronic kidney disease or kidney complication resulting from another systematic disorder can impact the organ’s blood filtering capability resulting in the passage of blood-born proteins through the kidneys and into urine. Clinical analyses for blood proteins in urine are performed to assess proper kidney function or to monitor a diagnosed disorder. Serum albumin is a common target in these clinical assays and detection of elevated SA levels in urine is termed Albuminuria. Because of normal variability in urine content and volume multiple measurements are often made in comparison to creatitine levels within the same urine sample and reported as a ratio (ACR). Demonstrated here is a novel means for quantifying albumin and creatinine directly from the same urine sample using MALDI-TOF mass spectrometry. Standard addition of albumin and deuterated creatinine (d3) into control urine produced a linear and quantitative response (R2 = 0.99 and 0.98) and is used to quantify both analytes across their clinically relevant ranges. This MS-based method represents a simple, fast, attractive alternative to currently clinical methods.
Nontargeted Metabolite Profiling in Next-Generation Plant Breeding: A Case Study in Malting Barley
October 1st 2016The power of nontargeted metabolite profiling is illustrated in a study focused on the determination of molecular markers in malting barley that are predictive of desirable malting quality for brewing applications. The metabolite extraction, detection, and analysis methods are highthroughput and reproducible, and therefore, this approach represents a practical addition to the plant breeder’s molecular toolbox.
Simultaneous Quantitation of Buprenorphine and Its Metabolites Using LC–MS
July 1st 2016An LC-MS method has been developed for simultaneous quantification of buprenorphine and its three metabolites, namely norbuprenorphine, buprenorphine glucuronide, and norbuprenorphine glucuronide Chromatographic separation was achieved on a C18 column with a gradient of acetonitrile and ammonium acetate buffer (25 mM, pH 6.6). The method run time was 7.5 min. Quantification was performed by selected ion monitoring of [M+H]+ ions of norbuprenorphine glucuronide (590), norbuprenorphine (414), buprenorphine glucuronide (644) and buprenorphine (468). Naloxone (328) (328ng/mL) was used as an internal standard. The samples were processed by protein precipitation and extraction recovery was ≥95% with minimal observed matrix effects (
Sensitive, Rapid Estimation of Moxidectin in Cattle Hair by LC–MS-MS
July 1st 2016Moxidectin formulations help to reduce hair loss and irritation due to parasite worms in animals. So Estimation of Moxidectin in hair is important to evaluate therapeutic levels, distribution & accumulation, however estimation is also useful to evaluate harm to birds when they eat animal hair. Hence Moxidectin estimation is required for pharmacokinetic as well as environmental exposure study. Objective of the present work is to develop a rapid, selective method for the estimation of Moxidectin in Cattle Hair by LC-MS/MS. Oxcarbazepine used as a internal standard. Moxidectin extracted from cattle hair by liquid-liquid extraction using Sorenson’s Buffer as digestion solvent for incubation & methyl tert-butyl ether as an extraction solvent. Detection was performed over the range 0.026 to 1.000 ng/mG using MRM in positive polarity at unit resolution under turbo ion spray whereas separation was achieved on Kinetex 100 x 4.6 mm, 5u EVO C18 100A column with Methanol : 10mM Amonium formate pumped as gradient flow with 4.50min run time. Q1 is 640.45 whereas Q3 is sum of 528.50 and 498.50. Validation parameters shown reliable results. Method is applied for the estimation of Moxidectin in cattle Hair.
A newly discovered method is described for generating gas-phase ions from volatile and nonvolatile compounds. The method, matrix-assisted ionization (MAI), is both simple and sensitive, requiring only the vacuum inherent with all mass spectrometers and a suitable matrix, eliminating the need for lasers, electric fields, nebulizing gas, and even heaters to generate gas-phase ions. MAI is applicable for the direct analysis of drugs from biological fluids and tissue without prior purification. By placing matrix only on a specific surface area of interest and exposure to the vacuum of the mass spectrometer, ions are observed from compounds within the targeted surface area of tissue exposed to the matrix solution, thus allowing rapid and simple interrogation of “features of interest.” The limit of detection for drug standards is low attomoles and clean full mass range mass spectra are obtained from low femtomoles of the drug.
The purpose of this study was the development of various analytical MS methods to investigate the chemical composition of e-liquids used in electronic cigarettes and characterize their quality. Low-quality nicotine (the main active compound), glycerol, propylene glycol (solvents), or flavors could greatly increase the toxicity. The search of alkaloid contaminants of nicotine was performed by LC–MS-MS after a deep study of fragmentation pathways by high resolution ESI-MS. A fully validated method for quantitation of organic polar impurities such as cotinine, anabasine, myosmine, nornicotine, and N-nitroso-nornicotine and nicotine itself was developed using MS coupled to UHPLC. To evaluate organic volatile toxicants, headspace from e-cigarette refill liquids was sampled by SPME to perform GC–MS analysis. Finally, heavy metal residues as inorganic toxicants were determined by ICP-MS after simple dilution. A number of cases of contamination by metals (mainly arsenic) was detected.
Review of New Spectroscopic Instrumentation 2016
May 1st 2016Our annual review of products introduced at Pittcon or during the previous year, broken down by the following categories: accessories, atomic spectroscopy, components, imaging, mass spectrometry, mid-IR, NIR, NMR, Raman, software, UV-vis, and X-ray.
A Rapid, Selective, and Sensitive Method for the Analysis of Naltrexone and 6β-Naltrexol in Urine
March 1st 2016Naltrexone (Depade, Re Via, Trexan) is a potent narcotic antagonist structurally similar to oxymorphone and naloxone. It blocks the subjective effects of heroin and other opiates and is primarily used in the management of opioid dependence and alcohol dependence. While conjugated 6β-naltrexol is the major urinary metabolite in man, conjugated naltrexone and free 6β-naltrexol are also major urinary species. To assist with monitoring substance abuse patients who are prescribed naltrexone, a rapid, selective, and sensitive LC–MS-MS method was developed to analyze for both naltrexone and 6β-naltrexol post-enzymatic hydrolysis. The validation of this method and some representative patient data are discussed in this report.
Combining Raman Imaging, Mass Spectrometry Imaging, and AFM
December 1st 2015Imaging techniques using vibrational spectroscopy, mass spectrometry (MS), and atomic force microscopy have all been advancing and gaining momentum in recent years. There is great potential power in these imaging techniques, particularly in the biomedical field. Thomas Bocklitz of at the Friedrich-Schiller-University Jena is working to better harness the power of these techniques by combining them.
Nowadays, biotherapeutic proteins are available in different formats such as fusion proteins, monoclonal antibodies, or antibody-drug conjugates. The complexity of these molecules requires advanced and comprehensive characterization to guarantee their potency and safety. This work provides an overview of a methodology using an innovative capillary electrophoresis-tandem mass spectrometry coupling (CE-MS-MS) for the characterization of biologics primary structure. This method was applied to perform biosimilarity assessment between two mAbs, distinguishing minor differences like a sole amino acid substitution. Such a level of characterization is permitted by cumulating the specificities of both CE and high-resolution tandem MS using a sheathless interface, therefore renewing the interest for this type of coupling.
Combining Thermal Desorption GC and TOF-MS for the Determination of Melon VOC Profiles
October 1st 2015The quality and safety of ready-to-eat packaged foods-such as salads-is very difficult for consumers and suppliers to judge, and improving this situation is the focus of a Europe-wide research project. Part of the project is devoted to the development of better methods to detect and analyze the volatile organic compounds released from relevant food types, in an effort to identify biomarkers for quality and microbial contamination. This article examines one important food (melon) and shows how a method based on thermal desorption (TD) with gas chromatography-time-of-flight-mass spectrometry (GC–TOF-MS) can elucidate how key volatiles vary with time of storage and with the size of the melon pieces. The article highlights how such analytical information will be of value in efforts to improve the quality and safety of ready-to-eat foods.
MS Detection of Waste in Public Swimming Facilities
October 1st 2015There is often insufficient prevention to ensure safe swimming environments. Recreation water illness (RWI), most commonly in the form of digestional track illness as well as skin, ear, and respiratory infections, are often caused by water contamination from human waste. Stercobilin is a very stable and suitable chemical biomarker of human waste that has the potential to be used for waste monitoring in public swimming facilities. Using solid phase extraction (SPE) techniques paired with high-resolution mass spectrometry (HRMS), we have developed a robust method used for swimming pool water monitoring to create safer swimming environments.
Mass Spectrometry in the Clinical Laboratory—Challenges for Quality Assurance
July 1st 2015Beyond the long-established, optical standard techniques of photometry and immunoassay, LC-API-MS-MS has opened new horizons for clinical pathology. This is related to biomedical research and standardization as well as to routine diagnostic testing. It can be expected that the latter field will see important growth, including the introduction of automated MS-based analyzer systems. This will shift the application of mass spectrometric tests from a few specialized laboratories to many standard clinical laboratories with a lower level of analytical expertise.
Unraveling the Links Between Diet and Human Health Using LC–MS-MS
October 1st 2014We recently spoke to Gary Duncan and Wendy Russell of the Rowett Institute of Nutrition & Health in Aberdeen, Scotland, about the significance of phytochemical bioavailability to human health and the important role of liquid chromatography linked to tandem mass spectrometry (LC–MS-MS) in their research.