Application Notes: Biological, Medical, and Clinical

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.

In 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 (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.

LC–MS-MS has become an important tool to assess an individual's vitamin D status. Chromatographic resolution of the various homologs of vitamin D2 is necessary for accurate quantitation since several key metabolites are isobaric and not distinguishable by MS alone.

A 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.

Shimadzu

Tosoh Bioscience

Biotage AB Application Note

Tosoh Bioscience LLC

Biotage, LLC

Rapid 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.

When 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.

Monoclonal 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.

Thermo Scientific Application Note

This 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.

Pickering 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.

This 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.

Thermo Scientific Application Note

Determination 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.

Simple, 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.

Low-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.

Ion 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.

Selective cleavage of proteins by the enzyme trypsin helps characterize larger proteins. While MS provides structural information, quantitative analysis is often based on detection by UV at 214 nm.

Plant materials contain a wealth of information on plant viability and health. The analysis of the metabolite contents of the leaves of various plants has been informative in the comparison of organisms.

Phenomenex Application Note

Erythropoietin protein (EPO) is a glycoprotein hormone found in plasma. It is a cytokine for erythrocyte (red blood cell) precursors in the bone marrow.

A new 3.6 µm 100 Å HPLC–UHPLC column (Aeris PEPTIDE) has been introduced that is specifically designed to improve separations of peptide and peptide mapping applications.

Simultaneous HPLC analysis of neurotransmitters can be challenging due to the similarity of their structures.