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Molecular Weight Determination of LMWH SEC–MALS vs. SEC–UV-RI
September 1st 2012Low-molecular-weight heparins (LMWHs) are obtained by fractionation or depolymerization of natural heparins. They are defined as having a mass-average molecular weight of less than 8000 and for which at least 60% of the total weight has a molecular mass less than 8000.
Analysis of Intact Proteins on a Thermo Scientific Accucore 150 C4 HPLC Column
September 1st 2012This application note demonstrates the analysis of intact proteins using a Thermo Scientific Accucore 150-C4 (150 ? pore diameter) HPLC column. Analysis of six proteins ranging in mass from 6 to 45 kDa is carried out in 15 min with pressures compatible with conventional HPLC instrumentation.
Creation of a New IMS Analyzer Platform with High Resolving Power
September 1st 2012Ion mobility spectrometry (IMS) has become widely accepted for the detection of chemical warfare agents, explosives, and narcotics as well as for pharmaceutical quality control and pesticide screening of food. Most currently available commercial IMS units have a resolving power of 10–60.
Unique Effects of Two Mobile Phase Alcohols on the RegisPack CLA-1 Chiral Stationary Phase (CSP)
September 1st 2012Typical chiral stationary phase (CSP) screening paradigms utilize a single alcohol component as co-solvent in its mobile phase. Recent unexpected observations have demonstrated that mixed-alcohol mobile phases can enhance or even introduce peak resolution when none existed in a mono-alcohol system.
Fast Petroleum Hydrocarbons Analysis for Underground Storage Tank Monitoring
September 1st 2012Underground storage tanks (USTs) for various petroleum-based substances such as gasoline, diesel fuel, and fuel oil are monitored for leaks as authorized by the Resource Conservation and Recovery Act (RCRA).
Separation of 20 Amino Acids by Polymer-Based Amino HILIC Column
September 1st 2012Determination and quantification of amino acids are important in many fields. For the HPLC analysis of amino acids, cation exchange mode method has been used with post-column derivatization. Recently, use of reversed-phase mode method is also increasing. However, because of amino acids' hydrophilic nature, they are usually not well retained and have less selectivity by reversed-phase mode without pre-column derivatization steps. In contrast, HILIC mode is an ideal separation mode for hydrophilic compound analysis.
Enhanced Results of Diesel Range Organics Analysis with High-Temperature Gas Enhanced Chromatography
June 1st 2012Diesel range organic (DRO) compounds have boiling points similar to diesel fuel (C10–C28), ranging from 170–430 ?C. These heavy compounds are amenable to GC-FID analysis; however, important considerations should be taken to ensure reproducible results over repeated injections.
The Analysis of 1,4-Dioxane for EPA Method 522 and UCMR 3
June 1st 2012This application note will demonstrate the extraction of 1,4-dioxane from an aqueous matrix using option 1 of EPA Method 522 for 500 mL initial volume sample. It will make use of the SmartPrep Cartridge Extraction system to produce a valid initial demonstration of precision (IDP) and initial demonstration of accuracy (IDA).
Characterization of Polymeric Excipients by SEC-IR
June 1st 2012Excipients are pharmacologically inactive substances used as carrier and release controllers for active drug ingredients. A significant amount (30–80% solid) of polymeric excipients such as hydroxyl propyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC), hydroxypropyl methyl cellulose acetate succinate (HPMCAS), and povidone are used.
This application demonstrates that stringent sensitivity requirements for the detection of potentially harmful primary aromatic amines can be fulfilled when using an Agilent 1290 Infinity LC system equipped with the 1290 large volume injection kit.
Rapid LC–MS-MS Analysis of Heterocyclic Amines in Salmon
June 1st 2012Heterocyclic amines (HCAs) are a class of compounds that are formed when amino acids from meat proteins react with glucose and creatine under high-temperatures, as is associated with frying or grilling over an open flame (1–3). Studies have correlated the consumption of high levels of HCAs with an increased risk of some forms of cancer.
Detection of Protein Heterogeneity by HPLC
June 1st 2012Protein heterogeneity is generated by post-translational modification, decomposition, and a variety of other processes, including chemical modification, denaturation, and aggregation. Since antibodies and recombinant proteins are now widely used for therapeutic treatment, it is essential to evaluate their heterogeneity during development, stability testing, and in the quality control of the final product.
The need to increase the use of low valued co-products derived from the processing of sugar beets has prompted the investigation of the structure of the pectin extracted from sugar beet pulp. The characterization of sugar beet pectin is essential as it has the potential to be used in the production of industrial products, e.g., as an emulsifying agent in food systems.
Analytical Methods to Characterize and Quantify PEG and PEGylated Biopharmaceuticals
June 1st 2012Biotherapeutic peptides and proteins are often PEGylated (covalently bonded to polyethylene glycol polymers) to improve bioavailability, reduce immunogenicity, and extend circulating half-life (1). Achieving the desired properties for each application depends on optimizing the number and site of polymers attached, chain length, and the degree of chain branching.
Glycan Analysis using HPLC with Charged Aerosol Detection and MS Detectors
June 1st 2012Simple, rapid and accurate methods have been developed for the analysis of simple carbohydrates including mono- or disaccharides, or as fairly small glycans (6–11 residues) liberated from glycoproteins using charged aerosol detection combined with mass spectrometry techniques.
Molecular Weight Determination of Low-Molecular-Weight Heparins: SEC/MALS vs. SEC/UV-RI
June 1st 2012Low-molecular-weight heparins (LMWHs) are obtained by fractionation or depolymerization of natural heparins. They are defined as having a mass-average molecular weight of less than 8000 and for which at least 60% of the total weight has a molecular mass less than 8000.