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You searched for: Journal name Analytical chemistry Remove constraint Journal name: Analytical chemistry Publication Year 2015 Remove constraint Publication Year: 2015 Subject term gases Remove constraint Subject term: gases
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1. Analysis of a Common Cold Virus and Its Subviral Particles by Gas-Phase Electrophoretic Mobility Molecular Analysis and Native Mass Spectrometry

Author:
Weiss Victor U.; Bereszcazk Jessica Z.; Havlik Marlene; Kallinger Peter; Gösler Irene; Kumar Mohit; Blaas Dieter; Marchetti-Deschmann Martina; Heck Albert J. R.; Szymanski Wladyslaw W.; Allmaier Günter
Source:
Analytical chemistry 2015 v.87 no.17 pp. 8709-8717
ISSN:
1520-6882
Subject:
Human rhinovirus; capsid; common cold; desorption; electrophoresis; electrospraying; encapsulation; gases; genome; ionization; mass spectrometry; molecular weight; particle size; proteins; serotypes; virion; viruses
Abstract:
... Gas-phase electrophoretic mobility molecular analysis (GEMMA) separates nanometer-sized, single-charged particles according to their electrophoretic mobility (EM) diameter after transition to the gas-phase via a nano electrospray process. Electrospraying as a soft desorption/ionization technique preserves noncovalent biospecific interactions. GEMMA is therefore well suited for the analysis of inta ...
DOI:
10.1021/acs.analchem.5b01450
PubMed:
26221912
PubMed Central:
PMC4558612

2. Cavity-Enhanced Raman Spectroscopy of Natural Gas with Optical Feedback cw-Diode Lasers

Author:
Hippler Michael
Source:
Analytical chemistry 2015 v.87 no.15 pp. 7803-7809
ISSN:
1520-6882
Subject:
Raman spectroscopy; alkanes; cameras; carbon dioxide; detection limit; gases; hydrogen; hydrogen sulfide; lasers; monitoring; natural gas; nitrogen; spectral analysis
Abstract:
... We report on improvements made on our previously introduced technique of cavity-enhanced Raman spectroscopy (CERS) with optical feedback cw-diode lasers in the gas phase, including a new mode-matching procedure which keeps the laser in resonance with the optical cavity without inducing long-term frequency shifts of the laser, and using a new CCD camera with improved noise performance. With 10 mW o ...
DOI:
10.1021/acs.analchem.5b01462

3. Collision Induced Unfolding of Intact Antibodies: Rapid Characterization of Disulfide Bonding Patterns, Glycosylation, and Structures

Author:
Tian Yuwei; Han Linjie; Buckner Adam C.; Ruotolo Brandon T.
Source:
Analytical chemistry 2015 v.87 no.22 pp. 11509-11515
ISSN:
1520-6882
Subject:
adverse effects; drugs; energy; gases; glycosylation; heat; ions; monoclonal antibodies; proteins; quality control; spectroscopy; therapeutics
Abstract:
... Monoclonal antibodies (mAbs) are among the fastest growing class of therapeutics due to their high specificity and low incidence of side effects. Unlike most drugs, mAbs are complex macromolecules (∼150 kDa), leading to a host of quality control and characterization challenges inherent in their development. Recently, we introduced a new approach for the analysis of the intact proteins based on ion ...
DOI:
10.1021/acs.analchem.5b03291

4. Combined Use of Ion Mobility and Collision-Induced Dissociation To Investigate the Opening of Disulfide Bridges by Electron-Transfer Dissociation in Peptides Bearing Two Disulfide Bonds

Author:
Massonnet Philippe; Upert Gregory; Smargiasso Nicolas; Gilles Nicolas; Quinton Loïc; De Pauw Edwin
Source:
Analytical chemistry 2015 v.87 no.10 pp. 5240-5246
ISSN:
1520-6882
Subject:
alkylation; chemical reduction; cysteine; dissociation; disulfide bonds; electron transfer; gases; peptides; post-translational modification; protein conformation; proteins; sulfides
Abstract:
... Disulfide bonds are post-translational modifications (PTMs) often found in peptides and proteins. They increase their stability toward enzymatic degradations and provide the structure and (consequently) the activity of such folded proteins. The characterization of disulfide patterns, i.e., the cysteine connectivity, is crucial to achieve a global picture of the active conformation of the protein o ...
DOI:
10.1021/acs.analchem.5b00245

5. Competitive Volumetric Bar-Chart Chip with Real-Time Internal Control for Point-of-Care Diagnostics

Author:
Li Ying; Xuan Jie; Xia Tom; Han Xin; Song Yujun; Cao Zheng; Jiang Xin; Guo Yi; Wang Ping; Qin Lidong
Source:
Analytical chemistry 2015 v.87 no.7 pp. 3771-3777
ISSN:
1520-6882
Subject:
biomarkers; diagnostic techniques; environmental factors; enzyme-linked immunosorbent assay; gases; human chorionic gonadotropin; illicit drugs; neoplasm cells; neoplasms; patients; pregnancy
Abstract:
... Point-of-care (POC) testing has become widely used in clinical analysis because of its speed and portability; however, POC tools, such as lateral flow assays, suffer from low specificity, unclear readouts, and susceptibility to environmental and user errors. Herein, we report an ELISA-based competitive volumetric bar-chart chip (CV-chip) that eliminates these limitations. The CV-chip displays the ...
DOI:
10.1021/ac504301y
PubMed:
25751686
PubMed Central:
PMC4631400

6. Direct Quantification of Chemical Warfare Agents and Related Compounds at Low ppt Levels: Comparing Active Capillary Dielectric Barrier Discharge Plasma Ionization and Secondary Electrospray Ionization Mass Spectrometry

Author:
Wolf Jan-Christoph; Schaer Martin; Siegenthaler Peter; Zenobi Renato
Source:
Analytical chemistry 2015 v.87 no.1 pp. 723-729
ISSN:
1520-6882
Subject:
detection limit; electrospray ionization mass spectrometry; evaporation; gases; hydrolysis; ionization; monitoring; nerve agents; toxicity
Abstract:
... A novel active capillary dielectric barrier discharge plasma ionization (DBDI) technique for mass spectrometry is applied to the direct detection of 13 chemical warfare related compounds, including sarin, and compared to secondary electrospray ionization (SESI) in terms of selectivity and sensitivity. The investigated compounds include an intact chemical warfare agent and structurally related mole ...
DOI:
10.1021/ac5035874

7. Distinguishing Loss of Structure from Subunit Dissociation for Protein Complexes with Variable Temperature Ion Mobility Mass Spectrometry

Author:
Pacholarz Kamila J.; Barran Perdita E.
Source:
Analytical chemistry 2015 v.87 no.12 pp. 6271-6279
ISSN:
1520-6882
Subject:
ambient temperature; amyloid; avidin; blood serum; concanavalin A; data collection; differential scanning calorimetry; dissociation; gases; humans; mass spectrometry; melting; melting point; prealbumin; protein unfolding; thermal stability
Abstract:
... The thermal stability and strength of interactions in proteins are commonly measured using isothermal calorimetry and differential scanning calorimetry providing a measurement that averages over structural transitions that occur as the proteins melt and dissociate. Here, we apply variable temperature ion mobility mass spectrometry (VT-IM-MS) to study the effect of temperature on the stability and ...
DOI:
10.1021/acs.analchem.5b01063

8. Effect of Metals in Biomimetic Dimetal Complexes on Affinity and Gas-Phase Protection of Phosphate Esters

Author:
Svane Simon; Jørgensen Thomas J. D.; McKenzie Christine J.; Kjeldsen Frank
Source:
Analytical chemistry 2015 v.87 no.14 pp. 7060-7068
ISSN:
1520-6882
Subject:
biomimetics; calorimetry; copper; dissociation; esters; gases; iron; phosphates; tandem mass spectrometry; titration; zinc
Abstract:
... Although the biomimetic dimetal complex [LGa₂(OH)₂(H₂O)₂]³⁺ [L = 2,6-bis((N,N′-bis(2-picolyl)amino)methyl)-4-tertbutylphenolate] provides efficient protection against phosphate loss in phosphopeptides upon collision-induced dissociation tandem mass spectrometry (CID MS/MS), the underlying mechanism remains unknown. Here, we explored the mechanism in detail and investigated the selective binding to ...
DOI:
10.1021/acs.analchem.5b00257

9. Fast and Highly Sensitive Fiber-Enhanced Raman Spectroscopic Monitoring of Molecular H2 and CH4 for Point-of-Care Diagnosis of Malabsorption Disorders in Exhaled Human Breath

Author:
Hanf Stefan; Bögözi Timea; Keiner Robert; Frosch Torsten; Popp Jürgen
Source:
Analytical chemistry 2015 v.87 no.2 pp. 982-988
ISSN:
1520-6882
Subject:
Raman spectroscopy; biomarkers; breath tests; carbon dioxide; detection limit; fermentation; fructose; gases; humans; hydrogen; lactose; malabsorption; metabolic diseases; methane; monitoring; nitrogen; obesity; oxygen; photonics; silica
Abstract:
... Breath gas analysis is a novel powerful technique for noninvasive, early-stage diagnosis of metabolic disorders or diseases. Molecular hydrogen and methane are biomarkers for colonic fermentation, because of malabsorption of oligosaccharides (e.g., lactose or fructose) and for small intestinal bacterial overgrowth. Recently, the presence of these gases in exhaled breath was also correlated with ob ...
DOI:
10.1021/ac503450y

10. Hyphenation of Thermal Analysis to Ultrahigh-Resolution Mass Spectrometry (Fourier Transform Ion Cyclotron Resonance Mass Spectrometry) Using Atmospheric Pressure Chemical Ionization For Studying Composition and Thermal Degradation of Complex Materials

Author:
Rüger Christopher P.; Miersch Toni; Schwemer Theo; Sklorz Martin; Zimmermann Ralf
Source:
Analytical chemistry 2015 v.87 no.13 pp. 6493-6499
ISSN:
1520-6882
Subject:
Betula; Fagus; Picea; abietic acid; aldehydes; alkanes; atmospheric pressure; biomass; elemental composition; fuel oils; gases; ionization; lignocellulose; mass spectrometry; pellets; petroleum; polar compounds; pyrolysis; softwood; spectrometers; temperature; thermal analysis; thermal properties
Abstract:
... In this study, the hyphenation of a thermobalance to an ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometer (UHR FTICR MS) is presented. Atmospheric pressure chemical ionization (APCI) is used for efficient ionization. The evolved gas analysis (EGA), using high-resolution mass spectrometry allows the time-resolved molecular characterization of thermally induced process ...
DOI:
10.1021/acs.analchem.5b00785

11. Interactions of Hemoglobin and Myoglobin with Their Ligands CN–, CO, and O2 Monitored by Electrospray Ionization-Mass Spectrometry

Author:
Sowole Modupeola A.; Vuong Stephanie; Konermann Lars
Source:
Analytical chemistry 2015 v.87 no.19 pp. 9538-9545
ISSN:
1520-6882
Subject:
carbon monoxide; cyanides; dissociation; electrospray ionization mass spectrometry; gases; hemoglobin; ions; ligands; myoglobin; oxidation; oxygen; spectral analysis
Abstract:
... Electrospray ionization (ESI)-mass spectrometry (MS) can provide information on protein–ligand interactions via detection of the corresponding complexes as gaseous ions. Unfortunately, some systems are prone to dissociation upon transfer into the gas phase. The reversible oxygen binding to hemoglobin (Hb) has been extensively studied in solution using a wide range of biophysical techniques. In add ...
DOI:
10.1021/acs.analchem.5b02506

12. Surface-Bubble-Modulated Liquid Chromatography: A New Approach for Manipulation of Chromatographic Retention and Investigation of Solute Distribution at Water/Hydrophobic Interfaces

Author:
Nakamura Keisuke; Nakamura Hiroki; Saito Shingo; Shibukawa Masami
Source:
Analytical chemistry 2015 v.87 no.2 pp. 1180-1187
ISSN:
1520-6882
Subject:
aqueous solutions; gases; hydrophobicity; liquid chromatography; organic compounds; silica; solutes; surface water
Abstract:
... In this paper, we present a new chromatographic method termed surface-bubble-modulated liquid chromatography (SBMLC), that has a hybrid separation medium incorporated with surface nanobubbles. Nanobubbles or nanoscale gas phases can be fixed at the interface between water and a hydrophobic material by delivering water into a dry column packed with a nanoporous material. The incorporation of a gas ...
DOI:
10.1021/ac503802q

13. Amphipols Outperform Dodecylmaltoside Micelles in Stabilizing Membrane Protein Structure in the Gas Phase

Author:
Calabrese Antonio N.; Watkinson Thomas G.; Henderson Peter J. F.; Radford Sheena E.; Ashcroft Alison E.
Source:
Analytical chemistry 2015 v.87 no.2 pp. 1118-1126
ISSN:
1520-6882
Subject:
detergents; dissociation; gases; ions; mass spectrometry; membrane proteins; micelles; protein structure; solubility; solubilization
Abstract:
... Noncovalent mass spectrometry (MS) is emerging as an invaluable technique to probe the structure, interactions, and dynamics of membrane proteins (MPs). However, maintaining native-like MP conformations in the gas phase using detergent solubilized proteins is often challenging and may limit structural analysis. Amphipols, such as the well characterized A8-35, are alternative reagents able to maint ...
DOI:
10.1021/ac5037022
PubMed:
25495802
PubMed Central:
PMC4636139

14. Angel’s Share Combats Wine Fraud: 14C Dating of Wine without Opening the Bottle

Author:
Fahrni Simon M.; Fuller Benjamin T.; Southon John R.
Source:
Analytical chemistry 2015 v.87 no.17 pp. 8646-8650
ISSN:
1520-6882
Subject:
chemical analysis; cork; cork stoppers; ethanol; fraud; gases; radiocarbon dating; spoilage; stable isotopes; wine industry; wines
Abstract:
... The problem of fraud continues to plague the wine industry, and detecting cases where the original bottle has been refilled with an inferior vintage is especially difficult. A novel noninvasive procedure presented here relies on radiocarbon dating the so-called angel’s share: the trace amounts of ethanol and other gases that diffuse into and through the cork as bottled wine ages and matures. These ...
DOI:
10.1021/acs.analchem.5b01998

15. CIUSuite: A Quantitative Analysis Package for Collision Induced Unfolding Measurements of Gas-Phase Protein Ions

Author:
Eschweiler Joseph D.; Rabuck-Gibbons Jessica N.; Tian Yuwei; Ruotolo Brandon T.
Source:
Analytical chemistry 2015 v.87 no.22 pp. 11516-11522
ISSN:
1520-6882
Subject:
computer software; data collection; gases; heat; instrumentation; ions; proteins; quantitative analysis; screening; spectroscopy
Abstract:
... Ion mobility-mass spectrometry (IM-MS) is a technology of growing importance for structural biology, providing complementary 3D structure information for biomolecules within samples that are difficult to analyze using conventional analytical tools through the near-simultaneous acquisition of ion collision cross sections (CCSs) and masses. Despite recent advances in IM-MS instrumentation, the resol ...
DOI:
10.1021/acs.analchem.5b03292

16. Comprehensive Size-Determination of Whole Virus Vaccine Particles Using Gas-Phase Electrophoretic Mobility Macromolecular Analyzer, Atomic Force Microscopy, and Transmission Electron Microscopy

Author:
Havlik Marlene; Marchetti-Deschmann Martina; Friedbacher Gernot; Winkler Wolfgang; Messner Paul; Perez-Burgos Laura; Tauer Christa; Allmaier Günter
Source:
Analytical chemistry 2015 v.87 no.17 pp. 8657-8664
ISSN:
1520-6882
Subject:
Western blotting; atomic force microscopy; bioactive properties; electrophoresis; fractionation; gases; gel chromatography; instrumentation; molecular weight; particle size distribution; tick-borne encephalitis; transmission electron microscopy; vaccines; virion; viruses
Abstract:
... Biophysical properties including particle size distribution, integrity, and shape of whole virus vaccine particles at different stages in tick-borne encephalitis (TBE) vaccines formulation were analyzed by a new set of methods. Size-exclusion chromatography (SEC) was used as a conservative sample preparation for vaccine particle fractionation and gas-phase electrophoretic mobility macromolecular a ...
DOI:
10.1021/acs.analchem.5b01198
PubMed:
26266988
PubMed Central:
PMC4563941

17. Decreased Gap Width in a Cylindrical High-Field Asymmetric Waveform Ion Mobility Spectrometry Device Improves Protein Discovery

Author:
Swearingen Kristian E.; Winget Jason M.; Hoopmann Michael R.; Kusebauch Ulrike; Moritz Robert L.
Source:
Analytical chemistry 2015 v.87 no.24 pp. 12230-12237
ISSN:
1520-6882
Subject:
atmospheric pressure; electric field; electrodes; fractionation; gases; ions; isoelectric focusing; liquid chromatography; peptides; proteins; proteomics; tandem mass spectrometry; yeasts
Abstract:
... High-field asymmetric waveform ion mobility spectrometry (FAIMS) is an atmospheric pressure ion mobility technique that separates gas phase ions according to their characteristic dependence of ion mobility on electric field strength. FAIMS can be implemented as a means of automated gas-phase fractionation in liquid chromatography-tandem mass spectrometry (LC-MS/MS) experiments. We modified a comme ...
DOI:
10.1021/acs.analchem.5b03199
PubMed:
26560994
PubMed Central:
PMC4777518

18. Detection, Identification, and Occurrence of Thiotetronic Acids in Drinking Water from Underground Sources by Electrospray Ionization-High Field Asymmetric Waveform Ion Mobility Spectrometry-Quadrupole Time-of-Flight-Mass Spectrometry

Author:
Lyczko Jadwiga; Beach Daniel; Gabryelski Wojciech
Source:
Analytical chemistry 2015 v.87 no.19 pp. 9884-9891
ISSN:
1520-6882
Subject:
acids; aquifers; bacterial contamination; bottled water; disinfection; dissociation; drinking water; gases; groundwater; ionization; ions; mammals; organic compounds; ozonation; pharmaceutical industry; soil bacteria; tandem mass spectrometry; toxicity; water treatment; Canada; United States
Abstract:
... This paper demonstrates that electrospray ionization (ESI) with differential ion mobility spectroscopy (FAIMS) and “soft” mass spectrometry (MS) provide unique analytical capabilities that led to the discovery of sulfur-containing polar congeners of thiotetronic acid (TA) in drinking water from underground sources in Canada and the United States. Polar TAs accumulate in underground aquifers and ap ...
DOI:
10.1021/acs.analchem.5b02372

19. Direct Analysis of Intact Biological Macromolecules by Low-Energy, Fiber-Based Femtosecond Laser Vaporization at 1042 nm Wavelength with Nanospray Postionization Mass Spectrometry

Author:
Shi Fengjian; Flanigan Paul M.; Archer Jieutonne J.; Levis Robert J.
Source:
Analytical chemistry 2015 v.87 no.6 pp. 3187-3194
ISSN:
1520-6882
Subject:
blood; desorption; energy; gases; glass; hemoglobin; ions; mass spectrometry; volatilization; wavelengths
Abstract:
... A fiber-based laser with a pulse duration of 435 fs and a wavelength of 1042 nm was used to vaporize biological macromolecules intact from the condensed phase into the gas phase for nanospray postionization and mass analysis. Laser vaporization of dried standard protein samples from a glass substrate by 10 Hz bursts of 20 pulses having 10 μs pulse separation and <50 μJ pulse energy resulted in sig ...
DOI:
10.1021/ac502563c

20. Direct Ion Imaging Approach for Investigation of Ion Dynamics in Multipole Ion Guides

Author:
Syed Sarfaraz U. A. H.; Maher Simon; Eijkel Gert B.; Ellis Shane R.; Jjunju Fred; Taylor Stephen; Heeren Ron M. A.
Source:
Analytical chemistry 2015 v.87 no.7 pp. 3714-3720
ISSN:
1520-6882
Subject:
computer software; cooling; electrodes; gases; image analysis; ionization; ions; mathematical models; radio waves; spectrometers
Abstract:
... A key requirement of electrospray ionization (ESI) and other techniques facilitating ionization at elevated pressures is the efficient transport of free gas-phase ions into the high vacuum region of the mass spectrometer. Radio frequency (RF) multipole ion guides that allow for collisional cooling are one of the most popular means of achieving this. However, their performance is highly dependent o ...
DOI:
10.1021/ac5041764

21. Direct Ionization of Solid-Phase Microextraction Fibers for Quantitative Drug Bioanalysis: From Peripheral Circulation to Mass Spectrometry Detection

Author:
Ahmad Sheelan; Tucker Michael; Spooner Neil; Murnane Darragh; Gerhard Ute
Source:
Analytical chemistry 2015 v.87 no.1 pp. 754-759
ISSN:
1520-6882
Subject:
blood sampling; cost effectiveness; drugs; food analysis; gases; ionization; ions; liquid chromatography; propranolol; solid phase microextraction; solvents; tandem mass spectrometry; washing
Abstract:
... A novel approach is described for the quantitative bioanalysis of drugs in blood samples by ionization of the analytes collected on solid-phase microextraction (SPME) fibers by mass spectrometry (MS). The technique combines the attractive features of SPME microsampling using minimal sample volumes with the speed, selectivity, and sensitivity capabilities of MS detection. The method reported in thi ...
DOI:
10.1021/ac503706n

22. Discrimination of Isomeric Carbohydrates as the Electron Transfer Products of Group II Cation Adducts by Ion Mobility Spectrometry and Tandem Mass Spectrometry

Author:
Huang Yuting; Dodds Eric D.
Source:
Analytical chemistry 2015 v.87 no.11 pp. 5664-5668
ISSN:
1520-6882
Subject:
barium; calcium; cations; dissociation; electron transfer; gases; isomers; oligosaccharides; tandem mass spectrometry
Abstract:
... The rapid and unambiguous distinction of isomeric carbohydrate structures persists as a tremendous analytical challenge. This paper reports the first exploitation of carbohydrate/metal ion interactions in concert with gas-phase ion chemistry to improve discrimination of oligosaccharide isomers by both ion mobility spectrometry and tandem mass spectrometry. This is demonstrated for two isomeric pen ...
DOI:
10.1021/acs.analchem.5b00759

23. Elucidation of Conformer Preferences for a Hydrophobic Antimicrobial Peptide by Vesicle Capture-Freeze-Drying: A Preparatory Method Coupled to Ion Mobility-Mass Spectrometry

Author:
Patrick John W.; Gamez Roberto C.; Russell David H.
Source:
Analytical chemistry 2015 v.87 no.1 pp. 578-583
ISSN:
1520-6882
Subject:
antimicrobial peptides; gases; gramicidin; hydrophobicity; ions; lipid bilayers; lipids; mass spectrometry; monitoring
Abstract:
... A novel sample preparation method to probe the solution phase structure of dimerized Gramicidin A (GA) inserted into lipid vesicle bilayers is described. This method, termed vesicle capture-freeze-drying (VCFD), when coupled with electrospray ionization-ion mobility-mass spectrometry (ESI-IM-MS), successfully demonstrates the first evidence for the preservation of membrane-bound structure in the a ...
DOI:
10.1021/ac503163g

24. Enhanced Microgas Chromatography Using Correlation Techniques for Continuous Indoor Pollutant Detection

Author:
Cesar William; Flourens Frédéric; Kaiser Claire; Sutour Christophe; Angelescu Dan E.
Source:
Analytical chemistry 2015 v.87 no.11 pp. 5620-5625
ISSN:
1520-6882
Subject:
air quality; chromatography; detection limit; gases; monitoring; pollutants; toxic substances; toxicity
Abstract:
... We present for the first time a proof-of-concept system implementing the stochastic injection techniques within a silicon-based microgas chromatograph (μGC) which differs from standard laboratory chromatographs by its small size, shorter column and corresponding elution times, and potential low cost when batch manufactured in high volumes. We demonstrate that stochastic injection techniques can en ...
DOI:
10.1021/acs.analchem.5b00687

25. Gas-Phase Chemical Separation of Phosphatidylcholine and Phosphatidylethanolamine Cations via Charge Inversion Ion/Ion Chemistry

Author:
Rojas-Betancourt Stella; Stutzman John R.; Londry Frank A.; Blanksby Stephen J.; McLuckey Scott A.
Source:
Analytical chemistry 2015 v.87 no.22 pp. 11255-11262
ISSN:
1520-6882
Subject:
anions; cations; dissociation; fatty acids; gases; ionization; phosphatidylcholines; phosphatidylethanolamines; separation
Abstract:
... The [M + H]⁺ cations formed upon electrospray ionization of the glycerophospholipids phosphatidylcholine (PC) and phosphatidylethanolamine (PE) show distinct reactivities upon gas-phase reactions with doubly deprotonated 1,4-phenylenedipropionic acid (PDPA). PC cations undergo charge inversion via adduct formation with subsequent methyl cation and proton transfer to the acid to yield [PC – CH₃]⁻ a ...
DOI:
10.1021/acs.analchem.5b02243
PubMed:
26477819
PubMed Central:
PMC5068822

26. Gas-Phase FRET Efficiency Measurements To Probe the Conformation of Mass-Selected Proteins

Author:
Czar Martin F.; Zosel Franziska; König Iwo; Nettels Daniel; Wunderlich Bengt; Schuler Benjamin; Zarrine-Afsar Arash; Jockusch Rebecca A.
Source:
Analytical chemistry 2015 v.87 no.15 pp. 7559-7565
ISSN:
1520-6882
Subject:
chemical analysis; electrospray ionization mass spectrometry; energy transfer; fluorescence; fluorescence emission spectroscopy; gases; ionization; mutants; pH; proteins; spectrometers
Abstract:
... Electrospray ionization and mass spectrometry have revolutionized the chemical analysis of biological molecules, including proteins. However, the correspondence between a protein’s native structure and its structure in the mass spectrometer (where it is gaseous) remains unclear. Here, we show that fluorescence (Förster) resonance energy transfer (FRET) measurements combined with mass spectrometry ...
DOI:
10.1021/acs.analchem.5b01591

27. Gas-Phase Rearrangement in Lysine Phosphorylated Peptides During Electron-Transfer Dissociation Tandem Mass Spectrometry

Author:
Bertran-Vicente Jordi; Schümann Michael; Hackenberger Christian P. R.; Krause Eberhard
Source:
Analytical chemistry 2015 v.87 no.14 pp. 6990-6994
ISSN:
1520-6882
Subject:
arginine; dissociation; electron transfer; gases; histidine; lysine; peptides; phosphates; phosphorylation; proteome; tandem mass spectrometry
Abstract:
... Tandem mass spectrometry (MS/MS) strategies coupled with collision-induced dissociation (CID) or radical-driven fragmentation techniques such as electron-capture dissociation (ECD) or electron-transfer dissociation (ETD) have been successfully used for comprehensive phosphoproteome analysis. However, the unambiguous characterization of the phosphorylation site remains a significant challenge due t ...
DOI:
10.1021/acs.analchem.5b01389

28. Generation of Dynamic Free-Form Temperature Gradients in a Disposable Microchip

Author:
Ha Byung Hang; Park Jinsoo; Destgeer Ghulam; Jung Jin Ho; Sung Hyung Jin
Source:
Analytical chemistry 2015 v.87 no.22 pp. 11568-11574
ISSN:
1520-6882
Subject:
DNA; absorption; gases; heat; melting; microstructure; quantitative polymerase chain reaction; single nucleotide polymorphism; sounds; temperature profiles
Abstract:
... Temperature gradients (TGs) provide an effective approach to controlling solvated molecules and creating spatiotemporally varying thermal stimuli for biochemical research. Methods developed to date for generating TGs can only create a limited set of static temperature profiles. This article describes a method for establishing dynamic free-form TGs in polydimethylsiloxane (PDMS) as well as in gases ...
DOI:
10.1021/acs.analchem.5b03457

29. High-Throughput Characterization of Small and Large Molecules Using Only a Matrix and the Vacuum of a Mass Spectrometer

Author:
Woodall Daniel W.; Wang Beixi; Inutan Ellen D.; Narayan Srinivas B.; Trimpin Sarah
Source:
Analytical chemistry 2015 v.87 no.9 pp. 4667-4674
ISSN:
1520-6882
Subject:
crystals; drugs; gases; humans; ionization; ions; metabolites; nylon; peptides; proteins; spectrometers; tandem mass spectrometry; urine
Abstract:
... Matrix assisted ionization vacuum (MAIV) rapidly generates gas-phase analyte ions from subliming solid-phase matrix:analyte crystals for analysis by mass spectrometry (MS). Ionization from the solid-phase allows the use of a variety of surfaces for introducing matrix:analyte samples to the vacuum of a mass spectrometer, including common laboratory materials, such as disposable pipet tips, filter p ...
DOI:
10.1021/ac504475x

30. Improved Data-Dependent Acquisition for Untargeted Metabolomics Using Gas-Phase Fractionation with Staggered Mass Range

Author:
Yan Zhixiang; Yan Ru
Source:
Analytical chemistry 2015 v.87 no.5 pp. 2861-2868
ISSN:
1520-6882
Subject:
fractionation; gases; humans; ions; metabolites; metabolome; metabolomics; screening; spectrometers; sulfates
Abstract:
... The inherently limited MS2 rate of the mass spectrometer is still restricting the performance of data-dependent acquisition (DDA) for untargeted metabolomics. When dealing with the complex metabolome ocean, top-n-based DDA is just scratching the surface as only a small fraction of the ions could be selected for MS2. Here, we report an improved DDA method for untargeted metabolomics using gas-phase ...
DOI:
10.1021/ac504325x

31. Ion Mobility-Derived Collision Cross Section As an Additional Measure for Lipid Fingerprinting and Identification

Author:
Paglia Giuseppe; Angel Peggi; Williams Jonathan P.; Richardson Keith; Olivos Hernando J.; Thompson J. Will; Menikarachchi Lochana; Lai Steven; Walsh Callee; Moseley Arthur; Plumb Robert S.; Grant David F.; Palsson Bernhard O.; Langridge James; Geromanos Scott; Astarita Giuseppe
Source:
Analytical chemistry 2015 v.87 no.2 pp. 1137-1144
ISSN:
1520-6882
Subject:
brain; chromatography; databases; gases; image analysis; lipids; mass spectrometry
Abstract:
... Despite recent advances in analytical and computational chemistry, lipid identification remains a significant challenge in lipidomics. Ion-mobility spectrometry provides an accurate measure of the molecules’ rotationally averaged collision cross-section (CCS) in the gas phase and is thus related to ionic shape. Here, we investigate the use of CCS as a highly specific molecular descriptor for ident ...
DOI:
10.1021/ac503715v
PubMed:
25495617
PubMed Central:
PMC4302848

32. Ion Mobility–Mass Spectrometry of Lasso Peptides: Signature of a Rotaxane Topology

Author:
Jeanne Dit Fouque Kevin; Afonso Carlos; Zirah Séverine; Hegemann Julian D.; Zimmermann Marcel; Marahiel Mohamed A.; Rebuffat Sylvie; Lavanant Hélène
Source:
Analytical chemistry 2015 v.87 no.2 pp. 1166-1172
ISSN:
1520-6882
Subject:
data collection; gases; mass spectrometry; peptides; solvents; topology
Abstract:
... Ion mobility mass spectrometry data were collected on a set of five class II lasso peptides and their branched-cyclic topoisomers prepared in denaturing solvent conditions with and without sulfolane as a supercharging agent. Sulfolane was shown not to affect ion mobility results and to allow the formation of highly charged multiply protonated molecules. Drift time values of low charged multiply pr ...
DOI:
10.1021/ac503772n

33. Liquid Extraction Surface Analysis Mass Spectrometry Coupled with Field Asymmetric Waveform Ion Mobility Spectrometry for Analysis of Intact Proteins from Biological Substrates

Author:
Sarsby Joscelyn; Griffiths Rian L.; Race Alan M.; Bunch Josephine; Randall Elizabeth C.; Creese Andrew J.; Cooper Helen J.
Source:
Analytical chemistry 2015 v.87 no.13 pp. 6794-6800
ISSN:
1520-6882
Subject:
Escherichia coli; agar; brain; gases; lipids; liver; mass spectrometry; mice; proteins
Abstract:
... Previously we have shown that liquid extraction surface analysis (LESA) mass spectrometry is suitable for the analysis of intact proteins from a range of biological substrates. Here we show that LESA mass spectrometry may be coupled with high field asymmetric waveform ion mobility spectrometry (FAIMS) for top-down protein analysis directly from thin tissue sections (mouse liver, mouse brain) and f ...
DOI:
10.1021/acs.analchem.5b01151

34. Mass Spectrometric Approach for Characterizing the Disordered Tail Regions of the Histone H2A/H2B Dimer

Author:
Saikusa Kazumi; Nagadoi Aritaka; Hara Kana; Fuchigami Sotaro; Kurumizaka Hitoshi; Nishimura Yoshifumi; Akashi Satoko
Source:
Analytical chemistry 2015 v.87 no.4 pp. 2220-2227
ISSN:
1520-6882
Subject:
acetylation; deuterium; gases; histones; mass spectrometry; mutants; nucleosomes
Abstract:
... The histone H2A/H2B dimer is a component of nucleosome core particles (NCPs). The structure of the dimer at the atomic level has not yet been revealed. A possible reason for this is that the dimer has three intrinsically disordered tail regions: the N- and C-termini of H2A and the N-terminus of H2B. To investigate the role of the tail regions of the H2A/H2B dimer structure, we characterized behavi ...
DOI:
10.1021/ac503689w

35. Mass Spectrometry Cleavable Strategy for Identification and Differentiation of Prenylated Peptides

Author:
Bhawal Ruchika P.; Sadananda Sandhya C.; Bugarin Alejandro; Laposa Brian; Chowdhury Saiful M.
Source:
Analytical chemistry 2015 v.87 no.4 pp. 2178-2186
ISSN:
1520-6882
Subject:
children; colon; epoxides; gases; genetic disorders; humans; hydrophilicity; liquid chromatography; mass spectrometry; myeloid leukemia; peptides; proteins
Abstract:
... Prenylation of protein (farnesylation and geranylgeranylation) is involved in several human cancers, such as pancreatic, colon, and acute myeloid leukemia as well as Hutchinson-Gilford progeria syndrome (HGPS), a genetic disease that is associated with premature aging for children. Current biochemical methods are not very efficient in identifying and differentiating large-scale prenylations in viv ...
DOI:
10.1021/ac503794s

36. Measurement of Gas and Aerosol Phase Absorption Spectra across the Visible and Near-IR Using Supercontinuum Photoacoustic Spectroscopy

Author:
Radney James G.; Zangmeister Christopher D.
Source:
Analytical chemistry 2015 v.87 no.14 pp. 7356-7363
ISSN:
1520-6882
Subject:
absorption; aerosols; databases; gases; photoacoustic spectroscopy; relative humidity; soot; spectrometers
Abstract:
... We demonstrate a method to measure the absorption spectra of gas and aerosol species across the visible and near-IR (500 to 840 nm) using a photoacoustic (PA) spectrometer and a pulsed supercontinuum laser source. Measurements of gas phase absorption spectra were demonstrated using H₂O₍g₎ as a function of relative humidity (RH). The measured absorption intensities and peak shapes were able to be q ...
DOI:
10.1021/acs.analchem.5b01541

37. Miniature Flow-Through Low-Temperature Plasma Ionization Source for Ambient Ionization of Gases and Aerosols

Author:
Spencer Sandra E.; Santiago Brandon G.; Glish Gary L.
Source:
Analytical chemistry 2015 v.87 no.23 pp. 11887-11892
ISSN:
1520-6882
Subject:
aerosols; caffeine; cellulose; gases; ionization; ions; pyrolysis
Abstract:
... The design and operation of an inexpensive, miniature low-temperature plasma ion source is detailed. The miniature low-temperature plasma ion source is operated in a “flow-through” configuration, wherein the gaseous or aerosolized analyte, caffeine or pyrolyzed ethyl cellulose, in a carrier gas is used as the plasma gas. In this flow-through configuration, the sensitivity for the caffeine standard ...
DOI:
10.1021/acs.analchem.5b03447

38. Molecular Structures and Ion Mobility Cross Sections: Analysis of the Effects of He and N2 Buffer Gas

Author:
Bleiholder Christian; Johnson Nicholas R.; Contreras Stephanie; Wyttenbach Thomas; Bowers Michael T.
Source:
Analytical chemistry 2015 v.87 no.14 pp. 7196-7203
ISSN:
1520-6882
Subject:
gases; Komagataella pastoris; bradykinin; humans; momentum; nitrogen; ubiquitin; acetolactate synthase; data analysis; Klebsiella pneumoniae; helium; melittin; temperature; molecular weight; alpha-amylase; chemical structure
Abstract:
... An empirically observed correlation between ion mobility cross sections in helium and nitrogen buffer gases was examined as a function of temperature, molecular size, and shape. Experimental cross sections were determined for tetraglycine, bradykinin, angiotensin 2, melittin, and ubiquitin at 300 K and in the range from 80 to 550 K on home-built instruments and calculated by the projection superpo ...
DOI:
10.1021/acs.analchem.5b01429

39. Optically Heated Ultra-Fast-Cycling Gas Chromatography Module for Separation of Direct Sampling and Online Monitoring Applications

Author:
Fischer Michael; Wohlfahrt Sebastian; Varga Janos; Matuschek Georg; Saraji-Bozorgzad Mohammad R.; Denner Thomas; Walte Andreas; Zimmermann Ralf
Source:
Analytical chemistry 2015 v.87 no.17 pp. 8634-8639
ISSN:
1520-6882
Subject:
temperature; carbon dioxide; gases; monitoring; cooling; heat; glass; quartz; air flow; thermal analysis; gas chromatography-mass spectrometry
Abstract:
... This work describes an ultrafast-cycling gas chromatography module (fast-GC module) for direct-sampling gas chromatography/mass spectrometry (GC-MS). The sample can be introduced into the fast-GC module using a common GC injector or any GC × GC modulator. The new fast-GC module offers the possibility to conduct a complete temperature cycle within 30 s. Its thermal mass is minimized by using a spec ...
DOI:
10.1021/acs.analchem.5b01879

40. Photoluminescence Spectroscopy of Mass-Selected Electrosprayed Ions Embedded in Cryogenic Rare-Gas Matrixes

Author:
Kern Bastian; Greisch Jean-François; Strelnikov Dmitry; Weis Patrick; Böttcher Artur; Ruben Mario; Schäfer Bernhard; Schooss Detlef; Kappes Manfred M.
Source:
Analytical chemistry 2015 v.87 no.23 pp. 11901-11906
ISSN:
1520-6882
Subject:
cations; dissociation; gases; ionization; neon; neutralization; photoluminescence; spectroscopy; synthesis
Abstract:
... An apparatus is presented which combines nanoelectrospray ionization for isolation of large molecular ions from solution, mass-to-charge ratio selection in gas-phase, low-energy-ion-beam deposition into a (co-condensed) inert gas matrix and UV laser-induced visible-region photoluminescence (PL) of the matrix isolated ions. Performance is tested by depositing three different types of lanthanoid dik ...
DOI:
10.1021/acs.analchem.5b03491

41. Photosynthesis of a Combinatorial Peptide Library in the Gas Phase

Author:
Lee Sunyoung; Glover Matthew S.; Reilly James P.; Clemmer David E.
Source:
Analytical chemistry 2015 v.87 no.18 pp. 9384-9388
ISSN:
1520-6882
Subject:
dissociation; gases; ionization; peptide libraries; photosynthesis; spectrometers
Abstract:
... A strategy for generating large numbers of peptides from a relatively small number of precursors based on photosynthetic combination in the gas phase is presented. In this approach, electrospray ionization is used to create a combination of proton-bound dimers from a specified set of peptides present in solution. The dimers are then accumulated and isolated in an ion trap mass spectrometer. Photoe ...
DOI:
10.1021/acs.analchem.5b02179

42. Pulse-Driven Micro Gas Sensor Fitted with Clustered Pd/SnO2 Nanoparticles

Author:
Suematsu Koichi; Shin Yuka; Ma Nan; Oyama Tokiharu; Sasaki Miyuki; Yuasa Masayoshi; Kida Tetsuya; Shimanoe Kengo
Source:
Analytical chemistry 2015 v.87 no.16 pp. 8407-8415
ISSN:
1520-6882
Subject:
electrodes; energy use and consumption; gases; monitoring; nanoparticles; risk; toluene; toxic substances; toxicity; volatile organic compounds
Abstract:
... Real-time monitoring of specific gas concentrations with a compact and portable gas sensing device is required to sense potential health risk and danger from toxic gases. For such purposes, we developed an ultrasmall gas sensor device, where a micro sensing film was deposited on a micro heater integrated with electrodes fabricated by the microelectromechanical system (MEMS) technology. The develop ...
DOI:
10.1021/acs.analchem.5b01767

43. Radial Diffusion and Penetration of Gas Molecules and Aerosol Particles through Laminar Flow Reactors, Denuders, and Sampling Tubes

Author:
Knopf Daniel A.; Pöschl Ulrich; Shiraiwa Manabu
Source:
Analytical chemistry 2015 v.87 no.7 pp. 3746-3754
ISSN:
1520-6882
Subject:
aerosols; chemical analysis; engineering; equations; gases; laminar flow; ozone; physical chemistry; prediction; reaction kinetics
Abstract:
... Flow reactors, denuders, and sampling tubes are essential tools for many applications in analytical and physical chemistry and engineering. We derive a new method for determining radial diffusion effects and the penetration or transmission of gas molecules and aerosol particles through cylindrical tubes under laminar flow conditions using explicit analytical equations. In contrast to the tradition ...
DOI:
10.1021/ac5042395

44. Rapid Quantification of Digitoxin and Its Metabolites Using Differential Ion Mobility Spectrometry-Tandem Mass Spectrometry

Author:
Bylda Caroline; Thiele Roland; Kobold Uwe; Bujotzek Alexander; Volmer Dietrich A.
Source:
Analytical chemistry 2015 v.87 no.4 pp. 2121-2128
ISSN:
1520-6882
Subject:
blood serum; cesium; chromatography; digitoxigenin; digitoxin; drugs; gases; humans; mass spectrometry; metabolites; metal ions; molecular weight; quantitative analysis; volatile compounds
Abstract:
... This study focuses on the quantitative analysis of the cardiac glycoside drug digitoxin and its three main metabolites digitoxigenin-bisdigitoxose, digitoxigenin-monodigitoxose, and digitoxigenin using electrospray ionization-differential ion mobility spectrometry-tandem mass spectrometry (ESI-DMS-MS/MS). Despite large molecular weight differences, gas-phase separation of the four compounds in the ...
DOI:
10.1021/ac503187z

45. Rectangular Ion Funnel: A New Ion Funnel Interface for Structures for Lossless Ion Manipulations

Author:
Chen Tsung-Chi; Webb Ian K.; Prost Spencer A.; Harrer Marques B.; Norheim Randolph V.; Tang Keqi; Ibrahim Yehia M.; Smith Richard D.
Source:
Analytical chemistry 2015 v.87 no.1 pp. 716-722
ISSN:
1520-6882
Subject:
electric field; electrodes; gases; optics; trapping
Abstract:
... Structures for lossless ion manipulations (SLIM) have recently demonstrated the ability for near lossless ion focusing, transfer, and trapping in subatmospheric pressure regions. While lossless ion manipulations are advantageously applied to the applications of ion mobility separations and gas phase reactions, ion introduction through ring electrode ion funnels or more conventional ion optics to S ...
DOI:
10.1021/ac503564c
PubMed:
25409343
PubMed Central:
PMC4287841

46. Sample Preparation: A Crucial Factor for the Analytical Performance of Rationally Designed MALDI Matrices

Author:
Wiangnon Kanjana; Cramer Rainer
Source:
Analytical chemistry 2015 v.87 no.3 pp. 1485-1488
ISSN:
1520-6882
Subject:
crystallization; employment; gases; physicochemical properties; topology
Abstract:
... Evidence is presented that the performance of the rationally designed MALDI matrix 4-chloro-α-cyanocinnamic acid (ClCCA) in comparison to its well-established predecessor α-cyano-4-hydroxycinnamic acid (CHCA) is significantly dependent on the sample preparation, such as the choice of the target plate. In this context, it becomes clear that any rational designs of MALDI matrices and their successfu ...
DOI:
10.1021/ac504412p

47. Selectivity of Terahertz Gas-Phase Spectroscopy

Author:
Smith Ryan M.; Arnold Mark A.
Source:
Analytical chemistry 2015 v.87 no.21 pp. 10679-10683
ISSN:
1520-6882
Subject:
acetaldehyde; acetonitrile; ammonia; ethanol; gases; methanol; spectroscopy
Abstract:
... Analytical potential of terahertz (THz) spectroscopy is assessed by comparing selectivity for a set of eight environmentally important gases over THz and infrared (IR) optical frequencies. Selectivity coefficients are determined over selected spectral regions for acetaldehyde, acetonitrile, ethanol, water, methanol, ammonia, propionaldehyde, and propionitrile. These selectivity coefficients quanti ...
DOI:
10.1021/acs.analchem.5b03028

48. Sensing Signatures Mediated by Chemical Structure of Molecular Solids in Laser-Induced Plasmas

Author:
Serrano Jorge; Moros Javier; Laserna J. Javier
Source:
Analytical chemistry 2015 v.87 no.5 pp. 2794-2801
ISSN:
1520-6882
Subject:
atomization; chemical structure; diagnostic techniques; emissions; energy; fluorescence; free radicals; gases; ions; irradiation; mass spectrometry; monitoring; organic compounds; wavelengths
Abstract:
... Laser ablation of organic compounds has been investigated for almost 30 years now, either in the framework of pulse laser deposition for the assembling of new materials or in the context of chemical sensing. Various monitoring techniques such as atomic and molecular fluorescence, time-of-flight mass spectrometry, and optical emission spectroscopy have been used for plasma diagnostics in an attempt ...
DOI:
10.1021/acs.analchem.5b00212

49. Structural Characterization of Methylenedianiline Regioisomers by Ion Mobility-Mass Spectrometry, Tandem Mass Spectrometry, and Computational Strategies. 2. Electrospray Spectra of 3-Ring and 4-Ring Isomers

Author:
Stow SarahM.; Onifer Tiffany M.; Forsythe Jay G.; Nefzger Hartmut; Kwiecien Nicholas W.; May Jody C.; McLean John A.; Hercules David M.
Source:
Analytical chemistry 2015 v.87 no.12 pp. 6288-6296
ISSN:
1520-6882
Subject:
biphenyl; gases; isomers; polyurethanes; tandem mass spectrometry
Abstract:
... Building on results from our previous study of 2-ring methylenedianiline (MDA), a combined mass spectrometry approach utilizing ion mobility-mass spectrometry (IM-MS) and tandem mass spectrometry (MS/MS) coupled with computational methods enables the structural characterization of purified 3-ring and 4-ring MDA regioisomers in this current study. The preferred site of protonation for the 3-ring an ...
DOI:
10.1021/acs.analchem.5b01084
PubMed:
25971782
PubMed Central:
PMC5642105

50. Structure and Dynamics of a Protein–Surfactant Assembly Studied by Ion-Mobility Mass Spectrometry and Molecular Dynamics Simulations

Author:
Borysik Antoni J.
Source:
Analytical chemistry 2015 v.87 no.17 pp. 8970-8976
ISSN:
1520-6882
Subject:
gases; mass spectrometry; membrane proteins; molecular dynamics; protein structure; solvents; surfactants; Polar Regions
Abstract:
... The structure and dynamics of a protein–surfactant assembly studied by ion-mobility mass spectrometry (IMS) and vacuum molecular dynamics (MD) simulations is reported. Direct evidence is provided for the ability of the surfactant dodecyl-β-D-maltoside (DDM) to prevent charge-induced unfolding of the membrane protein (PagP) in the gas-phase. Restraints obtained by IMS are used to map the surfactant ...
DOI:
10.1021/acs.analchem.5b02172

51. Surface-Induced Dissociation Mass Spectra as a Tool for Distinguishing Different Structural Forms of Gas-Phase Multimeric Protein Complexes

Author:
Quintyn Royston S.; Zhou Mowei; Yan Jing; Wysocki Vicki H.
Source:
Analytical chemistry 2015 v.87 no.23 pp. 11879-11886
ISSN:
1520-6882
Subject:
C-reactive protein; concanavalin A; dissociation; energy; gases; mass spectrometry; molecular models; prealbumin; protein unfolding; topology; uncertainty
Abstract:
... One attractive feature of ion mobility mass spectrometry (IM-MS) lies in its ability to provide experimental collision cross section (CCS) measurements, which can be used to distinguish different conformations that a protein complex may adopt during its gas-phase unfolding. However, CCS values alone give no detailed information on subunit structure within the complex. Consequently, structural char ...
DOI:
10.1021/acs.analchem.5b03441

52. Ultratrace Measurement of Acetone from Skin Using Zeolite: Toward Development of a Wearable Monitor of Fat Metabolism

Author:
Yamada Yuki; Hiyama Satoshi; Toyooka Tsuguyoshi; Takeuchi Shoji; Itabashi Keiji; Okubo Tatsuya; Tabata Hitoshi
Source:
Analytical chemistry 2015 v.87 no.15 pp. 7588-7594
ISSN:
1520-6882
Subject:
acetone; adsorption; desorption; diet; exercise; gases; humans; hydrophobicity; lipid metabolism; zeolites
Abstract:
... Analysis of gases emitted from human skin and contained in human breath has received increasing attention in recent years for noninvasive clinical diagnoses and health checkups. Acetone emitted from human skin (skin acetone) should be a good indicator of fat metabolism, which is associated with diet and exercise. However, skin acetone is an analytically challenging target because it is emitted in ...
DOI:
10.1021/acs.analchem.5b00296

53. Unified pH Values of Liquid Chromatography Mobile Phases

Author:
Suu Agnes; Jalukse Lauri; Liigand Jaanus; Kruve Anneli; Himmel Daniel; Krossing Ingo; Rosés Martí; Leito Ivo
Source:
Analytical chemistry 2015 v.87 no.5 pp. 2623-2630
ISSN:
1520-6882
Subject:
acidity; acids; additives; aqueous solutions; gases; ionization; liquid chromatography; mass spectrometry; pH; solvents
Abstract:
... This work introduces a conceptually new approach of measuring pH of mixed-solvent liquid chromatography (LC) mobile phases. Mobile phase pH is very important in LC, but its correct measurement is not straightforward, and all commonly used approaches have deficiencies. The new approach is based on the recently introduced unified pH (pHₐbₛ) scale, which enables direct comparison of acidities of solu ...
DOI:
10.1021/ac504692m