Session: Current and Future Challenges in Analytical Spectrometry III

Session Chair: Prof. Dr. Carsten Engelhard, Prof. Dr. Kerstin Leopold
English

Cascade Lasers in Chem/Bio Sensing:Quo Vadis?

Boris Mizaikoff, Ulm University
Owing to the recent technological advances in mid-infrared (3-15 µm; MIR) laser technology, especially cascade laser spectroscopy (CSL) has evolved into a state-of-the-art tool for the selective and sensitive quantification of trace analytes in liquid, solid, and gaseous state in a wide variety of sensing scenarios. High output power, narrow linewidths, single-mode operation, low power consumption, broad tunability and compact dimensions are just some of the most outstanding features of cascade lasers. Since their introduction in the mid 1990ies, quantum cascade lasers (QCL) and interband cascade lasers (ICL) have rapidly matured and have established themselves among the most important contemporary MIR laser light sources. In this presentation, we will discuss state-of-the-art sensing platforms that benefit from cascade lasers combined with miniaturized and integrated optical platforms providing direct access to molecule-specific information. With in-situ sensing strategies e.g., in harsh environments or point-of-care diagnostics in medicine becoming more prevalent, detection schemes that do not require reagents or labeled constituents facilitate localized on-site analysis close to real-time. However, decreasing the analytically probed volume may adversely affect the associated analytical figures of merit such as the signal-to-noise-ratio, the representativeness of the sample, or the fidelity of the obtained analytical signal. Consequently, the guiding paradigm for the miniaturization of optical diagnostic devices specifically for medical/clinical applications should be creating chem/bio sensing platforms that smartly capitalize on advantageous features of integrated photonics. Quo vadis? We will discuss which way these technologies may go in future specifically facilitating compact and robust MIR diagnostic platforms for label-free chem/bio sensing and medical diagnostics in a variety of application scenarios.
English

Cascade Lasers in Chem/Bio Sensing:Quo Vadis?

Boris Mizaikoff, Ulm University
Owing to the recent technological advances in mid-infrared (3-15 µm; MIR) laser technology, especially cascade laser spectroscopy (CSL) has evolved into a state-of-the-art tool for the selective and sensitive quantification of trace analytes in liquid, solid, and gaseous state in a wide variety of sensing scenarios. High output power, narrow linewidths, single-mode operation, low power consumption, broad tunability and compact dimensions are just some of the most outstanding features of cascade lasers. Since their introduction in the mid 1990ies, quantum cascade lasers (QCL) and interband cascade lasers (ICL) have rapidly matured and have established themselves among the most important contemporary MIR laser light sources. In this presentation, we will discuss state-of-the-art sensing platforms that benefit from cascade lasers combined with miniaturized and integrated optical platforms providing direct access to molecule-specific information. With in-situ sensing strategies e.g., in harsh environments or point-of-care diagnostics in medicine becoming more prevalent, detection schemes that do not require reagents or labeled constituents facilitate localized on-site analysis close to real-time. However, decreasing the analytically probed volume may adversely affect the associated analytical figures of merit such as the signal-to-noise-ratio, the representativeness of the sample, or the fidelity of the obtained analytical signal. Consequently, the guiding paradigm for the miniaturization of optical diagnostic devices specifically for medical/clinical applications should be creating chem/bio sensing platforms that smartly capitalize on advantageous features of integrated photonics. Quo vadis? We will discuss which way these technologies may go in future specifically facilitating compact and robust MIR diagnostic platforms for label-free chem/bio sensing and medical diagnostics in a variety of application scenarios.
English

Cascade Lasers in Chem/Bio Sensing:Quo Vadis?

Boris Mizaikoff, Ulm University
Owing to the recent technological advances in mid-infrared (3-15 µm; MIR) laser technology, especially cascade laser spectroscopy (CSL) has evolved into a state-of-the-art tool for the selective and sensitive quantification of trace analytes in liquid, solid, and gaseous state in a wide variety of sensing scenarios. High output power, narrow linewidths, single-mode operation, low power consumption, broad tunability and compact dimensions are just some of the most outstanding features of cascade lasers. Since their introduction in the mid 1990ies, quantum cascade lasers (QCL) and interband cascade lasers (ICL) have rapidly matured and have established themselves among the most important contemporary MIR laser light sources. In this presentation, we will discuss state-of-the-art sensing platforms that benefit from cascade lasers combined with miniaturized and integrated optical platforms providing direct access to molecule-specific information. With in-situ sensing strategies e.g., in harsh environments or point-of-care diagnostics in medicine becoming more prevalent, detection schemes that do not require reagents or labeled constituents facilitate localized on-site analysis close to real-time. However, decreasing the analytically probed volume may adversely affect the associated analytical figures of merit such as the signal-to-noise-ratio, the representativeness of the sample, or the fidelity of the obtained analytical signal. Consequently, the guiding paradigm for the miniaturization of optical diagnostic devices specifically for medical/clinical applications should be creating chem/bio sensing platforms that smartly capitalize on advantageous features of integrated photonics. Quo vadis? We will discuss which way these technologies may go in future specifically facilitating compact and robust MIR diagnostic platforms for label-free chem/bio sensing and medical diagnostics in a variety of application scenarios.
English

Molecular images and differentiation of isomers based on mass spectrometry of biological samples

Bernhard Spengler, Universität Gießen
Detection of lipids, peptides, drugs and metabolites in tissues and cells is a key issue for the understanding of biological processes. Mass spectrometry imaging is an advantageous tool in this context, as it allows to visualize compounds with cellular resolution in an untargeted and unbiased approach, i.e. without having to label expected compounds prior to analysis. Recent improvements in spatial resolution and sensitivity will be reported for the socalled atmospheric-pressure scanning microprobe MALDI mass spectrometry imaging technique (AP-SMALDI MSI). The method has gained significant attention especially due to its capability to disclose morphologic distributions of substances in complex biological samples with high sensitivity under ambient pressure, thus avoiding vacuuminduced analyte losses or morphological artefacts [1]. High resolution in mass and space has been used to derive distinct molecular information from sub-cellular structures. We developed dedicated imaging ion sources for the combination with orbital trapping mass spectrometers to image drugs, metabolites, phospholipids and peptides. A new high-speed system now includes autofocusing and 3D-surface analysis with a lateral resolution down to 1.4 µm per pixel [2]. The method allows to visualize bioactive compounds in e.g. human, animal, and plant tissue, in vectors of infection or in parasites, from planar sections or from non-planar 3D surfaces [3]. The high mass resolution and accuracy of the orbital trapping mass spectrometers at the same time allow to clearly assign and distinguish metabolites within the highly complex samples. Beyond that, MS/MS imaging in combination with structure-specific derivatization allows to characterize and identify known or unknown compounds down to the isomeric level, e.g. regarding double-bond positions in lipids.
English

Molecular images and differentiation of isomers based on mass spectrometry of biological samples

Bernhard Spengler, Universität Gießen
Detection of lipids, peptides, drugs and metabolites in tissues and cells is a key issue for the understanding of biological processes. Mass spectrometry imaging is an advantageous tool in this context, as it allows to visualize compounds with cellular resolution in an untargeted and unbiased approach, i.e. without having to label expected compounds prior to analysis. Recent improvements in spatial resolution and sensitivity will be reported for the socalled atmospheric-pressure scanning microprobe MALDI mass spectrometry imaging technique (AP-SMALDI MSI). The method has gained significant attention especially due to its capability to disclose morphologic distributions of substances in complex biological samples with high sensitivity under ambient pressure, thus avoiding vacuuminduced analyte losses or morphological artefacts [1]. High resolution in mass and space has been used to derive distinct molecular information from sub-cellular structures. We developed dedicated imaging ion sources for the combination with orbital trapping mass spectrometers to image drugs, metabolites, phospholipids and peptides. A new high-speed system now includes autofocusing and 3D-surface analysis with a lateral resolution down to 1.4 µm per pixel [2]. The method allows to visualize bioactive compounds in e.g. human, animal, and plant tissue, in vectors of infection or in parasites, from planar sections or from non-planar 3D surfaces [3]. The high mass resolution and accuracy of the orbital trapping mass spectrometers at the same time allow to clearly assign and distinguish metabolites within the highly complex samples. Beyond that, MS/MS imaging in combination with structure-specific derivatization allows to characterize and identify known or unknown compounds down to the isomeric level, e.g. regarding double-bond positions in lipids.
English

Molecular images and differentiation of isomers based on mass spectrometry of biological samples

Bernhard Spengler, Universität Gießen
Detection of lipids, peptides, drugs and metabolites in tissues and cells is a key issue for the understanding of biological processes. Mass spectrometry imaging is an advantageous tool in this context, as it allows to visualize compounds with cellular resolution in an untargeted and unbiased approach, i.e. without having to label expected compounds prior to analysis. Recent improvements in spatial resolution and sensitivity will be reported for the socalled atmospheric-pressure scanning microprobe MALDI mass spectrometry imaging technique (AP-SMALDI MSI). The method has gained significant attention especially due to its capability to disclose morphologic distributions of substances in complex biological samples with high sensitivity under ambient pressure, thus avoiding vacuuminduced analyte losses or morphological artefacts [1]. High resolution in mass and space has been used to derive distinct molecular information from sub-cellular structures. We developed dedicated imaging ion sources for the combination with orbital trapping mass spectrometers to image drugs, metabolites, phospholipids and peptides. A new high-speed system now includes autofocusing and 3D-surface analysis with a lateral resolution down to 1.4 µm per pixel [2]. The method allows to visualize bioactive compounds in e.g. human, animal, and plant tissue, in vectors of infection or in parasites, from planar sections or from non-planar 3D surfaces [3]. The high mass resolution and accuracy of the orbital trapping mass spectrometers at the same time allow to clearly assign and distinguish metabolites within the highly complex samples. Beyond that, MS/MS imaging in combination with structure-specific derivatization allows to characterize and identify known or unknown compounds down to the isomeric level, e.g. regarding double-bond positions in lipids.
English

Multi-Method Combinations of La-Icp-Ms for Spatially-Resolved Chemical Analysis

Johanna Irrgeher, Montanuniversität Leoben
Imaging techniques are essential for the characterization of materials and are used in almost all fields of science at the macro- and microscopic level. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has established itself as an important method of qualitative and quantitative element and isotope ratio analysis. By combining elemental and isotopic mass spectrometry via split-stream, different chemical information on solid samples can now be acquired simultaneously at the same sampling spot. An example is the simultaneous measurement of Sr isotopes and elemental distribution patterns on fish otoliths to map the migration of fish in natural ecosystems. [1] In addition, it is possible to obtain the spectroscopic information of the laser for the direct quantitative analysis of elements by LIBS (Laser induced breakdown spectroscopy) and the determination of isotope ratios by LAMIS (laser ablation molecular isotopic spectrometry). Although LIBS has higher detection limits than LAICP-MS, it allows very rapid analysis of major elements and elements that are difficult to access using LA-ICP-MS (e.g., H, C, N, O or F). In this context, for example, the elemental distribution of technological-critical elements (TCE) in leaves was determined in order to arrive at a risk assessment of TCE in urban agglomerations. In another study, the combination of LIBS and LA-ICP-MS allowed to generate depth profiles along with 3-D-images of steel CRMs, visualizing different elemental composition of the surface compared to inner layers of the samples including H. Non-destructive spectroscopic methods (such as infrared spectroscopy (IR) or hyperspectral imaging (HSI)) prior to analysis by LA-ICP-MS allows to gain additional information based on molecular characteristics of a sample. By combining HSI and LAICP-MS, for example, the degradation state of historical bone materials was determined in order to be able to determine the Sr isotopic composition in biogenic bone material by means of LA-ICP-MS. [2] Another recent development is the combination of diffusive gradients in thin film (DGT) methods with LA-ICP-MS.[3] Here, analyte-selective gels can be used to map speciesspecific element distributions of labile (i.e. reversibly adsorbed) element fractions in complex environmental matrices. As an example, the spatial distribution of individual inorganic As species was measured in the rhizosphere of As hyperaccumulating plants. In the field of materials science, the combination of DGT LA-ICP-MS and planar optodes enabled the micrometer-scale visualization of spatio-temporal Mg flux dynamics in the surface corrosion of biodegradable Mg implants.
English

Multi-Method Combinations of La-Icp-Ms for Spatially-Resolved Chemical Analysis

Johanna Irrgeher, Montanuniversität Leoben
Imaging techniques are essential for the characterization of materials and are used in almost all fields of science at the macro- and microscopic level. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has established itself as an important method of qualitative and quantitative element and isotope ratio analysis. By combining elemental and isotopic mass spectrometry via split-stream, different chemical information on solid samples can now be acquired simultaneously at the same sampling spot. An example is the simultaneous measurement of Sr isotopes and elemental distribution patterns on fish otoliths to map the migration of fish in natural ecosystems. [1] In addition, it is possible to obtain the spectroscopic information of the laser for the direct quantitative analysis of elements by LIBS (Laser induced breakdown spectroscopy) and the determination of isotope ratios by LAMIS (laser ablation molecular isotopic spectrometry). Although LIBS has higher detection limits than LAICP-MS, it allows very rapid analysis of major elements and elements that are difficult to access using LA-ICP-MS (e.g., H, C, N, O or F). In this context, for example, the elemental distribution of technological-critical elements (TCE) in leaves was determined in order to arrive at a risk assessment of TCE in urban agglomerations. In another study, the combination of LIBS and LA-ICP-MS allowed to generate depth profiles along with 3-D-images of steel CRMs, visualizing different elemental composition of the surface compared to inner layers of the samples including H. Non-destructive spectroscopic methods (such as infrared spectroscopy (IR) or hyperspectral imaging (HSI)) prior to analysis by LA-ICP-MS allows to gain additional information based on molecular characteristics of a sample. By combining HSI and LAICP-MS, for example, the degradation state of historical bone materials was determined in order to be able to determine the Sr isotopic composition in biogenic bone material by means of LA-ICP-MS. [2] Another recent development is the combination of diffusive gradients in thin film (DGT) methods with LA-ICP-MS.[3] Here, analyte-selective gels can be used to map speciesspecific element distributions of labile (i.e. reversibly adsorbed) element fractions in complex environmental matrices. As an example, the spatial distribution of individual inorganic As species was measured in the rhizosphere of As hyperaccumulating plants. In the field of materials science, the combination of DGT LA-ICP-MS and planar optodes enabled the micrometer-scale visualization of spatio-temporal Mg flux dynamics in the surface corrosion of biodegradable Mg implants.
English

Multi-Method Combinations of La-Icp-Ms for Spatially-Resolved Chemical Analysis

Johanna Irrgeher, Montanuniversität Leoben
Imaging techniques are essential for the characterization of materials and are used in almost all fields of science at the macro- and microscopic level. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has established itself as an important method of qualitative and quantitative element and isotope ratio analysis. By combining elemental and isotopic mass spectrometry via split-stream, different chemical information on solid samples can now be acquired simultaneously at the same sampling spot. An example is the simultaneous measurement of Sr isotopes and elemental distribution patterns on fish otoliths to map the migration of fish in natural ecosystems. [1] In addition, it is possible to obtain the spectroscopic information of the laser for the direct quantitative analysis of elements by LIBS (Laser induced breakdown spectroscopy) and the determination of isotope ratios by LAMIS (laser ablation molecular isotopic spectrometry). Although LIBS has higher detection limits than LAICP-MS, it allows very rapid analysis of major elements and elements that are difficult to access using LA-ICP-MS (e.g., H, C, N, O or F). In this context, for example, the elemental distribution of technological-critical elements (TCE) in leaves was determined in order to arrive at a risk assessment of TCE in urban agglomerations. In another study, the combination of LIBS and LA-ICP-MS allowed to generate depth profiles along with 3-D-images of steel CRMs, visualizing different elemental composition of the surface compared to inner layers of the samples including H. Non-destructive spectroscopic methods (such as infrared spectroscopy (IR) or hyperspectral imaging (HSI)) prior to analysis by LA-ICP-MS allows to gain additional information based on molecular characteristics of a sample. By combining HSI and LAICP-MS, for example, the degradation state of historical bone materials was determined in order to be able to determine the Sr isotopic composition in biogenic bone material by means of LA-ICP-MS. [2] Another recent development is the combination of diffusive gradients in thin film (DGT) methods with LA-ICP-MS.[3] Here, analyte-selective gels can be used to map speciesspecific element distributions of labile (i.e. reversibly adsorbed) element fractions in complex environmental matrices. As an example, the spatial distribution of individual inorganic As species was measured in the rhizosphere of As hyperaccumulating plants. In the field of materials science, the combination of DGT LA-ICP-MS and planar optodes enabled the micrometer-scale visualization of spatio-temporal Mg flux dynamics in the surface corrosion of biodegradable Mg implants.
English

Towards Metal Speciation Imaging

Uwe Karst, Universität Münster
Imaging methods have become apparent as important tools in many application areas of the Metallomics field, including studies on the distribution and the effects of (metallo)pharmaceuticals in the body, on the role of nutrients in plants, animals and humans and on toxic effects of compounds and nanoparticles. To further improve the information gained from imaging experiments, the combination of complementary imaging techniques to solve complex questions has strongly increased in recent years. Combinations of chemical imaging methods including MALDI-MS, µXRF or LA-ICP-MS or of chemical in vitro methods with medical in vivo imaging methods including CT or MRI provide valuable additional information. Within this presentation, strategies and examples for the combined use of several chemical and medical imaging techniques are highlighted, with a particular focus on complementary methods to LA-ICP-MS. These include the analysis of tattoo dyes in human skin samples and of the adduct formation of metal species with proteins in various tissues of animal or human origin. One major goal of this talk is to present future strategies for spatially resolved speciation analysis based on complementary molecular and elemental imaging techniques. In particular, ion mobility spectrometry (IMS) coupled to MALDI-MS imaging will be introduced as a powerful tool for the analysis of metal species in biological samples. Requirements for sample preparation and quantification will be discussed as well as possibilities and remaining challenges in this field.
English

Towards Metal Speciation Imaging

Uwe Karst, Universität Münster
Imaging methods have become apparent as important tools in many application areas of the Metallomics field, including studies on the distribution and the effects of (metallo)pharmaceuticals in the body, on the role of nutrients in plants, animals and humans and on toxic effects of compounds and nanoparticles. To further improve the information gained from imaging experiments, the combination of complementary imaging techniques to solve complex questions has strongly increased in recent years. Combinations of chemical imaging methods including MALDI-MS, µXRF or LA-ICP-MS or of chemical in vitro methods with medical in vivo imaging methods including CT or MRI provide valuable additional information. Within this presentation, strategies and examples for the combined use of several chemical and medical imaging techniques are highlighted, with a particular focus on complementary methods to LA-ICP-MS. These include the analysis of tattoo dyes in human skin samples and of the adduct formation of metal species with proteins in various tissues of animal or human origin. One major goal of this talk is to present future strategies for spatially resolved speciation analysis based on complementary molecular and elemental imaging techniques. In particular, ion mobility spectrometry (IMS) coupled to MALDI-MS imaging will be introduced as a powerful tool for the analysis of metal species in biological samples. Requirements for sample preparation and quantification will be discussed as well as possibilities and remaining challenges in this field.
English

Towards Metal Speciation Imaging

Uwe Karst, Universität Münster
Imaging methods have become apparent as important tools in many application areas of the Metallomics field, including studies on the distribution and the effects of (metallo)pharmaceuticals in the body, on the role of nutrients in plants, animals and humans and on toxic effects of compounds and nanoparticles. To further improve the information gained from imaging experiments, the combination of complementary imaging techniques to solve complex questions has strongly increased in recent years. Combinations of chemical imaging methods including MALDI-MS, µXRF or LA-ICP-MS or of chemical in vitro methods with medical in vivo imaging methods including CT or MRI provide valuable additional information. Within this presentation, strategies and examples for the combined use of several chemical and medical imaging techniques are highlighted, with a particular focus on complementary methods to LA-ICP-MS. These include the analysis of tattoo dyes in human skin samples and of the adduct formation of metal species with proteins in various tissues of animal or human origin. One major goal of this talk is to present future strategies for spatially resolved speciation analysis based on complementary molecular and elemental imaging techniques. In particular, ion mobility spectrometry (IMS) coupled to MALDI-MS imaging will be introduced as a powerful tool for the analysis of metal species in biological samples. Requirements for sample preparation and quantification will be discussed as well as possibilities and remaining challenges in this field.