Analytical Chemistry

Headspace Gas Monitoring of Gut Microbiota Using Targeted and Globally Optimized Targeted Secondary Electrospray Ionization Mass Spectrometry

Haorong Li, Mengyang Xu, and Jiangjiang Zhu

This study aimed to sensitively detect volatile metabolites from the headspace of in vitro gut microbial culture in a human colonic model (HCM). Two SESI-tandem mass spectrometry panels with a comparable number of targeted metabolites/features were established

Differentiating Antibiotic-Resistant Staphylococcus aureus Using Secondary Electrospray Ionization Tandem Mass Spectrometry

Haorong Li and Jiangjiang Zhu

SESIMS/MS was applied to examine the VOC metabolome of a pair of isogenic methicillin-susceptible and resistant Staphylococcus aureus (MSSA and MRSA) strains. Our results indicated that MSSA and MRSA strains can be clearly differentiated Furthermore, we studied the stress response of MSSA and MRSA to antibiotics treatment

Mass-spectrometric detection of omega-oxidation products of aliphatic fatty acids in exhaled breath

Mass-spectrometric detection of omega-oxidation products of aliphatic fatty acids in exhaled breath

M. T. Gaugg, T. Bruderer, N. Nowak, L. Eiffert, P. M-L Sinues, M. Kohler, R. Zenobi

Omega-oxidation is a fatty acid degradation pathway that can occur alternatively to the dominant b-oxidation. The dysregulation of fatty acid oxidation has been related with a variety of diseases, termed fatty acid oxidation disorders. This work shows evidence for real-time detection in exhaled breath of the complete series of saturated linear w-hydroxyalkanoic acids, w-oxoalkanoic acids and alkanedioic acids with carbon chain lengths of 5-15.

Use of Mass Spectrometric Vapor Analysis To Improve Canine Explosive Detection Efficiency

Use of Mass Spectrometric Vapor Analysis To Improve Canine Explosive Detection Efficiency

Ta-Hsuan Ong*, Ted Mendum, Geoff Geurtsen, Jude Kelley, Alla Ostrinskaya, Roderick Kunz

Canines remain the gold standard for explosives detection in many situations, and there is an ongoing desire for them to perform at the highest level. This goal requires canine training to be approached similarly to scientific sensor design. A sensitive, real-time (∼1 s) vapor analysis mass spectrometer was developed to provide tools, techniques, and knowledge to better understand, train, and utilize canines.

Capturing in Vivo Plant Metabolism by Real-Time Analysis of Low to High Molecular Weight Volatiles

Capturing in Vivo Plant Metabolism by Real-Time Analysis of Low to High Molecular Weight Volatiles

C. Barrios-Collado, D. Garcia-Gomez, R. Zenobi, G. Vidal-de-MiguelAlfredo J. Ibanez, and P. M-L Sinues

The authors document how hundreds of species can be tracked with an unparalleled time resolution of 2 min during day−night cycles. To further illustrate the capabilities of SESI-MS for volatile organic compounds (VOCs) analysis, they subjected the plant to mechanical damage and monitored its response.

Real-Time High-Resolution Tandem Mass Spectrometry Identifies Furan Derivatives in Exhaled Breath

Real-Time High-Resolution Tandem Mass Spectrometry Identifies Furan Derivatives in Exhaled Breath

D. García-Gómez, L. Bregy, C. Barrios-Collado, G. Vidal-de-Miguel and R. Zenobi

The identification of chemical compounds in exhaled human breath is promising in the search for new biomakers of diseases. However, the analytical techniques used nowadays are not capable of achieving a robust identification, especially in real-time analysis.

Identification of 2‑Alkenals, 4‑Hydroxy-2-alkenals, and 4‑Hydroxy-2,6-alkadienals in Exhaled Breath Condensate by UHPLC-HRMS and in Breath by Real-Time HRMS

Identification of 2‑Alkenals, 4‑Hydroxy-2-alkenals, and 4‑Hydroxy-2,6-alkadienals in Exhaled Breath Condensate by UHPLC-HRMS and in Breath by Real-Time HRMS

D. García-Gómez, P. M.-L. Sinues, C. Barrios-Collado, G. Vidal-de Miguel, M. Gaugg, and R. Zenobi

In recent years, breath analysis in real time has become a noninvasive alternative for the diagnosis of diseases and for molecular fingerprinting of exhaled breath. However, the techniques used lack the capabilities for proper identification of the compounds found in the exhalome.

Direct quantification of chemical warfare agents and related compounds at low ppt levels: comparing active capillary DBDI and SESI mass spectrometry

Direct quantification of chemical warfare agents and related compounds at low ppt levels: comparing active capillary DBDI and SESI mass spectrometry

J-C Wolf, M. Schaer, P. Siegenthaler, R. Zenobi

A novel active capillary dielectric barrier discharge plasma ionization (DBDI) technique for mass spectrometry is applied to the direct detection of thirteen chemical warfare related compounds, including sarin, and compared to secondary electrospray ionization (SESI) in terms of selectivity and sensitivity.

Monitoring Diurnal Changes in Exhaled Human Breath

Monitoring Diurnal Changes in Exhaled Human Breath

P. M-L Sinues, M. Kohler and R. Zenobi

The development of noninvasive analytical techniques is of interest to the field of chronobiology, in order to reveal the human metabolome that seems to show temporal patterns and to predict internal body time. We report on the real-time mass spectrometric analysis of human breath as a potential method to be used in this field.

Low-Sample Flow Secondary Electrospray Ionization: Improving Vapor Ionization Efficiency

Low-Sample Flow Secondary Electrospray Ionization: Improving Vapor Ionization Efficiency

G. Vidal-de-Miguel, M. Macía, P. Pinacho, and J. Blanco

In secondary electrospray ionization (SESI) systems, gaseous analytes exposed to an elecrospray plume become ionized after charge is transferred from the charging electrosprayed particles to the sample species. Current SESI systems have shown a certain potential. However, their ionization efficiency is limited by …

Direct Analysis of Fatty Acid Vapors in Breath by Electrospray Ionization and Atmospheric Pressure Ionization-Mass Spectrometry

Direct Analysis of Fatty Acid Vapors in Breath by Electrospray Ionization and Atmospheric Pressure Ionization-Mass Spectrometry

P. M-L Sinues, J. F. de la Mora

Real time analysis of human breath is achieved in an atmospheric pressure ionization mass spectrometer (API-MS) by negatively charging exhaled vapors via contact with an electrospray cloud. The spectrum observed is dominated by a wide range of deprotonated fatty acids, including saturated chains up to C14. Above C14, the background from cutaneous sources becomes dominant.

Differentiation of Maturity and Quality of Fruit Using Noninvasive Extractive Electrospray Ionization Quadrupole Time-of-Flight Mass Spectrometry

Differentiation of Maturity and Quality of Fruit Using Noninvasive Extractive Electrospray Ionization Quadrupole Time-of-Flight Mass Spectrometry

H. Chen, Y. Sun, A. Wortmann, H. Gu, R. Zenobi

Maturity is an essential factor that determines storage life and final quality of most fruits and vegetables. Maturity monitoring is thus of paramount importance for postharvest handling and fruit quality regulation. Ideal analytical procedures for maturity investigation require high sensitivity, specificity, and high throughput and should be noninvasive.

Secondary Electrospray Ionization-Ion Mobility Spectrometry for Explosive Vapor Detection

Secondary Electrospray Ionization-Ion Mobility Spectrometry for Explosive Vapor Detection

M. Tam and H. H. Hill, Jr.

The unique capability of secondary electrospray ionization (SESI) as a nonradioactive ionization source to detect analytes in both liquid and gaseous samples was evaluated using aqueous solutions of three common military explosives: cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX), nitroglycerin (NG) and pentaerythritol tetranitrate (PETN).

Secondary Ionization of Chemical Warfare Agent Simulants: Atmospheric Pressure Ion Mobility Time-of-Flight Mass Spectrometry

Secondary Ionization of Chemical Warfare Agent Simulants: Atmospheric Pressure Ion Mobility Time-of-Flight Mass Spectrometry

W. E. Steiner, B. H. Clowers, P. E. Haigh, and H. H. Hill

For the first time, the use of a traditional ionization source for ion mobility spectrometry (radioactive nickel (63Ni) beta emission ionization) and three alternative ionization sources (electrospray ionization (ESI), secondary electrospray ionization (SESI), and electrical discharge (corona) ionization (CI)) were employed with …

Secondary Electrospray Ionization Ion Mobility Spectrometry/Mass Spectrometry of Illicit Drugs

Secondary Electrospray Ionization Ion Mobility Spectrometry/Mass Spectrometry of Illicit Drugs

C. Wu, W. F. Siems, and H. H. Hill, Jr.

A secondary electrospray ionization (SESI) method was developed as a nonradioactive ionization source for ion mobility spectrometry (IMS). This SESI method relied on the gas-phase interaction between charged particles created by electrospray ionization (ESI) and neutral gaseous sample molecules. Mass spectrometry (MS) was used as …