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Dionex Application Note

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.

EPA is updating method 525.2. The CCL3 includes 104 analytes. UCT has evaluated the recoveries of these compounds, including the current list, using proposed changes to the method with the C18-based UCT ENVIRO-CLEAN? 83 mL Extraction Cartridge ECUNI525.

PSS Application Note

Metrohm Application Note

Fast, flexible platforms for peptide quantification are needed, particularly for a discovery setting. This type of methodology would be especially advantageous in the case of amyloid beta (a?) peptides.

Benzylideneacetophenone forms the central core for a variety of important biological compounds, known collectively as chalcones. Many of these compounds have significant medicinal value as they demonstrate antibacterial, antifungal, antitumor, and anti-inflammatory properties.

Metabolomics, the study of small molecule metabolites that are found within a biological sample, is an emerging field of study. Progress in this field depends upon technological advancement in the fields of LC–MS and separation technology.

Gelatin is the denatured form of collagen, the main component of skin, bone, and connective tissues of animals. Its special properties are a sharp sol-gel transition, low sol viscosity, and high effectiveness as a protective colloid.

This study demonstrates a faster method of analysis when coupling a simplified and effective SPE procedure with a core-shell HPLC column and LC–MS-MS detection.

One of the biggest debates in clinical medicine currently revolves around understanding the proper levels of vitamin D in patients' plasma.

Dionex Application Note

A new, efficient, effective, and sensitive sample preparation application for the extraction of the catecholamines epinephrine, norepinephrine, and dopamine from human plasma at significantly low levels using EVOLUTE WCX, a resin-based mixed-mode sorbent with an optimized combination of nonpolar (hydrophobic) and weak cation exchange interactions.

Barbiturates are a class of antidepressants whose abuse and addiction by recreational users has become a widespread problem (www.nlm.nih.gov). In our work we strived to streamline the barbiturate screening process to provide a fast, cost-effective, and reproducible method from start to finish for forensic labs who are involved in high-throughput processing.

International regulations on maximum residue levels (MRLs) of pesticides in food cover hundreds of individual contaminants at the 10 ppb or below range. The analysis of citrus oil for pesticide contamination holds specific challenges.

Endothall is a widely used herbicide for both terrestrial and aquatic weeds. Exposure to endothall in excess of the maximum contamination level (MCL) can cause illness. Endothall is regulated by the U.S.

This application note describes the method for detection of nanogram levels of explosive constituents in seawater samples (e.g., after detonation of unexploded ordnance devices). The improved chromatographic method was developed using the Agilent 1290 Infinity LC Method Development system.

The chiral analysis and purification of proton pump inhibitors (PPIs) has become a popular topic as more of these drugs fall out of patent protection each year. Due to their wide range of enantiomeric selectivity, a set of polysaccharide-based chiral stationary phases (CSPs) was screened to identify methods for the successful enantioseparation of four benzimidazoles; rabeprazole, lansoprazole, omeprazole, and pantoprazole.

The chemicals 2- and 4-methylimidazole (2-MI and 4-MI) are by-products produced during the manufacturing of caramel coloring ingredients used to darken food products such as carbonated beverages and soy sauce.

Anthocyanins are a sub-class of naturally electron deficient and powerful antioxidants called flavonoids that are responsible for the red, orange, and blue coloration in fruits and flowers.

Tea, one of the most consumed non-alcoholic drinks worldwide, contains catechins that are powerful antioxidants thought to provide many health benefits, including reduction of cholesterol and obesity, and protection against cardiovascular disease and cancer.

PCBs are a group of synthetic organic chemicals that contain 209 individual compounds (known as congeners) with varying harmful effects. PCBs enter the environment as mixtures containing a variety of individual components.

High performance time-of-flight mass spectrometry (TOF-MS) is applied to the analysis and characterization of complex biological samples. High mass accuracy, high resolution, and accurate relative isotope abundance are all applied to the determination of analytes covering a range of concentrations in complex matrices including plasma and urine. Qualitative and quantitative evaluations are provided and include demonstrations of the impact of high-performance MS on sensitivity and selectivity. The ability to leverage high-performance MS in conjunction with a broad dynamic range in rapid ultrahigh-pressure liquid chromatography (UHPLC) analyses to identify unknowns and to propose putative metabolic biomarkers is demonstrated. The impact of speed of analysis and selectivity to the depth of coverage and accuracy of the analyses are discussed.

Waters Application Note

Glyphosate is a broad-spectrum herbicide widely used around the world. Monitoring of glyphosate in crops and water is mandated in many countries.

A new series on valves and the pivotal role they play in gas chromatography.

This study evaluates the performance of a C18 core-shell phase that incorporates a C18 ligand with iso-butyl side chains. The Kinetex? XB-C18 HPLC/ UHPLC column delivers a fast and effective separation of several common preservatives in cosmetics.

Due to the increasing number of toxic pesticides being used throughout the world, a robust method for positively identifying low levels of multiple classes of pesticides is required. A Zebron? ZB-MultiResidue? column is used with GC–MS to identify over 100 common pesticides.

Dionex Application Note

Testosterone was extracted from human serum by strong anion exchange polymeric SPE and analyzed using a Kinetex C18, 30 ? 2.1 mm, 1.7 ?m column and positive polarity ESI LC–MS-MS system. Kinetex sub-2 ?m core-shell technology offers higher efficiencies than traditional sub-2 ?m columns, producing greater chromatographic resolution, sensitivity, and higher peak capacities.