Levels of benzene, toluene, ethylbenzene, xylenes, and styrene (BTEXS) are a concern in olive oil. These compounds find their way into olive trees and hence into olives and olive oil mainly as a result of emissions from vehicles, bonfires, and paints into ambient air near orchards. This analysis uses a PerkinElmer? TurboMatrix? 110 Headspace (HS) sampler with a Clarus? SQ 8 gas chromatograph–mass spectrometer (GC–MS) to achieve detection limits below 5 ng/g and concentrations up to 100 ng/g.
Natural gas and other gaseous fuels contain varying amounts and types of sulfur compounds which can be corrosive to equipment and can inhibit or destroy gas processing catalysts. Small amounts of sulfur odorants are added to natural gas and liquefied petroleum gases (LPGs) for safety purposes. Accurate measurement of sulfur species ensures proper process operation and odorant levels for public safety.
Aniline is an organic compound widely used in the polymer, rubber, pharmaceutical, and dye industries. Aniline and its derivatives (e.g., nitroanilines) are suspected carcinogens and are highly toxic to aquatic life. Because these compounds are thermolabile and polar, the traditional analytical methods require a derivatization step prior to GC analysis.
Selectivity is the most powerful tool to optimize separations in HPLC. This parameter is changed by using different bonded phases or by changing the mobile phase. In this work, Poroshell 120 columns with highly efficient 2.7 ?m superficially porous particles and the Agilent 1260 Infinity Series LC Multi-Method Solution were used to quickly evaluate method development choices for the analysis of steroids.
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.
This application note will highlight the extraction of EPA Method 508.1 analytes from an aqueous matrix. It will use the SmartPrep Extractor and the DryVap Concentrator system to achieve excellent recoveries while maintaining minimal user-interface.
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.
Ion 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.
Thermo Scientific Application Note
Typical 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.
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.
Underground 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).
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.
Excipients 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.
Protein 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.
Biotherapeutic 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.
Insulin was the first recombinant pharmaceutical produced. Currently, one of the critical quality control attributes of therapeutic insulin in the US and European Pharmacopoeia (USP and EP) monograph is the level of covalent high molecular weight (HMW) insulin as determined by HPLC size-exclusion chromatography.
Malaria remains one of the world's most deadly diseases, killing a child under five years of age every 30 s. Our branch aims to produce and characterize recombinant protein vaccines for Phase I and II human trials.
Compounds such as ibuprofen, chlorpheniramine, and allantoin are important in the field of pharmaceuticals and cosmetics. The analysis of acidic and basic compounds is particularly important but it is sometimes difficult to analyze both acidic and basic compounds on a single standard C18 column. Imtakt's Scherzo SM-C18 and Scherzo SW-C18 HPLC columns can separate acidic ibuprofen and basic chlorpheniramine simultaneously.
This application note demonstrates the use of the Thermo Scientific Syncronis C18 1.7 ?m column for the determination of esomeprazole by UHPLC-UV.
This application note demonstrates the use of the Thermo Scientific Accucore RP-MS column for the determination of telmisartan by HPLC-UV.
Beta blockers can be abused in sports involving little physical activity, such as archery, to reduce cardiac contraction, heart rate, and coronary blood flow.
The migration to chromatographic methods utilizing smaller particle sizes has been well demonstrated to increase productivity through faster, more efficient separations.
Positron emission tomography (PET) is one of the most powerful noninvasive diagnostic tools for tracing organ functioning. Quality control of the short-lived radiopharmaceuticals is challenging, not at least because of the tough time limits, the radiation issue, and the near nanomole radiotracer quantities.
Thermo Scientific 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.
The purpose of this study is to determine how the Direct-to-GC vial concentrator tube and the DryVap ® Concentrator System can optimize the recoveries for both low and high boiling point semi-volatile compounds.
Liposomes are made of lipid bilayers and are often used in drug delivery by encapsulating the core with therapeutic drugs. During liposome research, formulation, manufacturing, and quality control, it is of great importance to monitor liposome size and encapsulation.
U.S. EPA Method 531.2 describes the determination of widely used carbamate pesticides in raw surface water using HPLC with fluorescence detection following postcolumn derivatization, which enhances method sensitivity and selectivity as compared to UV absorbance detection.
