Size exclusion chromatography (SEC) is a simple HPLC technique used for the molecular weight (MW) distribution analysis of polymers. Several manufacturers provide SEC columns with different base materials and various pore sizes to cover a wide range of polymer analysis.
Simultaneous HPLC analysis of neurotransmitters can be challenging due to the similarity of their structures.
A liquid chromatography tandem mass spectrometry method for enalapril and enalaprilat from human plasma has been developed using Thermo Scientific SOLA cartridges. Sample preparation is fast, efficient, and reproducible giving excellent recovery levels for each compound.
The paralytic shellfish toxins are a group of 18 secondary metabolites deposited in bivalve mollusks by dinoflagelates. Dinoflagelate blooms are seasonal, occurring during warm months.
Microwave assisted extraction (MAE) offers significant benefits over traditional soxhlet extraction for dioxins and furans determination from environmental samples including higher sample throughput, time savings, reduced solvent and great reproducibility.
The determination of common inorganic anions and cations in drinking water is important due to the toxicity of anions (e.g., fluoride, nitrite, and nitrate) and secondary contaminants (e.g., chloride and sulfate) which can affect the water's aesthetics.
A simple screening method for Pyrethroid insecticides in sediment samples is described. Electron impact ionization (EI) with tandem MS-MS in combination with programmed temperature vaporization injection (PTV) were used in order to obtain excellent specificity and low limits of detection.
Omega-3 and -6 fatty acids are essential compounds required for normal growth. Omega-3 consumption is purported to have a number of health benefits, e.g., cancer prevention, cardiovascular disease prevention, and improved immune function. Although both omega-3 and -6 fatty acids can give rise to eicosanoid-signaling molecules (prostaglandins, prostacyclins, thromboxanes, and leukotrienes), the omega-6 eicosanoids are generally proinflammatory. A person's diet requires a balance of omega fatty acids at suitable levels.
A new widepore core-shell HPLC–UHPLC column (aeris WIDEPORE) has been introduced that is specifically designed to improve protein separations.
GCxGC-TOFMS provided a comprehensive analysis of tobacco smoke. Individual smoke constituents across several target compound classes were extracted, chromatographically resolved, then identified and quantified with mass spectral detection.
Over the last decade the use of Pharmaceuticals and Personal Care Products (PPCPs) has doubled in the United States. As a result, PPCPs have entered the environment through both human activity and as by-products from manufacturing, agricultural activities, medical use and veterinarian facilities.
Volatile organic compounds (VOCs) in soil were rapidly extracted and concentrated using solid phase microextraction (SPME) followed by on-site analysis and identification with the TRIDION-9 portable gas chromatograph – toroidal ion trap mass spectrometer (GC-TMS). 37 VOCs were resolved and analyzed quickly in under 3 min.
Shale gas reservoirs, such as the Marcellus shale reserve in Pennsylvania and Barnett shale reserve in Texas are a growing source of natural gas in the United States.
Using a novel new-design monolithic silica column (Chromolith? HighResolution RP-18e), fast, high resolution separations were achieved for various drug mixtures without the high pressures characteristic of modern particulate technology.
The benefits of olive oil as part of a healthy diet reaches back to the 1950's. Methods were developed to determine benzene, toluene, ethylbenzene, xylenes and styrene (BTEXS) by static headspace methods.
Agarose is a polysaccharide produced from seaweed that forms a gel at room temperature. The characteristics of agarose gels depend on the agarose concentration, solvent, weight-average molar mass, and molar mass distribution.
UHPLC columns can significantly improve chromatographic separations, but they also present unique challenges. Once the UHPLC system components are optimized, perhaps your greatest concern is protecting the column from the damaging effects of microparticulates and sample contaminants.
Tetracycline (TC), a common antibiotic used to treat urinary tract infections, acne, gonorrhea, and other conditions, yields a toxic degradation product, 4-epianhydrotetracycline (EATC). General Chapter 226 of the U.S. Pharmacopeia and National Formulary (USP-NF), referred to by monographs for epitetracycline and drug products containing tetracycline hydrochloride (TC-HCl), prescribes an antiquated assay for EATC impurity in TC.
For the analysis of biotherapeutics, size-exclusion and ion-exchange chromatography are typically conducted under native separation conditions, requiring high ionic strength, 100% aqueous eluents.
Synthetic fused silica capillary tubing is used in the manufacture of most gas chromatography (GC) columns. In this note, we discuss recent advances in the dimensional control of the most popular tubing sizes.
Silymarin, derived from the milk thistle plant, has been used as a natural remedy for the treatment of a number of liver diseases as well as in the protection of the liver from potential toxins. More recently, silymarin has been connected to antitumor promoting activity (1). It is therefore of interest to have available analytical methods for the analysis of silymarin components in various matrices.
Various triarylmethane and fluorescent dyes are used in aquaculture as antibacterial, antifungal, and anthelmintic agents for the treatment of fish disease. The FDA has banned the importation of certain fish from several countries due to possible contamination of these food products.
By identifying maturation tracers and molecules commonly responsible for taste defects, gas chromatography–mass spectrometry (GC–MS) augments expert opinion with objective and quantitative information. When using a solid phase micro extraction (SPME) method, GC–MS requires very small sample sizes and a minimum of sample preparation while providing rapid analysis of target molecules. GC–MS can provide an automated technique with repeatable results for detecting all of these compounds.
Saccharides are fundamental substances that express various bioactivities and may exist independently or form complexes with proteins or lipids.
Blueberries are extracted into acidified methanol and analyzed for anthocyanins with a methanol/formic acid gradient via UHPLC/MS; four different Agilent ZORBAX RRHD stationary phases are quickly evaluated.
Resistive glass tubes and plates are designed to guide ions by generating a uniform electric field. PHOTONIS resistive glass products are composed of a proprietary lead silicate glass that has been specially processed to create a resistive layer at the surface. The resistivity can be varied over several orders of magnitude to suit the specific application.
Basic compounds often require basic additives in the modifier to improve peak shape and resolution in SFC (1). These additives can be difficult to remove post-purification (2).
Ultrahigh-performance TOF–MS is utilized for the identification of a common pharmaceutical compound's metabolites. Mass spectral analysis is combined with UHPLC and post-source fragment ion generation to facilitate analysis.
Diclofenac is a slightly acidic (pKa = 4.0) non-steroidal anti-inflammatory drug (NSAID) that has been used as a post operative pain reliever in adult and pediatric patients.
