Utilization of a Soft Ionization Mass Spectrometer for Ultra High Sensitivity and Fast Response Emission Measurements

1998 ◽  
Author(s):  
Kotaro Akashi ◽  
Kaori Inoue ◽  
Masayuki Adachi ◽  
Kozo Ishida ◽  
Johannes Villinger ◽  
...  
Keyword(s):  
Mass Spectrometer ◽  
High Sensitivity ◽  
Fast Response ◽  
Ionization Mass ◽  
Soft Ionization

Isobutane Chemical Ionization Mass Spectrographic Examination of Explosives

1975 ◽  
Vol 58 (4) ◽  
pp. 734-742 ◽  
Author(s):  
Richard Saferstein ◽  
Jew-Ming Chao ◽  
John J Manura
Keyword(s):  
Mass Spectrometer ◽  
Mass Spectra ◽  
Thermal Instability ◽  
Chemical Ionization ◽  
High Sensitivity ◽  
Gas Pressure ◽  
Ionization Mass ◽  
Pentaerythritol Tetranitrate ◽  
Residue Detection ◽  
Acetone Extracts

Abstract The detection of explosive residues in debris is difficult because of the thermal instability of many explosives along with the high sensitivity requirements of the analyses. The isobutane chemical ionization (CI) mass spectra of common civilian and military explosives were obtained under different instrumental parameters. The intent of the study was to determine the feasibility of applying CI to residue detection. The CI spectra of the explosives 1,3,5-trinitro-1,3,5-triazocydohexane, 1,3,5,7-tetraazocyclooctane, and pentaerythritol tetranitrate were shown to be particularly sensitive to the conditions of source temperature and reagent gas pressure. These parameters were adjusted to yield the least complex CI spectra for the explosives studied. The simplicity of the CI spectra obtained makes it a feasible technique for detecting explosive residues in the presence of extraneous materials found in the acetone extracts of debris material. Placement of the extract into the direct probe of the CI mass spectrometer eliminates the need for prior chromatographic treatment of the extract and would optimize the high sensitivity of the CI technique.

scholarly journals Chemical ionization mass spectrometer (CIMS) for ambient measurements of ammonia

2010 ◽  
Vol 3 (2) ◽  
pp. 1133-1162 ◽  
Author(s):  
D. R. Benson ◽  
M. Al-Refai ◽  
S.-H. Lee
Keyword(s):  
Mass Spectrometer ◽  
Chemical Ionization ◽  
Fast Response ◽  
Ionization Mass ◽  
Experimental Conditions ◽  
Molecule Reaction ◽  
Mixing Ratios ◽  
Ambient Nh3 ◽  
Ambient Measurements

Abstract. This study describes a chemical ionization mass spectrometer (CIMS) for fast response, in-situ measurements for gas phase ammonia. Protonated ethanol ions were used as the ion-molecule reaction reagent. The CIMS sensitivity was estimated to be between 4–25 Hz/pptv with 30% uncertainty. The instrument background was below 1 ppbv and at lowest was 300 pptv. The uncertainty associated with the instrumental background was less than 30 pptv under the optimized experimental conditions. The time response was less than 30 s, and the detection limit was approximately 60 pptv. This CIMS was used to measure the ambient NH3 in Kent, Ohio, for several weeks throughout three seasons. The measured ammonia mixing ratios were usually at the sub-ppbv level, and higher during the spring (200±120 pptv) than in the winter (60±75 pptv) and fall (150±80 pptv).

scholarly journals A Chemical Ionization Mass Spectrometer for ambient measurements of Ammonia

2010 ◽  
Vol 3 (4) ◽  
pp. 1075-1087 ◽  
Author(s):  
D. R. Benson ◽  
A. Markovich ◽  
M. Al-Refai ◽  
S.-H. Lee
Keyword(s):  
Mass Spectrometer ◽  
Power Plants ◽  
Chemical Ionization ◽  
Background Level ◽  
Fast Response ◽  
Integration Time ◽  
Ionization Mass ◽  
Mixing Ratios ◽  
Optimized Conditions ◽  
Ambient Measurements

Abstract. This study presents a chemical ionization mass spectrometer (CIMS) for fast response, in-situ measurements of gas phase ammonia (NH3). The NH3 background level detected with the CIMS ranged between 0.3–1 ppbv, with an uncertainty of 30 pptv under optimized conditions. The instrument sensitivity varied from 4–25 Hz/pptv for >1 MHz of reagent ion signals (protonated ethanol ions), with a 30% uncertainty estimated based on variability in calibration signals. The CIMS detection limit for NH3 was ~60 pptv at a 1 min integration time (3 sigma). The CIMS time response was <30 s. This new NH3-CIMS has been used for ambient measurements in Kent, Ohio, for several weeks throughout three seasons. The measured NH3 mixing ratios were usually at the sub-ppbv level and higher in spring (200 ± 120 pptv) than in winter (60 ± 75 pptv) and fall (150 ± 80 pptv). High emissions of SO2 from power plants in this region, and thus possible high acidity of aerosol particles, may explain these low NH3 mixing ratios in general.

scholarly journals Elucidation of the Mechanism of Action for Metal Based Anticancer Drugs by Mass Spectrometry-Based Quantitative Proteomics

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 581 ◽  
Author(s):  
Shuailong Jia ◽  
Runjing Wang ◽  
Kui Wu ◽  
Hongliang Jiang ◽  
Zhifeng Du
Keyword(s):  
Mass Spectrometry ◽  
Anticancer Drugs ◽  
Mechanism Of Action ◽  
Quantitative Proteomics ◽  
High Sensitivity ◽  
Mass Spectrometric ◽  
Protein Adducts ◽  
Ionization Mass ◽  
Soft Ionization ◽  
Binding Partners

The discovery of the anticancer activity of cisplatin and its clinical application has opened a new field for studying metal-coordinated anticancer drugs. Metal-based anticancer drugs, such as cisplatin, can be transported to cells after entering into the human body and form metal–DNA or metal–protein adducts. Then, responding proteins will recognize adducts and form stable complexes. The proteins that were binding with metal-based anticancer drugs were relevant to their mechanism of action. Herein, investigation of the recognition between metal-based anticancer drugs and its binding partners will further our understanding about the pharmacology of cytotoxic anticancer drugs and help optimize the structure of anticancer drugs. The “soft” ionization mass spectrometric methods have many advantages such as high sensitivity and low sample consumption, which are suitable for the analyses of complex biological samples. Thus, MS has become a powerful tool for the identification of proteins binding or responding to metal-based anticancer drugs. In this review, we focused on the mass spectrometry-based quantitative strategy for the identification of proteins specifically responding or binding to metal-based anticancer drugs, ultimately elucidating their mechanism of action.

scholarly journals Atmospheric amines and ammonia measured with a Chemical Ionization Mass Spectrometer (CIMS)

2014 ◽  
Vol 14 (11) ◽  
pp. 16411-16450 ◽  
Author(s):  
Y. You ◽  
V. P. Kanawade ◽  
J. A. de Gouw ◽  
A. B. Guenther ◽  
S. Madronich ◽  
...  
Keyword(s):  
Mass Spectrometer ◽  
Biomass Burning ◽  
Chemical Ionization ◽  
Fast Response ◽  
Daily Basis ◽  
Anthropogenic Sources ◽  
Ionization Mass ◽  
Southeastern Us ◽  
Temperature Dependences ◽  
Southeast Us

Abstract. We report ambient measurements of amines and ammonia with a~fast response chemical ionization mass spectrometer (CIMS) in a southeastern US forest in Alabama and a~moderately polluted Midwestern site during the summer. In the Alabama forest, mostly C3-amines (from pptv to tens of pptv) and ammonia (up to 2 ppbv) were detected on a daily basis. C3-amines and ammonia showed similar diurnal trends and temperature and wind direction dependences, and were not associated with transported CO and SO2 plumes. Consistent with temperature dependences, amine and ammonia in the gas and aerosol phases showed opposite diurnal trends, indicating gas-to-particle partitioning of amines and ammonia. Temperature dependences also imply reversible processes of amines and ammonia evaporation from soil surfaces in daytime and deposition of amines and ammonia to soil surfaces at nighttime. Various amines (C1–C6) at the pptv level were observed in the transported biomass burning plumes, showing that biomass burning can be a substantial source of amines in the Southeast US. At the moderately polluted Kent site, higher concentrations of amines (C1–C6, from pptv to tens of pptv) and ammonia (up to 6 ppbv) were detected. Diurnal variations of C1- to C3-amines and ammonia were correlated with the ambient temperature. C4- to C6-amines showed abrupt increases during the nighttime, suggesting that they were emitted from local sources. These abundant amines and ammonia may in part explain the frequent new particle formation events reported from Kent. Lower amine concentrations at the rural forested site highlight the importance of constraining anthropogenic sources of amines.

scholarly journals Atmospheric amines and ammonia measured with a chemical ionization mass spectrometer (CIMS)

2014 ◽  
Vol 14 (22) ◽  
pp. 12181-12194 ◽  
Author(s):  
Y. You ◽  
V. P. Kanawade ◽  
J. A. de Gouw ◽  
A. B. Guenther ◽  
S. Madronich ◽  
...  
Keyword(s):  
Gas Phase ◽  
Mass Spectrometer ◽  
Biomass Burning ◽  
Chemical Ionization ◽  
Fast Response ◽  
Submicron Particles ◽  
Primary Amines ◽  
Ionization Mass ◽  
Forest Site ◽  
Southeastern Us

Abstract. We report measurements of ambient amines and ammonia with a fast response chemical ionization mass spectrometer (CIMS) in a southeastern US forest and a moderately polluted midwestern site during the summer. At the forest site, mostly C3-amines (from pptv to tens of pptv) and ammonia (up to 2 ppbv) were detected, and they both showed temperature dependencies. Aerosol-phase amines measured thermal-desorption chemical ionization mass spectrometer (TDCIMS) showed a higher mass fraction in the evening with cooler temperatures and lower in the afternoon with warmer temperatures, a trend opposite to the gas-phase amines. Concentrations of aerosol-phase primary amines measured with Fourier transform infrared spectroscopy (FTIR) from micron and submicron particles were 2 orders of magnitude higher than the gas-phase amines. These results indicate that gas to particle conversion is one of the major processes that control the ambient amine concentrations at this forest site. Temperature dependencies of C3-amines and ammonia also imply reversible processes of evaporation of these nitrogen-containing compounds from soil surfaces in daytime and deposition to soil surfaces at nighttime. During the transported biomass burning plume events, various amines (C1–C6) appeared at the pptv level, indicating that biomass burning is a substantial source of amines in the southeastern US. At the moderately polluted Kent site, there were higher concentrations of C1- to C6-amines (pptv to tens of pptv) and ammonia (up to 6 ppbv). C1- to C3-amines and ammonia were well correlated with the ambient temperature. C4- to C6-amines showed frequent spikes during the nighttime, suggesting that they were emitted from local sources. These abundant amines and ammonia may in part explain the frequent new particle formation events reported from Kent. Higher amine concentrations measured at the polluted site than at the rural forested site highlight the importance of constraining anthropogenic emission sources of amines.

scholarly journals Tin Disulfide-Coated Microfiber for Humidity Sensing with Fast Response and High Sensitivity

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 648
Author(s):  
Aijie Liang ◽  
Jingyuan Ming ◽  
Wenguo Zhu ◽  
Heyuan Guan ◽  
Xinyang Han ◽  
...  
Keyword(s):  
Humidity Sensor ◽  
Small Diameter ◽  
High Sensitivity ◽  
Large Change ◽  
Small Variation ◽  
Response Speed ◽  
Fast Response ◽  
Tin Disulfide ◽  
Recovery Times ◽  
Response And Recovery

Breath monitoring is significant in assessing human body conditions, such as cardiac and pulmonary symptoms. Optical fiber-based sensors have attracted much attention since they are immune to electromagnetic radiation, thus are safe for patients. Here, a microfiber (MF) humidity sensor is fabricated by coating tin disulfide (SnS2) nanosheets onto the surface of MF. The small diameter (~8 μm) and the long length (~5 mm) of the MF promise strong interaction between guiding light and SnS2. Thus, a small variation in the relative humidity (RH) will lead to a large change in optical transmitted power. A high RH sensitivity of 0.57 dB/%RH is therefore achieved. The response and recovery times are estimated to be 0.08 and 0.28 s, respectively. The high sensitivity and fast response speed enable our SnS2-MF sensor to monitor human breath in real time.

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