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A Mixed-Mode Stationary Phase for the Structural Analysis of Labelled N-Glycans Using LC–MS–MSThis article describes the analysis of fluorescently labelled N-glycans released from proteins by liquid chromatography–mass spectrometry (LC–MS).
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Improved Performance of Ultrahigh-Pressure Liquid Chromatography–Mass Spectrometry (UHPLC–MS) Hyphenated SystemsAn UHPLC–MS research prototype instrument was built to improve the resolution power and the usability of conventional LC–MS hyphenated instruments for routine analyses in pharmaceutical applications.
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Intelligent Automation of LC–MS Analysis for the Characterization of Compound LibrariesThis article reports an approach to applying intelligent automation for high-throughput LC}MS analysis of compound libraries using Microsoft Visual Basic software.
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Using Compact Mass Spectrometry for Detection and Quantitation of Cannabis-Related CompoundsCompact mass spectrometry, in combination with suitable sample introduction techniques-such as the atmospheric solids analysis probe, thin-layer chromatography, and classical liquid chromatography techniques-can be used effectively for the detection and quantification of cannabinoids and pesticides in cannabis-related material and contraband.
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High-Resolution Mass Spectrometry: An Ideal Analytical Tool for Drug Metabolism StudiesA method using HR-MS systems to characterize the structures of metabolites is presented. The result is a general workflow for metabolism studies in drug discovery and development.
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Ultrahigh-Performance Liquid Chromatography–Mass Spectrometry in LipidomicsAn analytical method for the global profiling of molecular lipids in biological samples, with particular emphasis on the plasmalogen lipids, is described.
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Haloacetic Acid Analysis Using Two-Dimensional Matrix-Elimination Ion ChromatographyThe disinfectants commonly used to treat public drinking water can react with naturally occurring organic and inorganic matter in the source water to form disinfection byproducts such as haloacetic acids. Here, we describe the use of two-dimensional matrix-elimination ion chromatography (MEIC) for haloacetic acid analysis. This method minimizes the impact of matrix ions.
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"Critical to Quality" Measurements of Protein Aggregation in BiopharmaceuticalsIn biopharmaceutical development the stability of biological molecules in drug formulations is important. This article describes three different approaches to the measurement and quantification of aggregates in protein solutions, and highlights the range of information that each technique can provide about the sample.
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Generic UHPLC Method for the Simultaneous Analysis of Compounds with a Wide Range of PolaritiesAppropriate analytical methods are required to evaluate the presence, metabolism, degradation, and removal of specific compounds in complex mixtures. There is an increasing demand to analyze samples with a wide range of polarities in a variety of applications, including environmental analysis, biomarker discovery, and proteomics. Multiple analyses on complementary columns are often needed to cover the separation of all compounds with a large difference in polarity. This article describes a generic method involving an ultrahigh-pressure liquid chromatography (UHPLC) system equipped with two external switching valves to connect hydrophilic interaction liquid chromatography (HILIC) and reversed-phase LC columns in series for the sequential analysis of polar and apolar compounds. The method was successfully applied to separate 32 pharmaceutical compounds with a wide range of polarities, which could be useful for analyzing pharmaceutical compounds in the environment.
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How Reversed-Phase Liquid Chromatography WorksThis tutorial on reversed-phase LC explains the role of solvent, chain conformation, solute position, and retention dynamics.
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Analysis of Four Phthalate Monoesters in Human Urine Using Liquid Chromatography Tandem Mass SpectrometryA fast, sensitive and accurate quantitative method was developed using HPLC–MS–MS for analysis of phthalate metabolites in urine samples.
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Molecular Weight Analysis of Glatiramer Acetate and Related Compounds by Size-Exclusion Chromatography with Multi-Angle Light Scattering Detection (SEC-MALS)A method was developed for the molecular weight characterization of heterogeneous polymer mixtures, such as heparins and glatiramer acetate, noting that single molecular structures are not adequate for creating a molecular weight calibration curve. That limitation is overcome in this work, which demonstrates method validation and application to process samples.
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Application of Pyrolysis–Gas Chromatography–Mass Spectrometry for the Identification of Polymeric MaterialsThe pyrolysis–GC–MS method enables direct analysis of solid or liquid polymers without sample pretreatment, as illustrated here for various materials, including a dental filling material and a car wrapping foil.
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Development of an Ultrasensitive LC–MS-MS Method for Determination of 5-Fluorouracil in Mouse Plasma5-Fluorouracil (5-FU) is a low-molecular-weight anticancer drug in clinical use for several solid tumors in humans. Currently, the most widely used methodology for 5-FU quantitation is liquid chromatography–tandem mass spectrometry (LC–MS-MS) with either liquid–liquid extraction (LLE), protein precipitation, or a combination of both as sample cleanup procedures.
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Tools for Simulation and Optimization of Separations in Ion ChromatographyComputer-based methods can simulate separations for a wide variety of analytes, columns, and eluents.
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HILIC and Its Applications for Biotechnology, Part IIThe modern usage and specific applications of HILIC for two other major classes of analytes - glycopeptides and glycoproteins - are discussed.
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LC–MS Identification of Wax Esters in Cloudy Canola OilCanola largely contains unsaturated fatty acids, thus rendering it clear in most cases after extraction and refining.
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LC–MS Identification of Wax Esters in Cloudy Canola OilCanola largely contains unsaturated fatty acids, thus rendering it clear in most cases after extraction and refining.
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Carbon Nanotubes: Applications in Chromatography and Sample PreparationThe latest applications for carbon nanotubes in chromatography and sample preparation are outlined.
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Rapid Compound Identification from Crude Oil Enabled by Fourier Transform Ion Cyclotron Resonance Mass SpectrometryThe analysis of crude oil by means of different atmospheric pressure ionization (API) techniques is described. Crude oil is analysed without any separation prior to API-Fourier transform mass spectrometry. The use of a quadrupole/hexapole device to selectively enhance a certain mass range is demonstrated. Automated generation of molecular formulas from accurate mass measurements enables rapid compound identification.
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Determination of Phytohormones in Plant Extracts Using In-matrix Ethyl Chloroformate Derivatization and DLLME–GC–MSA fast and simple sample preparation method for the simultaneous determination of 11 phytohormones in plants by GC–MS has been developed.
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Determination of Halogens and Sulphur in Complex MatricesThis article presents a method that combines combustion digestion and ion chromatography into a single analysis (combustion ion chromatography [CIC]) making it possible to detect halogens and sulphur in complex matrices. The method is suitable for use in a wide range of application areas.
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Sensitive Determination of Polycyclic Aromatic Hydrocarbons in Tap WaterThis Application Note demonstrates the sensitive and rapid determination of Polycyclic Aromatic Hydrocarbons (PAHs) in tap water using the Agilent 1200 Infinity Series Online SPE Solution.
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Determination of 2-Hydroxy-4-(methylthio)butanoic Acid in Bovine Serum and Sea WaterSimple, sensitive, rapid, selective, and precise reversed-phase liquid chromatography (LC), electrospray ionization mass spectrometry (ESI-MS), and tandem MS (ESI-MS-MS) methods were developed and validated for the determination of 2-hydroxy-4-(methylthio)-butanoic acid (HMTBA) in bovine serum and sea water matrix. HMTBA is the ?-hydroxy analog of the sulfur-containing amino acid methionine and is extensively used as a methionine supplement in poultry and bovine feed.
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A New Method for Quality by Design Robust Optimization in Liquid ChromatographyA new method to optimize liquid chromatography (LC) methods using a Quality by Design (QbD) approach is presented. This method is based on the use of design of experiments (DOE) and independent component analysis (ICA) to accurately estimate the modeled responses (that is, the retention times at the beginning, the apex, and the end) of each peak, even for coeluted peaks. This method was applied to the optimization of the separation of nine compounds in a mixture, yielding the design space and the demonstration of robustness of the method.
