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The Application Notebook-02-01-2012

The Application Notebook

Establishing USP Rebaudioside A and Stevioside Reference Standards for the Food Chemicals Codex

February 01, 2012

Articles

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The United States Pharmacopeial Convention (USP) publishes the Food Chemicals Codex (FCC), which is a compendium of food ingredient documentary standards (monographs) that provide tests, procedures, and acceptance criteria to indicate the safety and quality of a food ingredient. Physical reference standards can be associated with the procedures of an FCC monograph and the reference standards are needed for conducting the procedures. This article describes characterization and collaborative testing of new USP rebaudioside A and stevioside reference standards and their suitability for intended uses in the FCC rebaudioside A monograph.

Faster, More Sensitive Determination of Carbamates in Drinking Water

February 01, 2012

Food and Beverage

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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.

Analysis of Over 15 Million Dalton Polymers by Aqueous SEC Method

February 01, 2012

Polymer

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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.

LC–MS-MS Method for the Determination of Enalapril and Enalaprilat fro Human Plasma Using SOLA

February 01, 2012

Pharmaceutical

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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.

Microwave Assisted Extraction of Dioxins and Furans Compared to Soxhlet

February 01, 2012

Environmental

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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.

Fast Cap IC Determinations of Inorganic Anions and Cations in Drinking Water

February 01, 2012

Environmental

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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.

Screening for Pyrethroid Insecticides in Sediment Samples by GC–MS-MS

February 01, 2012

Environmental

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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.

Quantitation of Omega Fatty Acids by HPLC and Charged Aerosol Detection

February 01, 2012

Food and Beverage

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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.

Analysis of Multiple Classes of Cigarette Smoke Constituents by GCxGC-TOFMS

February 01, 2012

General

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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.

One-Step Extractio and Concentration for Identifying Pharmaceuticals and Personal Care Products in Water, Biosolids, and Solids

February 01, 2012

Environmental

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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.

Rapid On-Site Screening of Environmental VOCs in Soil using Solid Phase Microextractio and a person-Portable GC–MS

February 01, 2012

Environmental

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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.

Trace Metabolic Profiling and Pathway Analysis of Clomazone Using LC–MS-MS and High Resolution MS

February 01, 2012

Articles

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Detection, analysis, and characterization of low-abundant metabolites remain an unresolved problem in metabolic studies. In this study, we report a novel approach to address this challenge. The current methodology is derived from the predictive multiple reaction monitoring (pMRM) mode available on triple-quadrupole linear ion trap mass spectrometry (MS) systems. The pMRM mode offers the highest sensitivity among various acquisition modes for studying trace levels of metabolites of the herbicide clomazone in plants. Additionally, this method allows for the identification of positional isomers of metabolites.

Agarose-Heated Transfer Lines

February 01, 2012

Biological

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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 Column Protection Dramatically Extends UHPLC Column Performance and Lifetime

February 01, 2012

General

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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.

New HPLC/UHPLC Assay Methods for Impurities in Tetracycline

February 01, 2012

Pharmaceutical

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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.

HPLC Method for the Separation of Nine Key Components of Milk Thistle

February 01, 2012

General

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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.

Determination of Dyes in Fish Tissue by HPLC/UV

February 01, 2012

Food and Beverage

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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.

Impurities in Wines by GC–MS

February 01, 2012

Food and Beverage

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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.

Resistive Glass Inlet Tubes Increase Ion Throughput

February 01, 2012

General

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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.

Vol 30 No 2 LCGC North America February 2012 Application Notebook PDF

February 01, 2012

Issue PDF

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Click the title above to open the LCGC North America February 2012 Application Notebook, Vol 30 No s2, in an interactive PDF format.