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Analytical Methods: Advancing Methods and Applications

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https://www.readbyqxmd.com/read/28286575/chiral-determination-of-3-4-methylenedioxypyrovalerone-enantiomers-in-rat-serum
#1
Michael D Hambuchen, Howard P Hendrickson, S Michael Owens
The emerging stimulant drug of abuse (3,4)-methylenedioxypyrovalerone [(R,S)-MDPV] is self-administered as a racemic mixture by intranasal, iv, oral, and smoking routes. The individual enantiomers are known to have widely different pharmacological effects, with (S)-MDPV showing much greater potency than (R)-MDPV in pharmacological testing. The goal of these studies was to develop and validate an analytical method for quantitation of (R)-MDPV, (S)-MDPV and (R,S)-MDPV in small volumes of rat serum using a chiral separation column and liquid chromatography-mass spectrometry...
January 28, 2017: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28217148/profiling-metals-in-cordyceps-sinensis-by-using-inductively-coupled-plasma-mass-spectrometry
#2
Xin Wei, Hankun Hu, Baogeng Zheng, Zikri Arslan, Hung-Chung Huang, Weidong Mao, Yi-Ming Liu
Cordyceps sinensis (C. sinensis) is a natural product that has diverse nutritional and medicinal values. Since the availability of natural C. sinensis becomes limited its authentication and quality control is of high significance. Herein we report on profiling of metals in C. sinensis by using inductively coupled plasma mass spectrometry (ICP-MS). The analysis reveals that C. sinensis contains a wide array of essential elements, including P, Mg, Zn, Cu, Fe, etc. Toxic metals detected are Cd, Pb, and As. In all five samples analyzed Pb contents are below 2...
January 28, 2017: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28458724/online-fluorescence-anisotropy-immunoassay-for-monitoring-insulin-secretion-from-islets-of-langerhans
#3
Adrian M Schrell, Nikita Mukhitov, Lian Yi, Joel E Adablah, Joshua Menezes, Michael G Roper
Insulin secretion from islets of Langerhans is a dynamic process that is essential for maintaining glucose homeostasis. The ability to measure dynamic changes in insulin levels upon glucose stimulation from single islets will allow testing of therapeutics and investigating mechanisms of defective secretion observed in metabolic diseases. Most approaches to date for measurement of rapid changes in insulin levels rely on separations, making the assays difficult to translate to non-specialist laboratories. To enable rapid measurements of secretion dynamics from a single islet in a manner that will be more suitable for transfer to non-specialized laboratories, a microfluidic online fluorescence anisotropy immunoassay was developed...
January 7, 2017: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28194233/checkpoints-for-preliminary-identification-of-small-molecules-found-enriched-in-autophagosomes-and-activated-mast-cell-secretions-analyzed-by-comparative-uplc-ms-e
#4
Chad P Satori, Marzieh Ramezani, Joseph S Koopmeiners, Audrey F Meyer, Jose A Rodriguez-Navarro, Michelle M Kuhns, Thane H Taylor, Christy L Haynes, Joseph J Dalluge, Edgar A Arriaga
We report the use of ultra high performance liquid chromatography (UPLC) coupled with acquisition of low- and high-collision energy mass spectra (MS(e)) to explore small molecule compositions that are unique to either enriched-autophagosomes or secretions of chemically activated murine mast cells. Starting with thousands of features, each defined by a chromatographic retention time, m/z values and ion intensities, manual examination of the extracted ion chromatograms (XIC) of chemometrically selected features was essential to eliminate false positives, occurring at rates of 33, 14 and 37% in samples of three biological systems...
2017: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28446924/differential-leukocyte-counting-via-fluorescent-detection-and-image-processing-on-a-centrifugal-microfluidic-platform
#5
Max L Balter, Alvin I Chen, C Amara Colinco, Alexander Gorshkov, Brian Bixon, Vincent Martin, Alexander Fromholtz, Timothy J Maguire, Martin L Yarmush
Centrifugal microfluidics has received much attention in the last decade for the automation of blood testing at the point-of-care, specifically for the detection of chemistries, proteins, and nucleic acids. However, the detection of common blood cells on-disc, particularly leukocytes, remains a challenge. In this paper, we present two analytical methods for enumerating leukocytes on a centrifugal platform using a custom-built fluorescent microscope, acridine orange nuclear staining, and image processing techniques...
December 21, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28496521/on-chip-fluorescent-labeling-using-reversed-phase-monoliths-and-microchip-electrophoretic-separations-of-selected-preterm-birth-biomarkers
#6
Mukul Sonker, Rui Yang, Vishal Sahore, Suresh Kumar, Adam T Woolley
On-chip preconcentration, purification, and fluorescent labeling are desirable sample preparation steps to achieve complete automation in integrated microfluidic systems. In this work, we developed electrokinetically operated microfluidic devices for solid-phase extraction and fluorescent labeling of preterm birth (PTB) biomarkers. Reversed-phase monoliths based on different acrylate monomers were photopolymerized in cyclic olefin copolymer microdevices and studied for the selective retention and elution of a fluorescent dye and PTB biomarkers...
November 21, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/27812369/the-performance-of-single-and-multi-collector-icp-ms-instruments-for-fast-and-reliable-34-s-32-s-isotope-ratio-measurements
#7
Ondrej Hanousek, Marion Brunner, Daniel Pröfrock, Johanna Irrgeher, Thomas Prohaska
The performance and validation characteristics of different single collector inductively coupled plasma mass spectrometers based on different technical principles (ICP-SFMS, ICP-QMS in reaction and collision modes, and ICP-MS/MS) were evaluated in comparison to the performance of MC ICP-MS for fast and reliable S isotope ratio measurements. The validation included the determination of LOD, BEC, measurement repeatability, within-lab reproducibility and deviation from certified values as well as a study on instrumental isotopic fractionation (IIF) and the calculation of the combined standard measurement uncertainty...
November 14, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28392839/recent-advances-in-microscale-western-blotting
#8
Brittany J Sanders, Daniel C Kim, Robert C Dunn
Western blotting is a ubiquitous tool used extensively in the clinical and research settings to identify proteins and characterize their levels. It has rapidly become a mainstay in research laboratories due to its specificity, low cost, and ease of use. The specificity arises from the orthogonal processes used to identify proteins. Samples are first separated based on size and then probed with antibodies specific for the protein of interest. This confirmatory approach helps avoid pitfalls associated with antibody cross-reactivity and specificity issues...
October 21, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28127406/multiplexed-detection-of-pathogen-specific-dna-using-engineered-zinc-finger-proteins-without-target-amplification
#9
Moon-Soo Kim, Juhwa Kim
Multiplexed detection of pathogen-specific DNA sequences in a simple and reliable way is in great demand for clinical and biomedical applications. However, there is still a lack of available DNA detection methods that are simple and pathogen-selective for point-of-care (POC) testing. Here, we report a novel zinc finger protein (ZFP)-based chemiluminescent method for direct detection of pathogenic double-stranded DNA (dsDNA) in a multiplexed platform. ZFPs are custom-designed to identify unique pathogenic DNA sequences...
October 7, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/27617038/3d-printed-microfluidic-devices-fabrication-advantages-and-limitations-a-mini-review
#10
Chengpeng Chen, Benjamin T Mehl, Akash S Munshi, Alexandra D Townsend, Dana M Spence, R Scott Martin
A mini-review with 79 references. In this review, the most recent trends in 3D-printed microfluidic devices are discussed. In addition, a focus is given to the fabrication aspects of these devices, with the supplemental information containing detailed instructions for designing a variety of structures including: a microfluidic channel, threads to accommodate commercial fluidic fittings, a flow splitter; a well plate, a mold for PDMS channel casting; and how to combine multiple designs into a single device. The advantages and limitations of 3D-printed microfluidic devices are thoroughly discussed, as are some future directions for the field...
August 21, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28018490/detecting-levels-of-polyquaternium-10-pq-10-via-potentiometric-titration-with-dextran-sulphate-and-monitoring-the-equivalence-point-with-a-polymeric-membrane-based-polyion-sensor
#11
Stephen A Ferguson, Xuewei Wang, Mark E Meyerhoff
Polymeric quaternary ammonium salts (polyquaterniums) have found increasing use in industrial and cosmetic applications in recent years. More specifically, polyquaternium-10 (PQ-10) is routinely used in cosmetic applications as a conditioner in personal care product formulations. Herein, we demonstrate the use of potentiometric polyion-sensitive polymeric membrane-based electrodes to quantify PQ-10 levels. Mixtures containing both PQ-10 and sodium lauryl sulfate (SLS) are used as model samples to illustrate this new method...
August 7, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/27574530/detection-and-identification-of-sugar-alcohol-sweeteners-by-ion-mobility-spectrometry
#12
Christopher A Browne, Thomas P Forbes, Edward Sisco
The rapid and sensitive detection of sugar alcohol sweeteners was demonstrated using ion mobility spectrometry (IMS). IMS provides a valuable alternative in sensitivity, cost, and analysis speed between the lengthy gold-standard liquid chromatography-mass spectrometry (LC-MS) technique and rapid point-of-measurement disposable colorimetric sensors, for the Food and Nutrition industry's quality control and other "foodomics" area needs. The IMS response, characteristic signatures, and limits of detection for erythritol, pentaerythritol, xylitol, inositol, sorbitol, mannitol, and maltitol were evaluated using precise inkjet printed samples...
July 28, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28090219/integrated-microfluidic-aptasensor-for-mass-spectrometric-detection-of-vasopressin-in-human-plasma-ultrafiltrate
#13
J Yang, J Zhu, R Pei, J A Oliver, D W Landry, M N Stojanovic, Q Lin
We present a microfluidic aptamer-based biosensor for detection of low-molecular-weight biomarkers in patient samples. Using a microfluidic device that integrates aptamer-based specific analyte extraction, isocratic elution, and detection by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, we demonstrate rapid, sensitive and label-free detection of arginine vasopressin (AVP) in human plasma ultrafiltrate. AVP molecules in complex matrices are specifically captured by an aptamer that is immobilized on microbeads via affinity binding in a microchamber...
July 14, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/27818712/integrated-electrodes-and-electrospray-emitter-for-polymer-microfluidic-nanospray-ms-interface
#14
Anna V Forzano, Vedada Becirovic, R Scott Martin, James L Edwards
Interfacing of microfluidic devices to mass spectrometry has challenges including dilution from sheath liquid junctions, fragile electrodes, and excessive dead volumes which prevent optimum performance and common use. The goal of this work is to develop a stable nanospray chip-MS interface that contains easily integrated electrodes and an embedded capillary emitter to mitigate current chip-MS problems. This system uses a hybrid polystyrene-poly(dimethylsiloxane) (PS-PDMS) microfluidic platform with an embedded electrode and integrated capillary emitter used as the nanospray interface...
July 7, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/27695531/quantitative-determination-of-betamethasone-sodium-phosphate-and-betamethasone-dipropionate-in-human-plasma-by-uplc-ms-ms-and-a-bioequivalence-study
#15
Man-Yun Chen, Yong-Jun Tang, Yi-Cheng Wang, Chong-Zhi Wang, Chun-Su Yuan, Yao Chen, Zhi-Rong Tan, Wei-Hua Huang, Hong-Hao Zhou
The compound medicine of betamethasone sodium phosphate (BSP) and betamethasone dipropionate (BDP) is widely used for diverse glucocorticoid-sensitive acute and chronic diseases such as asthma, rheumatoid arthritis and systemic lupus erythematosus. It will be useful and beneficial to validate sensitive method for the determination of BSP, BDP and their metabolites for their pharmacokinetic study. Hereby, an ultra-high pressure liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) has been validated for the determination of BSP, BDP and their metabolites betamethasone (BOH), betamethasone 17-monodipropionate (B17P) and betamethasone 21-monodipropionate (B21P) in human plasma...
May 7, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/27482292/a-label-free-sirtuin-1-assay-based-on-droplet-electrospray-ionization-mass-spectrometry
#16
Shuwen Sun, Benjamin C Buer, E Neil G Marsh, Robert T Kennedy
Sirtuin 1(SIRT1) is a NAD(+)-dependent deacetylase which has been implicated in age-related diseases such as cancer, Alzheimer's disease, type 2 diabetes, and vascular diseases. SIRT1 modulators are of interest for their potential therapeutic use and potential as chemical probes to study the role of SIRT1. Fluorescence-based assays used to identify SIRT1 activators have been shown to have artifacts related to the fluorophore substrates used in the assays. Such problems highlight the potential utility of a label-free high throughput screening (HTS) strategy...
May 7, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/27990179/analysis-of-urine-oral-fluid-and-fingerprints-by-liquid-extraction-surface-analysis-coupled-to-high-resolution-ms-and-ms-ms-opportunities-for-forensic-and-biomedical-science
#17
Melanie Bailey, Elizabeth C Randall, Catia Costa, Tara L Salter, Alan M Race, Marcel de Puit, Mattijs Koeberg, Mark Baumert, Josephine Bunch
Liquid Extraction Surface Analysis (LESA) is a new, high throughput tool for ambient mass spectrometry. A solvent droplet is deposited from a pipette tip onto a surface and maintains contact with both the surface and the pipette tip for a few seconds before being re-aspirated. The technique is particularly suited to the analysis of trace materials on surfaces due to its high sensitivity and low volume of sample removal. In this work, we assess the suitability of LESA for obtaining detailed chemical profiles of fingerprints, oral fluid and urine, which may be used in future for rapid medical diagnostics or metabolomics studies...
April 28, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/27688816/a-capillary-electrophoresis-electrospray-ionization-mass-spectrometry-method-using-a-borate-background-electrolyte-for-the-fingerprinting-analysis-of-flavonoids-in-ginkgo-biloba-herbal-supplements
#18
Ryan T Johnson, Craig E Lunte
A laboratory-built sheath liquid capillary electrophoresis-mass spectrometry interface was used to develop a qualitative method for fingerprinting analysis of 14 structurally similar flavones, flavonols, flavonones, and several representative glycosides in plant samples. The migration order of the flavonoids was dependent on a the number of hydroxyl groups present on the flavonoid B-ring, extent of conjugation, number of glycosidic functionalities, and ability of the flavonoid to form stable borate complexes with the background electrolyte...
April 28, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/27909462/difluoroboron-%C3%AE-diketonate-materials-with-long-lived-phosphorescence-enable-lifetime-based-oxygen-imaging-with-a-portable-cost-effective-camera
#19
Alexander S Mathew, Christopher A DeRosa, James N Demas, Cassandra L Fraser
Lifetime-based oxygen imaging is useful in many biological applications but instrumentation can be stationary, expensive, and complex. Herein, we present a portable, cost effective, simple alternative with high spatiotemporal resolution that uses a complementary metal oxide silicon (CMOS) camera to measure oxygen sensitive lifetimes on the millisecond scale. We demonstrate its compatibility with difluoroboron β-diketonate poly(lactic acid) (BF2bdkPLA) polymers which are nontoxic and exhibit long-lived oxygen sensitive phosphorescence...
April 21, 2016: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/27335585/detection-of-low-molecular-weight-adulterants-in-beverages-by-direct-analysis-in-real-time-mass-spectrometry
#20
Edward Sisco, Jeffrey Dake
Direct Analysis in Real Time Mass Spectrometry (DART-MS) has been used to detect the presence of non-narcotic adulterants in beverages. The non-narcotic adulterants that were examined in this work incorporated a number low molecular weight alcohols, acetone, ammonium hydroxide, and sodium hypochlorite. Analysis of the adulterants was completed by pipetting 1 µL deposits onto glass microcapillaries along with an appropriate dopant species followed by introduction into the DART gas stream. It was found that detection of these compounds in the complex matrices of common beverages (soda, energy drinks, etc...
April 14, 2016: Analytical Methods: Advancing Methods and Applications
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