Research Projects

[uncategorized]

• IMS MS coupling

  To identify the underlying ion species in ion mobility spectra, we couple our IMS devices to mass spectrometers (MS). A simple gated interface has been designed to transfer selected peaks of the ion mobility spectrum into the MS. By using this coupling, we investigate the occurring ion-molecule reactions in our ambient pressure DT-IMS or HiKE-IMS.

  Year: 2015

  Funding: This research is founded by the German Research Foundation (DFG)
• TOXI-triage

  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.

  Year: 2015

  Funding: European Union’s Horizon 2020 research and innovation programme under grant agreement No 653409
• Development of an in-line measurement system for blood parameters for individualized patient therapy during dialysis

  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.

  Year: 2016

  Funding: This work is supported by the German Federal Ministry of Education and Research (BMBF) under the grant 13GW0085B.
• Ion Mobility Spectrometer with a Resolving Power of R = 100

  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.

  Year: 2016
• Ultra-fast polarity switching ion mobility spectrometer

  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.

  Year: 2016

  © GEM
• Nanosensors

  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.

  Year: 2016
• Ultra-sensitive atmospheric pressure chemical ionization mass spectrometry

  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.

  Year: 2016
• Non-invasive monitoring of bacterial growth in a bioreactor

  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.

  Year: 2016
• Identification of bacteria regarding metabolic products

  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.

  Year: 2016
• Electromagnetic sensors for biochemical and biomedical applications

  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.

  Year: 2016
• X-Ray Ion Mobility Spectrometer

  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.

  Year: 2016
• Shutterless IMS

  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.

  Year: 2016
• Ion-selective ppb-level gas sensor

  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.

  Year: 2016

  Funding: This research is founded by the German Research Foundation(DFG)
• Ultra high resolution ion mobility spectrometry

  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.

  Year: 2016

  Funding: This research is founded by the German Research Foundation (DFG)
• Field asymmetric time of flight ion mobility spectrometry

  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.

  Year: 2016

  Funding: 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
• Nano-Q

  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.

  Year: 2016

  Funding: This project is sponsored by the Federal Ministry of Education and Research. (13XP5011B)
• ESI-IMS

  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.

  Year: 2016
• Data acquisition software for ion mobility spectrometers

  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.

  Year: 2016
• Measurement electronics

  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.

  Year: 2016
• Non-radioactive electron sources for fast high sensitive sensor systems

  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.

  Year: 2016

  Funding: This work is supported by the German Federal Ministry of Education and Research (BMBF) under the grant 13N12820.
• Chemical ionization detector for gas chromatography

  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.

  Year: 2016
• High kinetic energy ion mobility spectrometry (HiKE-IMS)

  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

  Year: 2016

  Funding: This research is founded by the German Research Foundation (DFG)
• Closed gas loop, high-resolution IMS with gas chromatographic pre-separation for breath gas analysis

  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).

  Year: 2016
• FEM simulation of ion trajectories within ion mobility spectrometer or mass spectrometer

  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.

  Year: 2016
• Mercury vapor sensor

  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.

  Year: 2016
• Realtime monitoring of the position of a cochlea implant

  During the Implantation of cochlea implants trauma and irritation of the auditory canal tissue must be avoided. Aim of the work is the supply of a realtime monitoring of the position of a cochlea implant based on continuous impedance measurement between the implant electrodes during insertion.

  Year: 2017
• Electron capture detector with non-radioactive electron source

  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.

  Year: 2017
• High Pressure HiKE-IMS (HiP-HiKE-IMS)

  The above described HiKE-IMS is a powerful device for detecting low electron and proton affine substances invisible for conventional IMS. Typical cross sensitivities to e.g. water are significantly reduced and additional separation by alpha-function improves compound identification. By increasing the operating pressure, the system can be miniaturized, the power consumption reduced and the limits of detection significantly improved. Therefore, in this project, we develop optimized drift tubes based on PCBs, which are able to maintain high reduced field strengths at significantly increased pressures. Such a PCB-HiKE-IMS can be operated at 60 mbar with detections limits in the low ppbv level, e.g. for benzene even in the presence of high toluene and water concentrations. The resolving power for benzene is R = 100 at a drift length of 15 cm. The used vacuum pump is just 194 x 115 x 77 mm³.

  Year: 2017

  Funding: This work is supported by the German Federal Ministry of Education and Research (BMBF) under the grant 13N14469
• Early adequate sepsis therapy using ion mobility spectrometry based diagnostics

  Aim of this project is the development of an innovative method for rapid pathogen identification of sepsis patients by headspace analysis of standard blood cultures using gas chromatography ion mobility spectrometry (GC-IMS). In contrast to the current care situation this method should lead to a result after a few hours, while the analysis itself only takes a few minutes. For this purpose, we develop a dual polarity IMS with a non-radioactive ionization source being able to detect positive and negative ions simultaneously. This allows the analysis of both ion polarities with just a single GC run.

  Year: 2017

  Funding: This work is supported by the German Federal Ministry of Education and Research (BMBF) under the grant 13GW0191D
• Miniaturized ion mobility spectrometer

  Aiming for mobile and hand-held applications miniaturized ion mobility spectrometer drift tubes are required. With its outer dimensions of only 15 mm x 15 mm in cross section and an overall length of 56 mm, the mini-IMS is one of our smallest high-performance drift tube IMS with a resolving power of Rp = 63 and detection limits in the mid pptv-range for 1s of averaging. For easy integration, the miniaturized drift tube is designed to fit commercially available DIP sockets (7.62 mm row-to-row spacing, 34 pins with 2.54 mm pitch). This enables direct connection of the drift tube to the driver electronics. Different ionization sources (radioactive and non-radioactive) can be operated with this drift tube.

  Year: 2017
• ReCoWind (Reliable power Converters for Wind turbines) - Measurement and Modeling of Moisture Migration on Component and System Level

  In the framework of the ReCoWind project the failure causes of wind turbine’s power converters are investigated as well as appropriate countermeasures are worked out. Therefore, a combined top-down and bottom-up approach is applied in order to evaluate field studies of wind turbines’ failures and breakdowns, to carry out additional investigations and to work out the failure principles on the component and system level. The evaluation of a possible degradation processes due of corrosive or harmful gases respectively is one research topic of this subproject. The main focus is on the moisture migration to the power modules of the frequency converter, which is assumed to be most significant failure cause. Furthermore, an understanding for the temperature and moisture distribution in the power module (component level) and the power converter’s cabinet (system level) will be worked out. Hereby, the modelling of moisture migration and transport is necessary, as well as the development of measurement technology and sensors for moisture and temperature with a high spatial resolution. Based on the findings of power converters’ failure causes, appropriate countermeasures will be worked out, which could increase the reliability of wind turbine’s power converters.

  Year: 2018

  Funding: This Project is supported by the Federal Ministry for Economic Affairs and Climate Action (BMWK), Grant 0324336E
• MiniLAB

  The aim of the cooperation project MiniLAB is the development of a portable instrument for fast on-site monitoring and detection of pollutants in water based on nano high performance liquid chromatography (nano-HPLC) and electrospray ionization (ESI) ion mobility spectrometry (IMS). The main tasks of the subproject are the realization of a high voltage isolated data acquisition as well as the control of the ESI parameters during a run of a solvent gradient.

  Year: 2019

  Funding: Supported by the German Federal Ministry of Economics and Technology (BMWi) upon decision of the German Bundestag, Grant 20666 N
• Ion mobility spectrometry coupled to chip-based electrochromatography

  In this cooperation project with the group of Professor Belder from the Leipzig University a chip electrochromatography (ChEC) is coupled to a compact electrospray ion mobility spectrometer (ESI-IMS) from our group. The aim of this work is to characterize ESI-IMS as detector for chip based separation techniques. Furthermore, secondary ionization with APPI and APCI sources is implemented in the desolvation region of the ESI-IMS to enable the detection of compounds that cannot be ionized by electrospray.

  Year: 2019

  Funding: This research is founded by the German Research Foundation (DFG) (ZI 1288/9-1)
• New ionization sources and fast gas chromatography coupled to a mobile mass spectrometer for hazardous substance detection (GC-Plasma-TOF)

  Aim of this research project is a mobile system for fast detection of hazardous substances for first responder applications. For this purpose, a mobile mass spectrometer will be coupled to a fast gas chromatograph for fast analysis of complex samples. Furthermore, four different ionization methods will be employed to improve both substance identification and limits of detection. Our focus is the development of a new plasma source.

  Year: 2019

  Funding: Supported by the German Federal Ministry of Education and Research (BMBF), Grant 13N14888
• GC-IMS measurements of volatile anaesthetics

  This project focuses on all topics related to trigger-free anaesthesia for patients threatened by malignant hyperthermia. With our GC-IMS, especially medical devices and indoor air will be examined for traces of volatile anaesthetics. For example, these substances can be detected in an average concentration of 120 ppb in postanaesthesia care units.

  Year: 2020
• Electromagnetic Simulations

  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.

  Year: 2020
• Novel ion drift tube based on a composite material

  In this project, we have developed a simple manufacturing process for ion mobility spectrometer drift tubes based on a composite material in order to reduce the manufacturing effort. This composite material consists of alternating layers of metal sheets and insulator material, which are connected to each other in a mechanically stable and gastight manner. Furthermore, this approach allows the production of multiple ion drift tubes in parallel in just a few steps from a single piece of material, thus further reducing the manufacturing costs and efforts per unit. The photo shows a drift tube IMS made of such a composite material. With 38.1 mm drift length, only 15 mm × 15 mm cross-section and 57 mm in overall length (outer dimensions) it has high resolving power of Rp = 62 and detection limits in the pptv-range with averaging times of one second.

  Year: 2020
• GIDPROvis

  In GIDPROvis, two original breakthrough technologies - Gas Ion Distillation (GID) and Sequential Ion Processing (PRO) - provide live visualization (vis) of volatile chemicals in ambient environments giving humans access to a molecular world heretofore unseen. Molecular auras in GIDPROvis are delivered by small GIDPRO analyzers based on high speed separation of ions derived from individual chemicals and their identification using an emerging generation of ion analyzers.

  Year: 2020

  Funding: European Union’s Horizon 2020 FET Open programme under grant agreement No 899261
• HiKE IMS MS

  In this research project, the kinetics of ion-molecule reactions in the gas phase as a function of the effective ion temperature will be investigated using a high-energy ion mobility spectrometer (HiKE-IMS) with selective ion sources. In order to generate defined ion populations, a hollow cathode ion source compatible to the HiKE-IMS will be realized within the scope of this research project. In addition, an implementation of a laser ionization source in the ionization region of the HiKE-IMS is planned, in which the ionization of molecules is achieved by resonant multiphoton excitation. This will allow a detailed investigation of reaction rates and reaction rate constants.

  Year: 2021

  Funding: This research is founded by the German Research Foundation (DFG) (ZI 1288/8-2)