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Next-Generation Mid-Infrared Chemical and Biological Sensors: Combining Quantum Cascade Lasers with Thin-Film and Hollow WaveguidesMid-infrared (MIR, 3-20 µm) sensor platforms are increasingly adopted in chem/bio analytics, and applied in areas ranging from process monitoring to medical diagnostics. Due to the inherent access to molecule-specific fingerprints via well-pronounced fundamental vibrational, rotational, and roto-vibrational transitions, quantitative information at ppm to ppb concentration levels and beyond is achievable in solids, liquids, and gases. In particular, the combination of quantum cascade lasers (QCLs) with correspondingly tailored waveguide technologies serving as optical transducers – thin-film waveguides for liquid/solid phase analysis, and substrate-integrated hollow waveguides for gaseous samples – facilitates miniaturizable and integrated optical chem/bio sensors and diagnostics applicable in, e.g., exhaled breath analysis, food safety, and environmental monitoring.
Latest:
Next-Generation Mid-Infrared Chemical and Biological Sensors: Combining Quantum Cascade Lasers with Thin-Film and Hollow WaveguidesMid-infrared (MIR, 3-20 µm) sensor platforms are increasingly adopted in chem/bio analytics, and applied in areas ranging from process monitoring to medical diagnostics. Due to the inherent access to molecule-specific fingerprints via well-pronounced fundamental vibrational, rotational, and roto-vibrational transitions, quantitative information at ppm to ppb concentration levels and beyond is achievable in solids, liquids, and gases. In particular, the combination of quantum cascade lasers (QCLs) with correspondingly tailored waveguide technologies serving as optical transducers – thin-film waveguides for liquid/solid phase analysis, and substrate-integrated hollow waveguides for gaseous samples – facilitates miniaturizable and integrated optical chem/bio sensors and diagnostics applicable in, e.g., exhaled breath analysis, food safety, and environmental monitoring.
Latest:
Next-Generation Mid-Infrared Chemical and Biological Sensors: Combining Quantum Cascade Lasers with Thin-Film and Hollow WaveguidesMid-infrared (MIR, 3-20 µm) sensor platforms are increasingly adopted in chem/bio analytics, and applied in areas ranging from process monitoring to medical diagnostics. Due to the inherent access to molecule-specific fingerprints via well-pronounced fundamental vibrational, rotational, and roto-vibrational transitions, quantitative information at ppm to ppb concentration levels and beyond is achievable in solids, liquids, and gases. In particular, the combination of quantum cascade lasers (QCLs) with correspondingly tailored waveguide technologies serving as optical transducers – thin-film waveguides for liquid/solid phase analysis, and substrate-integrated hollow waveguides for gaseous samples – facilitates miniaturizable and integrated optical chem/bio sensors and diagnostics applicable in, e.g., exhaled breath analysis, food safety, and environmental monitoring.
Latest:
Next-Generation Mid-Infrared Chemical and Biological Sensors: Combining Quantum Cascade Lasers with Thin-Film and Hollow WaveguidesMid-infrared (MIR, 3-20 µm) sensor platforms are increasingly adopted in chem/bio analytics, and applied in areas ranging from process monitoring to medical diagnostics. Due to the inherent access to molecule-specific fingerprints via well-pronounced fundamental vibrational, rotational, and roto-vibrational transitions, quantitative information at ppm to ppb concentration levels and beyond is achievable in solids, liquids, and gases. In particular, the combination of quantum cascade lasers (QCLs) with correspondingly tailored waveguide technologies serving as optical transducers – thin-film waveguides for liquid/solid phase analysis, and substrate-integrated hollow waveguides for gaseous samples – facilitates miniaturizable and integrated optical chem/bio sensors and diagnostics applicable in, e.g., exhaled breath analysis, food safety, and environmental monitoring.
Latest:
Next-Generation Mid-Infrared Chemical and Biological Sensors: Combining Quantum Cascade Lasers with Thin-Film and Hollow WaveguidesMid-infrared (MIR, 3-20 µm) sensor platforms are increasingly adopted in chem/bio analytics, and applied in areas ranging from process monitoring to medical diagnostics. Due to the inherent access to molecule-specific fingerprints via well-pronounced fundamental vibrational, rotational, and roto-vibrational transitions, quantitative information at ppm to ppb concentration levels and beyond is achievable in solids, liquids, and gases. In particular, the combination of quantum cascade lasers (QCLs) with correspondingly tailored waveguide technologies serving as optical transducers – thin-film waveguides for liquid/solid phase analysis, and substrate-integrated hollow waveguides for gaseous samples – facilitates miniaturizable and integrated optical chem/bio sensors and diagnostics applicable in, e.g., exhaled breath analysis, food safety, and environmental monitoring.
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Recent Advances in TERS Imaging of 2D MaterialsWebinar Date/Time: Tue, Dec 10, 2024 2:00 PM EST
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Merck: The Do’s and Don’ts of Working with Purified WaterFollow these simple tips to avoid common handling errors that could result in contamination and impact your sensitive analyses.
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Spectroscopy Market: Weathering the Storm and on the Path to RecoveryAfter weathering the economic downturn of 2009, the analytical instrumentation industry's business appears to have made a U-turn in 2010, primarily due to the burgeoning requirements of the life sciences and pharmaceutical industries and substantial demands from the chemical and petrochemical industries, in addition to growing environmental concerns. The analytical instrumentation industry managed the economic downturn better than most other industries even though some of its primary revenue streams, such as the replacement market, were hurt by procurement postponements.
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Frontiers of NIR ImagingThis review explores the latest advancements in near-infrared (NIR) imaging technology, detailing its diverse applications such as tracking solvent diffusion in polymers, portable analysis systems in pharmaceuticals, high-speed polymer monitoring, and NIR imaging for fish embryo development research.
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Advanced Antibody–Drug Conjugate Structural Characterization by Sheathless Capillary Electrophoresis–Tandem Mass Spectrometry Using Complementary ApproachesAntibody drug conjugates (ADCs) are an emerging category of biotherapeutic products based on monoclonal antibodies (mAbs) coupled to powerful cytotoxic drugs. The production of ADCs entails the formation of species with different number of conjugates drugs. The heterogeneity of ADCs species add to the complexity originating from the mAbs microvariability. Sheathless capillary electrophoresis-mass spectrometry (sheathless CE-MS) using complementary approaches was used to perform a detail characterization of brentuximab vedotin (Adcetris, Seattle Genetics). Sheathless CE-MS instrument used as nanoESI infusion platform was involved to perform the intact and middle-up analysis in native MS conditions. The nanoESI infusion approaches enabled estimation of the average drug to antibody ratio (DAR) alongside to drug load distribution. Sheathless CZE-MS/MS method developed was used to obtain from a single injection the characterization of the amino acid sequence with complete sequence coverage. In addition glycosylation and drug-loaded peptides could be identified from MS/MS spectra revealing robust information regarding their localizations and abundances. Drug-loaded peptide fragmentation mass spectra study demonstrated drug-specific fragments reinforcing the identifications confidence. Results reveal the ability of sheathless CZE-MS/MS method to characterize ADCs primary structure in a single experiment.
Latest:
Advanced Antibody–Drug Conjugate Structural Characterization by Sheathless Capillary Electrophoresis–Tandem Mass Spectrometry Using Complementary ApproachesAntibody drug conjugates (ADCs) are an emerging category of biotherapeutic products based on monoclonal antibodies (mAbs) coupled to powerful cytotoxic drugs. The production of ADCs entails the formation of species with different number of conjugates drugs. The heterogeneity of ADCs species add to the complexity originating from the mAbs microvariability. Sheathless capillary electrophoresis-mass spectrometry (sheathless CE-MS) using complementary approaches was used to perform a detail characterization of brentuximab vedotin (Adcetris, Seattle Genetics). Sheathless CE-MS instrument used as nanoESI infusion platform was involved to perform the intact and middle-up analysis in native MS conditions. The nanoESI infusion approaches enabled estimation of the average drug to antibody ratio (DAR) alongside to drug load distribution. Sheathless CZE-MS/MS method developed was used to obtain from a single injection the characterization of the amino acid sequence with complete sequence coverage. In addition glycosylation and drug-loaded peptides could be identified from MS/MS spectra revealing robust information regarding their localizations and abundances. Drug-loaded peptide fragmentation mass spectra study demonstrated drug-specific fragments reinforcing the identifications confidence. Results reveal the ability of sheathless CZE-MS/MS method to characterize ADCs primary structure in a single experiment.
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Matrix-Assisted Laser Desorption-Ionization Imaging Mass Spectrometry for Direct Tissue AnalysisA summary of the most recent advances in sample preparation, instrumentation, and data-processing techniques for MALDI-IMS
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Direct Enantiomer-Selective Mass Spectrometry of Chiral Mixtures by Mass-Selected Photoelectron Circular DichroismSimultaneous, enantiomer-specific identification of chiral molecules in multi-component mixtures is extremely challenging. Many established techniques for single-component analysis fail to provide selectivity in multi-component mixtures and lack sensitivity for dilute samples. Mass spectrometry is chirally blind, and so cannot directly distinguish the two enantiomers of chiral molecules. Here we discuss how enantiomers may be differentiated by Mass Spectrometry correlated with PhotoElectron Circular Dichroism (MS-PECD) using an electron–ion coincidence imaging spectrometer. Following an ionizing circular polarized laser pulse, ions and electrons are detected in coincidence on their respective time- and position sensitive detectors. The MS-PECD asymmetry measured on electrons tagged by the mass of their corresponding parent ion directly reveals that the compound with identified mass is chiral without the need for any prior enantiomeric separation or enantiomer-selective complexation. MS-PECD enables direct enantiomeric excess measurement of multi-component chiral samples in a table-top mass spectrometer.
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Direct Enantiomer-Selective Mass Spectrometry of Chiral Mixtures by Mass-Selected Photoelectron Circular DichroismSimultaneous, enantiomer-specific identification of chiral molecules in multi-component mixtures is extremely challenging. Many established techniques for single-component analysis fail to provide selectivity in multi-component mixtures and lack sensitivity for dilute samples. Mass spectrometry is chirally blind, and so cannot directly distinguish the two enantiomers of chiral molecules. Here we discuss how enantiomers may be differentiated by Mass Spectrometry correlated with PhotoElectron Circular Dichroism (MS-PECD) using an electron–ion coincidence imaging spectrometer. Following an ionizing circular polarized laser pulse, ions and electrons are detected in coincidence on their respective time- and position sensitive detectors. The MS-PECD asymmetry measured on electrons tagged by the mass of their corresponding parent ion directly reveals that the compound with identified mass is chiral without the need for any prior enantiomeric separation or enantiomer-selective complexation. MS-PECD enables direct enantiomeric excess measurement of multi-component chiral samples in a table-top mass spectrometer.
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Appropriate Use of Mass Spectrometry in Clinical and Metabolic ResearchUsing examples from our analysis of L-carnitine and acyl-L-carnitines, we give specific guidance for the use of mass spectrometry in quantitative analysis, as applied to clinical research and clinical pharmacology. We focus on quantitative accuracy and analytical selectivity as keys to successful implementation of mass spectrometric methods in clinical applications
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Appropriate Use of Mass Spectrometry in Clinical and Metabolic ResearchUsing examples from our analysis of L-carnitine and acyl-L-carnitines, we give specific guidance for the use of mass spectrometry in quantitative analysis, as applied to clinical research and clinical pharmacology. We focus on quantitative accuracy and analytical selectivity as keys to successful implementation of mass spectrometric methods in clinical applications
Latest:
Appropriate Use of Mass Spectrometry in Clinical and Metabolic ResearchUsing examples from our analysis of L-carnitine and acyl-L-carnitines, we give specific guidance for the use of mass spectrometry in quantitative analysis, as applied to clinical research and clinical pharmacology. We focus on quantitative accuracy and analytical selectivity as keys to successful implementation of mass spectrometric methods in clinical applications
Latest:
Appropriate Use of Mass Spectrometry in Clinical and Metabolic ResearchUsing examples from our analysis of L-carnitine and acyl-L-carnitines, we give specific guidance for the use of mass spectrometry in quantitative analysis, as applied to clinical research and clinical pharmacology. We focus on quantitative accuracy and analytical selectivity as keys to successful implementation of mass spectrometric methods in clinical applications
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Rapid Determination of the Peroxide Value of Edible Oil by Handheld NIR Spectroscopy in Combination with Wavelength Variables Selection and PLS CalibrationA PLS model was built with optimized wavelength variables generated by a competitive adaptive reweighted sampling (CARS) algorithm, enabling the use of handheld NIR spectroscopy to rapidly detect peroxide values in oil.
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Raman Spectroscopy of Carbonaceous Materials: A Concise ReviewA critical review focused on the Raman spectroscopy of carbonaceous materials and of polymer-based nanocomposites that contain carbonaceous (nano) materials as fillers
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Matrix-Assisted Laser Desorption-Ionization Imaging Mass Spectrometry for Direct Tissue AnalysisA summary of the most recent advances in sample preparation, instrumentation, and data-processing techniques for MALDI-IMS
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Comparison of Extracts from Dry and Alcohol-Steamed Root of Polygonatum kingianum (Huang Jing) by Sub-2-µm–LC–TOF-MSMost plants used in traditional Chinese medicine must be processed before their medicinal usage; hence the effective ingredients may differ from those in the freshly harvested plant extracts. In this work, we present a fast and generic approach using sub-2-?m liquid chromatography–time-of-flight–mass spectrometry (sub-2-?m-LC–TOF-MS) coupled with multivariate statistical data analysis to systematically profile ingredient changes between fresh and processed samples of huang jing.
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Determination of Major Components in Hemodialysis Solutions with the Avio 550 Max ICP-OESThis work demonstrates the ability of PerkinElmer's Avio® 550 Max ICP-OES to provide highly accurate determinations of major components in hemodialysis solutions
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Mass Spectrometry Advances FossilomicsFossilomics uses MS to extract amino acid sequence information from subpicomole quantities of protein and peptide fragments that remain in certain fossil samples. The sequences are compared to databases and validated with search statistics and high-confidence sequences. The validated sequences can then be used to place the fossils on the evolutionary tree.
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Minimizing Method-Induced Deamidation and Isomerization During Antibody Characterization to Ensure Optimal Understanding of Product Quality AttributesAccurate evaluation of chemical modifications such as asparagine deamidation and aspartic acid isomerization is an essential component of comprehensive characterization of therapeutic monoclonal antibodies (mAbs). When located in the complementarity determining regions (CDRs), these modifications can cause a loss of function, impacting product efficacy and safety, resulting in the designation of the modification as a critical quality attribute. However, artifactual modifications can be introduced by analytical procedures, and distinguishing modifications as either critical quality attributes or method-induced artifacts is an important objective for product development. Conventional peptide mapping coupled with ultrahigh-resolution mass spectrometry offers advanced capabilities for definitive characterization of protein therapeutics. However, experimental conditions such as digestion time and pH can influence the observed level of chemical modifications, usually leading to over-estimation. In this work, a new peptide mapping method was developed specifically for mAb characterization that employs optimal enzyme pH for robustness, but short digestion times and time-course elements to minimize and monitor deamidation/isomerization, respectively, allowing a more accurate assessment of potential CDR sequence liabilities.
Latest:
Minimizing Method-Induced Deamidation and Isomerization During Antibody Characterization to Ensure Optimal Understanding of Product Quality AttributesAccurate evaluation of chemical modifications such as asparagine deamidation and aspartic acid isomerization is an essential component of comprehensive characterization of therapeutic monoclonal antibodies (mAbs). When located in the complementarity determining regions (CDRs), these modifications can cause a loss of function, impacting product efficacy and safety, resulting in the designation of the modification as a critical quality attribute. However, artifactual modifications can be introduced by analytical procedures, and distinguishing modifications as either critical quality attributes or method-induced artifacts is an important objective for product development. Conventional peptide mapping coupled with ultrahigh-resolution mass spectrometry offers advanced capabilities for definitive characterization of protein therapeutics. However, experimental conditions such as digestion time and pH can influence the observed level of chemical modifications, usually leading to over-estimation. In this work, a new peptide mapping method was developed specifically for mAb characterization that employs optimal enzyme pH for robustness, but short digestion times and time-course elements to minimize and monitor deamidation/isomerization, respectively, allowing a more accurate assessment of potential CDR sequence liabilities.
Latest:
Minimizing Method-Induced Deamidation and Isomerization During Antibody Characterization to Ensure Optimal Understanding of Product Quality AttributesAccurate evaluation of chemical modifications such as asparagine deamidation and aspartic acid isomerization is an essential component of comprehensive characterization of therapeutic monoclonal antibodies (mAbs). When located in the complementarity determining regions (CDRs), these modifications can cause a loss of function, impacting product efficacy and safety, resulting in the designation of the modification as a critical quality attribute. However, artifactual modifications can be introduced by analytical procedures, and distinguishing modifications as either critical quality attributes or method-induced artifacts is an important objective for product development. Conventional peptide mapping coupled with ultrahigh-resolution mass spectrometry offers advanced capabilities for definitive characterization of protein therapeutics. However, experimental conditions such as digestion time and pH can influence the observed level of chemical modifications, usually leading to over-estimation. In this work, a new peptide mapping method was developed specifically for mAb characterization that employs optimal enzyme pH for robustness, but short digestion times and time-course elements to minimize and monitor deamidation/isomerization, respectively, allowing a more accurate assessment of potential CDR sequence liabilities.
Latest:
Minimizing Method-Induced Deamidation and Isomerization During Antibody Characterization to Ensure Optimal Understanding of Product Quality AttributesAccurate evaluation of chemical modifications such as asparagine deamidation and aspartic acid isomerization is an essential component of comprehensive characterization of therapeutic monoclonal antibodies (mAbs). When located in the complementarity determining regions (CDRs), these modifications can cause a loss of function, impacting product efficacy and safety, resulting in the designation of the modification as a critical quality attribute. However, artifactual modifications can be introduced by analytical procedures, and distinguishing modifications as either critical quality attributes or method-induced artifacts is an important objective for product development. Conventional peptide mapping coupled with ultrahigh-resolution mass spectrometry offers advanced capabilities for definitive characterization of protein therapeutics. However, experimental conditions such as digestion time and pH can influence the observed level of chemical modifications, usually leading to over-estimation. In this work, a new peptide mapping method was developed specifically for mAb characterization that employs optimal enzyme pH for robustness, but short digestion times and time-course elements to minimize and monitor deamidation/isomerization, respectively, allowing a more accurate assessment of potential CDR sequence liabilities.
Latest:
Minimizing Method-Induced Deamidation and Isomerization During Antibody Characterization to Ensure Optimal Understanding of Product Quality AttributesAccurate evaluation of chemical modifications such as asparagine deamidation and aspartic acid isomerization is an essential component of comprehensive characterization of therapeutic monoclonal antibodies (mAbs). When located in the complementarity determining regions (CDRs), these modifications can cause a loss of function, impacting product efficacy and safety, resulting in the designation of the modification as a critical quality attribute. However, artifactual modifications can be introduced by analytical procedures, and distinguishing modifications as either critical quality attributes or method-induced artifacts is an important objective for product development. Conventional peptide mapping coupled with ultrahigh-resolution mass spectrometry offers advanced capabilities for definitive characterization of protein therapeutics. However, experimental conditions such as digestion time and pH can influence the observed level of chemical modifications, usually leading to over-estimation. In this work, a new peptide mapping method was developed specifically for mAb characterization that employs optimal enzyme pH for robustness, but short digestion times and time-course elements to minimize and monitor deamidation/isomerization, respectively, allowing a more accurate assessment of potential CDR sequence liabilities.
