All
Simple and Rapid MRM Method Development for Analyzing 288 Pesticides by GC–MS-MS
September 1st 2012Gas chromatography coupled with tandem mass spectrometry (GC–MS-MS) operated in MRM mode is a powerful technology for multi-residue analysis in complex food matrices. Good GC separation combined with MS-MS selectivity facilitates monitoring hundreds of MRM transitions within a short cycle time which allows for analysis of large number of compounds in complex food matrices. Nevertheless, MRM method development is time consuming and labor-intensive, which mainly comes from mapping retention time, MRM transition set-up and post-data processing.
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.
Synthesis Monitoring and Oligomeric Analysis of PEGylated Polymers
September 1st 2012New roles and applications in the areas of science and technology are continuously being found for synthetic polymers. Specifically, the use of synthetic polymers in medicine is growing, as these polymers offer unique and versatile platforms for applications such as implants, medical devices, surgical adhesives, drug delivery vesicles, and injectable polymer-drug conjugates (1,2). As the applications of synthetic polymers increases, there is a manifested need for methods to accurately and precisely characterize the materials.
2D Analysis of Thermoplastic Elastomers TPE
September 1st 2012Blockcopolymers such as SBS (styrene-butadiene-styrene) are an important product class and a typical example of complex polymers. In addition to the molar mass distribution, a chemical composition distribution may also be present in copolymers. While GPC–SEC is the established method for the determination of molar mass averages and distribution, gradient HPLC can be applied to separate based on chemical composition.
A Single-Column Capillary GC Application for the Determination of Benzene in Reformulated Gasoline
September 1st 2012The amount of benzene in gasoline is a concern because it is a known human carcinogen, and exposure to it has been linked to detrimental health effects. The challenge with the analysis lies in the complex composition of gasoline, which consists of hundreds of different compounds. Reformulated gasoline also contains additives to produce more complete combustion and subsequent lower emissions of harmful compounds.
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.
Accurate Determination of Tartrate in Drug Products in Just 10 Minutes
September 1st 2012Tolterodine, a quaternary ammonium compound, is used to treat urinary incontinence. To create the drug substance, tolterodine is paired with tartrate to form tolterodine tartrate. This drug substance can then be used to create drug products. One way to confirm the amount of a drug substance in a drug product is to assay for its counterion.
Rapid On-Line-SPE HPLC Determination of Carbofuran and Carbaryl in Tap and Environmental Waters
September 1st 2012N-Methylcarbamates are widely used agricultural pesticides. For their determination, reversed-phase high-performance liquid chromatography (RP-HPLC) with fluorescence detection following postcolumn derivatization, per U.S. EPA Methods 531.2 and 8318, is typically used.
High Precision Pesticide Analysis in Produce with GC Triple Quadrupole and U-SRM Mode
September 1st 2012Residuals of pesticides widely used in agriculture are monitored in foods for human consumption through the use of statutory maximum residue levels (MRLs). Regulation EC 396/2005 adopted in the European Union sets MRLs for over 500 pesticides in over 300 food commodities, many at a default value of 0.01 mg/kg (the typical routine analytical method limit of determination).
Automated Solid Phase Extraction (SPE) of Organochlorine Pesticides in Water
September 1st 2012Organochlorine pesticides are man-made organic chemicals with a history of wide spread use in both the United States as well as globally. Tending to be very persistent in the environment, they have found their way into sediments and drinking water supplies posing serious health risks. Organochlorines have a wide range of both acute and chronic health effects, including cancer, neurological damage, and birth defects. Many organochlorines are also suspected endocrine disruptors.
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.
Characterization of PLGA Using SEC–MALS-VIS
September 1st 2012Poly(lactic-co-glycolic acid) (PLGA) is a copolymer based on glycolic acid and lactic acid. The two monomer units are linked together by ester linkages and form linear polyester chains. The obtained product is biodegradable and biocompatible, and it is approved by the Food and Drug Administration (FDA) for production of various therapeutic devices as well as for drug delivery applications.
QuEChERS Sample Preparation for LC–MS-MS Determination of Avermectins in Meat and Milk
September 1st 2012Avermectins are 16-membered ring macrolide drugs that are used as veterinary antihelmintics. The lowest allowable limit for these compounds in food products is set based on worldwide safety evaluations. Regulatory MRLs for avermectins can vary worldwide but are generally in the ppb concentration range. The sensitive analysis of avermectins in food products such as milk and meat can be challenging due to their complex sample matrices.
Improved Resolution of Triazine Herbicides in Drinking Water and Wastewater
September 1st 2012Often used for weed control, triazine herbicides have been found to have detrimental environmental and health effects. Much debate has focused on the level at which these compounds negatively impact health. To monitor and control human exposure to these herbicides, regulatory bodies have established allowable limits of triazines in drinking and wastewater.
Fast Separation of Eleven Nitroaromatic Compounds on ZirChrom-CARB
September 1st 2012This technical bulletin details the separation of 11 closely related nitroaromatic compounds, namely RDX, HMX, Nitrobenzene, 2-Nitrotoluene, Tetryl, 2,6-Dinitrotoluene, 4-Nitrotoluene, 1,3-Dinitrobenzene, 2,4-Dinitrotoluene, 2-amino 4,6-dinitrotoluene, 1,3,5-Trinitrobenzene. Our customers have reported that similar separations on silica-based phases produce run times as long as 30 min. Here we report a method on ZirChrom?-CARB at a column temperature of 125 ?C in under 4 min.
Fatty Acid Methyl Ester (FAME) Composition in Fish Oil by Capillary GC
September 1st 2012The health benefits of fish oil in one's diet has been widely established. Common edible fish sources include salmon, trout, tuna, swordfish, and others. The omega-3 fatty acids, EPA and DHA, in dietary supplements (capsules) are primarily derived from smaller oily fish, notably anchovy, horse mackerel, bunker, capelin, and sand eel.