Application Notes: Biological, Medical, and Clinical
Effects of Particle Size and Column Length on IEX Charge Variant Analysis of Monoclonal Antibodies
February 1st 2013A commercially available monoclonal antibody was analyzed via two different particle sizes (5 ?m and 3 ?m) and column lengths (100 mm and 30 mm) to investigate their effects on resolution and the ability to increase sample throughput.
Direct Analysis of Drugs in Biofluids
Sample pretreatment is often a time consuming and labor-intensive step which can be a restricting factor for the rapid analysis. This is especially true for the analysis of drugs in biofluids containing many interfering matrices.
Isolation and LC–MS Characterization of Illicit Bath Salts in Urine
February 1st 2013In this article, the analysis of bath salts (phenethylamine and cathionone compounds) from urine samples is demonstrated using polymeric solid phase extraction (SPE) sample preparation followed by HILIC chromatographic analysis with TOF-MS detection. HILIC chromatographic conditions on the Ascentis? Express HILIC phase are used for fast, high-resolution separation of nine synthetic bath salts.
Hyaluronic Acid (Polysaccharides)
February 1st 2013Hyaluronic acid (HA) is a ubiquitous, very high molar mass polysaccharide that has been of particular importance in opthalmic surgery. HA acts as a molecular "shock-absorber" and stabilizer for cells and its visco-elastic properties are valuable for separating tissue and maintaining shape.
Effects of Small Particle Size on SEC Characterization of Monoclonal Antibodies
February 1st 2013A commercially available monoclonal antibody was analyzed via three different particle sizes (5 ?m, 3 ?m, and 2 ?m) to investigate the effects of particle size on resolution and the ability to increase sample throughput.
Ultra-fast Protein Separations and High Efficiency Peptide Profiling with Agilent LC Columns
September 1st 2012Rapid and highly resolved chromatographic separations of proteins are becoming increasingly important to meet the growing demands for faster analyses, greater reliability and overall increased column performance. Additionally, highly selective and efficient separations for peptide and impurity profiling have grown among the biopharmaceutical industry, with an ever increasing need to obtain greater peak capacities.
Rapid Improvements for LC–MS-MS Analysis Using the New Phree? Phospholipid Removal Plates
September 1st 2012When performing LC–MS-MS analysis, phospholipids are perhaps one of the most troublesome components of bioanalytical samples. The presence of phospholipids not only reduces the column lifetime and sensitivity but can also cause a phenomenon known as ion suppression.
Separation of mAb Isoforms Using Controlled pH Gradients and Ion Exchange Chromatography Columns
September 1st 2012Monoclonal antibody isoforms differ in modifications of individual amino acid side chains, or the N- or C-terminus. Typical modifications are deamidation, phosphorylation, acetylation, methylation, oxidation, or glycosylation. Fast separation of monoclonal antibody isoforms is important for profiling and mass spectrometric determination. Isoforms may differ in biological activity and stability, making a thorough characterization and quantification of the isoforms necessary to ensure consistent product quality.
Analysis of phosphate compounds with the Agilent 1260 Infinity Bio-inert Quaternary LC System
September 1st 2012This application note shows that unspecific reaction of adenosine triphosphate can be completely prevented due to the iron- and steel-free design using the Agilent 1260 Infinity Bio-inert Quaternary LC System.
70-min Amino Acid Analysis of Physiological Samples
September 1st 2012Pickering Laboratories specializes in the manufacturing of cation-exchange columns and eluants for amino acid analysis. Post-column derivatization with Ninhydrin offers unmatched selectivity and reproducibility of the analysis for most challenging matrixes.
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.
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.
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.
Practical Advice for High Throughput Ion Exchange Separations using Non-porous Particles
June 1st 2012Ion exchange is a perfect technique for analyzing large biomolecules such as proteins, peptides and oligonucleotides. These complex compounds contain numerous components (amino acids, nucleotides, glycans etc.) many of which possess a charged side chain or backbone.