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Logo: GEM/Leibniz Universität Hannover
Logo Leibniz Universität Hannover
Logo: GEM/Leibniz Universität Hannover
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Electron capture detector with non-radioactive electron source

Bild zum Projekt Electron capture detector with non-radioactive electron source

Kurzbeschreibung:

Gas chromatographs equipped with electron capture detectors (ECD) are widely used for the analysis of electron affine substances such as pesticides, herbicides or chlorofluorocarbons. Achieving limits of detection in the low pptv-range, electron capture detectors are the most sensitive detectors available for such compounds. Based on their operating principle, they require free electrons at atmospheric pressure, which are usually generated by using a β--decay. However, the use of radioactive materials leads to regulatory restrictions regarding purchase, operation and disposal. Therefore, we developed a new electron capture detector using our non-radioactive electron source, which is not subject to these limitations and offers further advantages such as adjustable and higher electron densities and energies.

 

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Non-radioactive electron sources for fast high sensitive sensor systems

Bild zum Projekt Non-radioactive electron sources for fast high sensitive sensor systems

Förderung durch:

This work is supported by the German Federal Ministry of Education and Research (BMBF) under the grant 13N12820.

Kurzbeschreibung:

Most ion mobility spectrometers (IMS) employ a radioactive β-source to ionize the target analytes. However, because of the potential hazards and the associated handling restrictions regarding radioactive materials non-radioactive ionization sources are of increasing importance. The aim of this research project is the development of non-radioactive electron sources, which are used both in ion mobility spectrometry for ionization as well as in other sensor systems. Here, one advantage is that non-radioactive electron sources generate identical ion species as radioactive electron sources. A further advantage of non-radioactive electron sources is the controllability of the electron emission and hence the ionization process and the consequent opportunity to develop completely new sensor principles.

 

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FEM simulation of ion trajectories within ion mobility spectrometer or mass spectrometer

Bild zum Projekt FEM simulation of ion trajectories within ion mobility spectrometer or mass spectrometer

Kurzbeschreibung:

Using FEM Software (Comsol Multiphysics), ion trajectories within ion mobility spectrometers (IMS) at atmospheric pressure or within mass spectrometers (MS) at vacuum conditions are simulated. Depending on the application, the influence of diffusion, migration, charge repulsion, ion generation and the transient electric field are considered. The simulation results are used to optimize IMS or MS operating parameters and geometry.

 

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Closed gas loop, high-resolution IMS with gas chromatographic pre-separation for breath gas analysis

Bild zum Projekt Closed gas loop, high-resolution IMS with gas chromatographic pre-separation for breath gas analysis

Kurzbeschreibung:

In many breath gas analysis applications, real-time and bed-site analysis is required to achieve true applicability for clinical diagnosis. Thus, we built a compact, closed gas loop, high-resolution GC-IMS. The ion mobility spectrometer achieves a mobility resolution of R=90. The GC-IMS is equipped with a filter re-circulation system providing a continuous supply of dry and clean drift gas, so that no external supply is needed. Hence, the entire system fits in a 19″ housing (6 RU height).

 

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Mercury vapor sensor

Bild zum Projekt Mercury vapor sensor

Kurzbeschreibung:

The aim of this project is to develop a miniaturized mercury sensor to monitor the mercury concentration in air. Mercury forms amalgam in connection with gold. This effect can be used to determine the presence and concentration of mercury, since the formation of amalgam influences various physical parameters.

 

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High kinetic energy ion mobility spectrometry (HiKE-IMS)

Bild zum Projekt High kinetic energy ion mobility spectrometry (HiKE-IMS)

Förderung durch:

This research is founded by the German Research Foundation (DFG)

Kurzbeschreibung:

The crucial problem in most real-life applications of ion mobility spectrometers is the sample ionization, as it limits the detectability of many substances and is the primary source of matrix effects. In this project, a novel approach using reactant ions with high kinetic energy at reduced pressure is employed in order to minimize these problems and even allow quantitative measurements using ion mobility spectrometers. For example, it is possible to detect ppbv-concentrations of benzene in the presence of toluene and xylene in ppmv-concentrations

 

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Chemical ionization detector for gas chromatography

Bild zum Projekt Chemical ionization detector for gas chromatography

Kurzbeschreibung:

Ion mobility spectrometers deliver limits of detection in the low pptv-range within a measuring time of less than a second. The goal of this project is to transfer this sensitivity to a simple low-cost detector for gas chromatography.

 

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Measurement electronics

Bild zum Projekt Measurement electronics

Kurzbeschreibung:

Virtually every measurement setup requires various control signals and a data acquisition system in order to function. The performance of these devices has a significant impact on the overall performance of the entire measurement setup. Thus, crucial components such as fast high voltage switches or picoampere amplifiers as well as a modular bus system were developed and manufactured in-house.

 

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Data acquisition software for ion mobility spectrometers

Bild zum Projekt Data acquisition software for ion mobility spectrometers

Kurzbeschreibung:

In order to control all parameters of a measurement setup, carry out automated measurements and analyze the generated data, a custom software suite has been developed using LabVIEW. It allows direct control of both our custom-built bus system as well as external devices, acquires and stores ion mobility spectra together with all relevant measurement parameters and allows the user to implement additional custom functions through a special scripting language.

 

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Field asymmetric time of flight ion mobility spectrometry

Bild zum Projekt Field asymmetric time of flight ion mobility spectrometry

Förderung durch:

This work has been supported by the German Federal Ministry of Economics and Technology (BMWi), under the Grant KF3238301NT3 upon decision of the German Bundestag

Kurzbeschreibung:

In this work, we are developing a new concept for miniaturized and low cost ion mobility spectrometers (IMS) manufactured from printed circuit boards (PCB). The goal is a system which is small and cheap, but provides the analytical power of high end systems. To achieve this, we try to combine the advantages of time of flight IMS (TOF-IMS) and field asymmetric IMS (FAIMS) by inserting a chamber with an alternating electrical field into the drift tube of a PCB based TOF-IMS.

 

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ESI-IMS

Bild zum Projekt ESI-IMS

Kurzbeschreibung:

Aim of this research project is the detection and analysis of pesticide and drug residues present in ground and surface water. Electrospray ionization (ESI) is a commonly used ionization method for the analysis of liquids. We coupled an electrospray ionization source with a 75mm desolvation tube to our high resolution ion mobility spectrometer with a 75mm drift tube length. One major advantage of our setup is that the desolvation region of the ESI-IMS can be heated separately from the drift region. With this setup we reach e.g. a resolving power of R=100 for tetraalkylammonium halides and at a water content of 50% and after 2s of averaging a LOD of 4 µg/l for bentazon.

 

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Nano-Q

Bild zum Projekt Nano-Q

Förderung durch:

This project is sponsored by the Federal Ministry of Education and Research. (13XP5011B)

Kurzbeschreibung:

Aim of this cooperation project is the development of a mercury sensor system for personal air monitoring (PAM). The sensor system is based on applications of nanogranular materials. The major tasks are the construction of a mercury test bench for the adjustment of lowest mercury concentrations and the characterization of the mercury sensors.

 

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Ultra high resolution ion mobility spectrometry

Bild zum Projekt Ultra high resolution ion mobility spectrometry

Förderung durch:

This research is founded by the German Research Foundation (DFG)

Kurzbeschreibung:

The aim of this research is the development of an ion mobility spectrometer with a resolving power above 300 and limits of detection in the pptv range for measurement times of less than a second. Furthermore, the performance using various non-radioactive ion sources such as X-ray and UV sources, electrospray ionization as well as non-radioactive electron emitters is being investigated. With a resolving power of 250 even for small, single-charged ions, the current setup is at the moment the highest resolving ion mobility spectrometer worldwide and the first device to separate isotopologues.

 

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Ion-selective ppb-level gas sensor

Bild zum Projekt Ion-selective ppb-level gas sensor

Förderung durch:

This research is founded by the German Research Foundation(DFG)

Kurzbeschreibung:

The objective of this work is the development of a fast ion-selective ppb-level gas sensor based on pulsed atmospheric pressure chemical ionization and ion-ion-recombination kinetics. The major tasks are the characterization of the ion generation and ion-ion-recombination kinetics of gas mixtures with various analytes and concentrations. Further, the measurement data should be analyzed by appropriate pattern recognition algorithm.

 

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Shutterless IMS

Bild zum Projekt Shutterless IMS

Kurzbeschreibung:

The use of non-radioactive electron sources for ionizing the target analytes in Ion Mobility Spectrometers (IMS) can lead to new application options. For example, our electron source can be operated in a fast pulsed mode. By optimizing the geometric parameters and developing fast control electronics, we can achieve very short electron pulses for ionization with high intensities, and an adjustable pulse width of down to a few nanoseconds. This results in small ion packets at simultaneously high ion densities. By omitting the separate reaction chamber the ion packet can be generated directly at the beginning of the drift tube with only slight reduction in resolving power. Thus, the complex and costly shutter mechanism and electronics can also be omitted, which leads to a simple low cost IMS-system with a pulsed non-radioactive source, and a resolving power of 70 to 80.

 

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X-Ray Ion Mobility Spectrometer

Bild zum Projekt X-Ray Ion Mobility Spectrometer

Kurzbeschreibung:

For the ionization of gaseous samples, most ion mobility spectrometers employ radioactive ionization sources, e.g. containing 63Ni or 3H. Besides legal restrictions, radioactive materials have the disadvantage of a constant radiation with predetermined intensity. The aim of this research project is the realization and characterization of an X-ray IMS. Therefore, the 3H-source of our previously described compact high resolution IMS was replaced by a commercially available X-ray source. The realized setup maintains the high resolving power of R = 100 at a drift length of 75 mm and shows very good detection limits in the low pptv-range.

 

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Electromagnetic sensors for biochemical and biomedical applications

Bild zum Projekt Electromagnetic sensors for biochemical and biomedical applications

Kurzbeschreibung:

The major advantages of electromagnetic sensors are a compact design and cost effective realization. In different projects, sensors (e.g. coaxial measuring chambers, open-ended coaxial probes, coplanar probes, split-ring resonators) are designed and tailored to the requirements of specific applications. Current research includes measurements of brain tissue humidity in forensic examinations, noninvasive cell growth monitoring in single use bioreactors and detection of ethanolamine in fluid.

 

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Electromagnetic Simulations

Bild zum Projekt Electromagnetic Simulations

Kurzbeschreibung:

Electromagnetic simulations offer an insight into electric and magnetic field distributions or radiation characteristics of arbitrary structures, such as transmission lines, filters or antennas. Furthermore, determination of scattering parameters allows a description of transmission and reflection characteristic of electromagnetic waves. In current research, electromagnetic simulations with CST Microwave Studio are used, e.g. to support the design process of electromagnetic sensors.

 

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Identification of bacteria regarding metabolic products

Bild zum Projekt Identification of bacteria regarding metabolic products

Kurzbeschreibung:

Bacteria emit characteristic metabolic products. Using our ultra-high sensitive GC-APCI-MS, we are able to distinguish between different bacterial species and even different bacterial type strains.

 

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Non-invasive monitoring of bacterial growth in a bioreactor

Bild zum Projekt Non-invasive monitoring of bacterial growth in a bioreactor

Kurzbeschreibung:

In order to monitor dynamic changes in the exhaust gas composition of a bioreactor, our GC-IMS can be used. The system enables automatic sampling and detection of more than 100 compounds during every exhaust gas analysis.

 

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Ultra-sensitive atmospheric pressure chemical ionization mass spectrometry

Bild zum Projekt Ultra-sensitive atmospheric pressure chemical ionization mass spectrometry

Kurzbeschreibung:

In various applications trace gas concentrations in the ppt-range need to be detected in less than a second. Due to an increasing number of contaminants present at ppt-levels ultra-high sensitivity also requires excellent selectivity. Our approach to achieve this combination is to push highly selective mass spectrometer (MS) towards extreme sensitivities by coupling atmospheric pressure ionization sources (API) to time-of-flight mass spectrometers (ToF-MS). For example, a radioactive Tritium (³H) ionization source coupled to a Bruker micrOTOF II leading to ppq detection for protonated Acetone.

 

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Nanosensors

Bild zum Projekt Nanosensors

Kurzbeschreibung:

Many medical, biotechnological, safety and security applications require highly sensitive and selective sensors. Due to special properties of nano-objects, they can be used to optimize the analytical performance of existing sensors systems. Therefore, we are working on new sensor solutions using nanoparticles, nanowire or other nano-objects.

 

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Ultra-fast polarity switching ion mobility spectrometer

Bild zum Projekt Ultra-fast polarity switching ion mobility spectrometer

Kurzbeschreibung:

It is well known that depending on their gas phase energetic properties, different substances may form positive ions, negative ions or even ions of both polarities in some cases. Thus, non-targeted measurements or measurements aiming to monitor a variety of substances require analyzing ions of both polarities, e.g. in GC-IMS applications. In this project, an ion mobility spectrometer which is able to perform a polarity switch in less than 10 ms has been developed. This allows switching the measurement polarity after every spectrum, thus enabling real-time monitoring of ions of both polarities with a single drift tube and obviating the need for expensive twin drift tubes.

 

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Ion Mobility Spectrometer with a Resolving Power of R = 100

Bild zum Projekt Ion Mobility Spectrometer with a Resolving Power of R = 100

Kurzbeschreibung:

For the analysis of gas mixtures at atmospheric pressure we developed a compact drift tube ion mobility spectrometer (IMS) with a length of about 100 mm and an outer diameter of 30 mm. Furthermore, the resolving power belongs to R=100. The IMS can be operated in a temperature range between room temperature and 100°C. Due to the institute’s own machine shop it is also possible to rapidly modify the IMS for many applications. For example, the ionization region can modified, thus several ionization sources can be compared. Of course, the detection region can be modified to adapt the IMS to a mass spectrometer.

 

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Development of an in-line measurement system for blood parameters for individualized patient therapy during dialysis

Bild zum Projekt Development of an in-line measurement system for blood parameters for individualized patient therapy during dialysis

Förderung durch:

This work is supported by the German Federal Ministry of Education and Research (BMBF) under the grant 13GW0085B.

Kurzbeschreibung:

The goal of this work is to enable a continuous detection of the relevant blood parameters during dialysis treatment, such as electrolyte and urea concentration. This allows a real-time monitoring during the treatment. Thus, the dialysis can be controlled precisely and a more gentle treatment for the patient can be achieved. For this purpose, a novel electrochemical and electromagnetic in-line sensor concept will be developed to determine the blood parameters in extracorporeal circuits.

 

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TOXI-triage

Bild zum Projekt TOXI-triage

Förderung durch:

European Union’s Horizon 2020 research and innovation programme under grant agreement No 653409

Kurzbeschreibung:

TOXI-triage project address the operational; technological; ethical and societal dimensions of CBRN response and recovery, and importantly the economic base from which sustainable CBRN and multiuse systems are derived.

 

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IMS MS coupling

Bild zum Projekt IMS MS coupling

Förderung durch:

This research is founded by the German Research Foundation (DFG)

Kurzbeschreibung:

The analysis an unknown gas mixture and the subsequent identification of the compounds by using an ion mobility spectrometer (IMS) is a difficult task. Due to several ion species, e.g. hybrid ions, can be generated in the ionization process the classification are not reliable. Coupling an IMS to a mass spectrometer (MS) offers the analysis of the occurring peaks in the IMS spectrum. Using our setup it is possible to transfer single ion clouds (peaks) of the generated IMS spectra into the MS where a corresponding mass spectrum is generated.

 

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