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Monoclonal antibodies (mAbs) are being developed at an explosive rate and have attracted great interest from both smaller biotech firms and big pharmaceutical companies. Developing mAbs and next-generation antibody-drug conjugates (ADCs) is highly demanding in many ways. From an analytical perspective, handling mAbs and ADCs presents many new challenges. This article describes how size-exclusion chromatography (SEC) combined with high-resolution mass spectrometry (HRMS) can be applied to the detailed characterization of mAbs and ADCs. [ABSTRACT FROM AUTHOR]

The article examines the use of an automated process in online peak fractionation and reduction of therapeutic antibodies using subsequent quadrupole time-of-flight mass spectrometry (QTOF-MS) characterization. Aspartic acid or asparagine residues in the light and heavy chain result in succinimide under acidic conditions. Characterization of charge and size variants is needed to produce the product knowledge that forms the basis for critical quality attribute (CQA) assessment.

Fluorescence polarization (FP) is a highly regarded technique for studying drug-protein interactions, but has limited value regarding protein mixtures. As a novel approach to drug target discovery, the possibility of combining FP with liquid chromatography (LC) was explored. Nondenaturing protein LC principles such as size-exclusion chromatography (SEC), hydrophobic interaction chromatography (HIC), and ion exchange chromatography (IEX) were found to be orthogonal and compatible with FP because the mobile phases used do not negatively affect detection. For simple protein mixtures, the SEC/HIC/IEX-FP approach was able to identify tankyrase as the target of a triazole-based inhibitor of the Wnt signaling pathway, which is heavily associated with colon cancer. However, the total peak capacity of the three LC dimensions was not sufficient to resolve at cell-proteome level, calling for higher resolution of intact proteins to enable stand-alone drug target discovery with LC and FP. [ABSTRACT FROM AUTHOR]

The article offers brief information on several liquid chromatography (LC) columns and accessories including the Jordi Resolve GPC columns from Jordi Labs LLC, the LW-803 columns from Shodex, and Luna Omega from Phenomenex.

Complete characterization of low-molecular-weight polyether polyol formulations that are often simultaneously heterogeneous in composition, molecular weight, and architecture can be a daunting task. This article describes the hyphenation of size-exclusion chromatography (SEC) to mass spectrometry (MS) as a promising approach to characterize complex polyether polyol formulated systems. Hyphenating these techniques signifi cantly reduces ion overlap in MS spectra and results in a versatile and powerful tool better able to unravel these complex mixtures. This work details some of the experimental considerations and advances made with the development of SEC-MS methods, including interfacing the techniques, method optimization, and best approaches to data processing routines. Attention will be given to fast and efficient SEC separation and reduction of multiple charging effects. [ABSTRACT FROM AUTHOR]

The determination of the chemical composition distribution of acrylic resins is not straightforward. Pyrolysis-gas chromatography (py-GC) analyses of acrylic resins can yield problems in the recovery of the hydroxyl and acid functional fragments that form. To overcome these problems pyrolysis-liquid chromatography (py-LC) can be performed. This article describes how the validation and quantification of hydroxyl acrylate-, hydroxyl methacrylate-, hydroxyl propylacrylate-, and hydroxyl propylmethacrylate resins by py-LC is performed. Furthermore, off-line size-exclusion chromatography (SEC) coupled to py-LC is performed to determine the chemical composition distribution over the molecular weight distribution of a core-shell waterborne acrylic resin. [ABSTRACT FROM AUTHOR]

The recent trends in column technology for reversed-phase liquid chromatography (LC), size-exclusion chromatography (SEC), ion-exchange chromatography (IEX), and hydrophobic interaction chromatography (HIC) for analysis of biopharmaceuticals at the protein level is critically discussed. [ABSTRACT FROM AUTHOR]

In this instalment, we discuss fluorescence-detection size-exclusion chromatography (FSEC) technology and its implications in protein characterization, specifically the development and characterization of biologies. [ABSTRACT FROM AUTHOR]

The seven faux pas discussed here are common practices in high performance liquid chromatography (HPLC) that may no longer make sense because of improved technologies or other changes in modern HPLC. Therefore, careful consideration should be given to alternative approaches. [ABSTRACT FROM AUTHOR]

Field-flow fractionation (FFF) is a family of techniques that is increasingly used for separating and characterizing macromolecules. This review discusses recent advances in the characterization of biological, natural, and synthetic polymers. Applications of FFF are contrasted with size-exclusion chromatography to illustrate practical considerations when characterizing macromolecules. The use of different FFF fields allows separations based on size, mass, composition, and architecture. The open channel design and subsequent low shear rate is well suited for analyzing weakly bound complexes, highly branched polymers, high molar mass analytes, and aggregates. Other benefits of FFF that are highlighted in this paper include simplified sample preparation, flexibility in carrier fluid choice, and on-line removal of low-molecular-weight contaminants. [ABSTRACT FROM AUTHOR]

The article focuses on the establishment of size exclusion chromatography (SEC), a high performance liquid chromatography (HPLC) technique. It states that the method is used for the separation of macromolecules based on hydrodynamic volume. It says that a set of cross-linked dextran was synthesized in 1959 to show peptide and oligosaccharide size separation. It adds that Dow Chemical Co. acknowledged the significance of gel permeation chromatography (GPC) in their polymer business.

The article offers information on the problems and tools used to overcome problems encountered by the practicing spectrometrist in chemical industry in Europe. It states that the first decision by analysts is to determine the separation techniques to be used such as gas chromatography (GC), liquid chromatography (LC) and gel permeation chromatography. It notes that imaging mass spectrometry is a powerful technique for mapping the concentration of a compound.

The author discusses some novel extraction and chromatographic methods for environmental analysis. She says that levels of persistent organic pollutants (POPs) have been extensively measured in several parts of the environment. She cites that gel permeation chromatography (GPC) is a superior method for fast fractionation of the extracts. She notes that the development of both fast gas chromatographic (GC) liquid chromatographic (LC) techniques is important to lessen the analysis time, along with the development of faster preparation methods.

An interview with Hamesh Small, an American experimenter in separation science at U.S.-based chemical company Dow Chemical Co. is presented. When asked about his success in separation science, he refers on the development of ion chromatography and significant in scientific progress. He also mentions the method of molecular topology fractionation and gel permeation chromatography (GPC) in separation science.

Size-exclusion chromatography (SEC) and pyrolysis-gas chromatography (Py-GC) are commonly used to characterize copolymers. SEC is a powerful method to determine the molecular-weight distribution of polymers whereas Py-GC provides valuable information on their chemical composition. The combination of these two techniques coutd yield combined size and composition information for copolymers or polymer mixtures. A fully automated system was constructed to perform these two-dimensional (2D) characterizations. Several examples of the use of this new technique to comprehensively characterize polymers are described. [ABSTRACT FROM AUTHOR]

This article describes the development of a routine method to analyse epoxidized soybean oil (ESBO) in baby food based on a previous method devised by Castle et al. The aim was to simplify the work-up procedure to reduce the strain on the analytical equipment. The extraction procedure was miniaturized to improve handling, reduce the resources needed and simplify the method. After derivatization, the extracts were cleaned using gel permeation chromatography (GPC). A modified gas chromatography mass spectrometry (GC—MS) method using pulsed splitless injection was developed to determine the analyte. For quality control (QC), peak area ratios (PARs) were calculated and evaluated in terms of functionality under routine conditions. The method was validated according to EU regulations at a level of 20 ppm and showed high reproducibility. The miniaturized method proved to be applicable to all investigated baby food matrices and demonstrated the benefits of a GPC clean-up step to reduce strain on the apparatus and, therefore, increase sample turnaround significantly. [ABSTRACT FROM AUTHOR]

Size-exclusion chromatography (SEC) — also known as gel permeation chromatography (GPC) — is the standard technique used to characterize macromolecules in solution. In this article GPC is employed to measure membrane performance parameters such as retention behaviour, pore size and molar mass cut-off. This method relies on the filtration behaviour of the membranes. The applicability to different kinds of membranes is described. [ABSTRACT FROM AUTHOR]

The article presents information about several products related to gel permeation chromatography (GPC). Available from Viscotek are a range of GPC columns reportedly offering optimum column performance, reliability and long column lifetimes even under severe operating conditions. Polymer Laboratories Ltd. has launched a GPC system designed for operation from ambient to 50 °C. The PL-GPC 50 comprises a precision solvent delivery system with flow reproducibility of better than 0.1%, a manual injection valve, a high performance differential refractive index detector, an integrated column oven and Cirrus GPC software as standard.

In this month's "GC Connections," the author examines the effects on retention times and peak shapes when a retention gap is added to a capillary column. [ABSTRACT FROM AUTHOR]

The article presents information on a variety of products introduced in analytical chemistry. Viscotek Corp. has announced the application of its proprietary triple detection gel permeation chromatography (GPC) technology to the characterization of a range of drug delivery systems including transdermal patches, capsules, and under-skin depots. Furthermore, Millipore Corp. has announced the availability of media to improve process efficiency and extend the life of fina filters. Also, from Amersham B osciences comes a fully integrated protein purification system for delivering automated, high-throughput, multi-step purification of proteins.

Examines the characteristics of size exclusion chromatographic (SEC) columns. Advances in commercially available column separation mechanism of SEC; Comparison of separation characteristics of SEC and high performance liquid chromatography; Ways in preventing enthalpic interactions between sample and packing.

The article presents an interview with Claudia Lohmann, independent polymer consultant to PSS-Polymer Standards Service USA Inc. Topics discussed include information regarding her works with macromolecules which involves focusing on factors like molar mass and chemical composition distribution; quality-control procedures used by PSS Labs; and analysis of samples using gel permeation chromatography (GPC) and interaction polymer chromatography (IPC).

The analysis toolbox for biotherapeutics contains many chromatographic techniques. When it comes to aggregation and fragmentation of a therapeutic protein, size exclusion chromatography (SEC) is the method of choice. Here we report the detection of absolute molecular weight of a recombinant protein sample using a UHPLC compatible Multi-Angle Light Scattering (MALS) detector for UHP-SEC-MALS analysis. [ABSTRACT FROM AUTHOR]

The article presents information about several literatures related to gel permeation chromatography. SCAT has released a brochure describing its range of safety caps for HPLC. The brochure covers caps for solvent supply, filtration of HPLC waste gases and safety accessories. Available from Gerstel is an analytical supplies catalogue for 2004/2005 providing a comprehensive and structured overview of consumable items required for optimal operation of Gerstel products. Available from Wyatt Co. is an application note on reversed-phase chromatography.

The analysis of organic polymers by gel permeation chromatography (GPC) is a mature analytical science. GPC was first developed as a method of analyzing the molecular weight distribution of polymers in the early 1960s and since then, it has become a widespread tool in polymer characterization laboratories. Perhaps surprisingly considering the interest in GPC as an analytical tool, the development of columns for the analysis of organic polymers has showed little recent progress. This article focuses on PlusPore, a new range of media for the analysis of organic polymers. Employing novel polymerization processes. PlusPore columns are manufactured to give unprecedented resolution coupled with a wide pore size distribution, making them state-of-the-art in GPC column design.

Evaluates the aspects of gel permeation chromatography or size exclusion chromatography. Problems on data reduction; Simplicity of the breed of pumps available to HPLC; Introduction of microparticulate columns.

Focuses on the method of determining the structure of polymers by gel permeation chromatography (GPC). Limitations on the use of GPC in the distribution of molecular masses; Utilization of light scattering and viscosity in GPC for the characterization of complex polymers; Approach to obtain molecular weight distributions and degree of polymer branching.

Phenol formaldehyde resins (PFR) are used in various industrial products because of their versatile properties. Thermoplastic and thermo-reactive resin types differ in the degree of remaining reactive groups and their molar mass distribution (MMD). We compared the MMDs of two phenolic resins by gel permeation chromatography (GPC). [ABSTRACT FROM AUTHOR]