App Notes

Hydrogen Generators that are utilised to provide Carrier Gas for GC and GC/MS applications employ many technologies to provide high purity hydrogen. Here were look at the various methods used to purify hydrogen. Three using PEM (Proton Exchange Membrane), combined with various purification techniques, and the fourth using a combined Palladium Electrolyser.

This Application Note shows the potential of NIRS as a rapid (< 30 s) and nondestructive screening tool for solid dosage forms (e.g., tablets). NIRS requires neither sample preparation nor solvent use. Interferences that derive from scattering are minimized by converting to second derivative spectra.

This application note describes a method of extraction for metanephrine and normetanephrine from synthetic urine using EVOLUTE EXPRESS CX 96 fixed well plates.

Size exclusion chromatography (SEC) is the standard method for aggregate and fragment analysis of monoclonal antibodies in biopharmaceutical QC. A new series of silica-based SEC columns was engineered to provide shorter analysis time or higher resolution than standard columns for the separation of fragments, monomers and dimers.

The selection of the correct autosampler vial type is vital to the success of analyzing pyrethroid pesticides at low levels. A method for the determination of pyrethroids at 0.10 ng/mL was developed using solid phase extraction (SPE) for pre-concentration with subsequent analysis by GC with PTV simulated on-column injection. Careful selection of the autosampler vial type was needed to minimize adsorption effects.

This application note compares the performance of the solid core Thermo Scientific Accucore XL C8 4 μm HPLC column with that of a fully porous 5 μm traditional HPLC column for the analysis of triazines under gradient mobile phase conditions.

Polychlorinated biphenyls (PCBs) are man-made organic compounds composed of two phenyl (benzene ring) groups with multiple chlorine atoms attached. The heat-resistant and non-conductive properties of PCBs led to their extensive use as coolants and lubricants in electrical equipment until the late 1970s when their toxicity was recognized and their usage restricted. However, PCBs are very persistent environmental contaminants. Improper disposal and storage of old electrical equipment continue to allow the chemicals to leach into the environment. Soil and water samples are routinely tested for the presence of PCBs, and a number of EPA methods exist for their analysis.1,2 This HPLC method shows the use of the Thermo Scientific Accucore C18 column for the separation of PCBs in a commercial mixture. The 20 minute analysis time provides good resolution between all components.

To develop an efficient high-performance liquid chromatography (HPLC) method for the simultaneous determination of 19 phthalate compounds in drinking water. The 19 target analytes cover those specified in European Union (EU) Directive 2005/84/EC;1 U.S. Environmental Protection Agency (EPA) Methods 606 and 8061A;2,3 the Chinese HJ/T 72-2001;4 and the Standardization Administration of China (SAC) GB/T 20388-20065 and GB/T 21911-2008.6

A method for the determination of pyrethroids in water at ultra-low-level concentrations of 0.02 and 0.10 ng/mL was developed using solid-phase extraction (SPE) for pre-concentration and subsequent analysis by GC with PTV injection. Careful selection of the autosampler vial type was needed to minimize adsorption effects.

The use of QuEChERS dispersive SPE as a simple, fast, and quantitative sample preparation method is demonstrated for the GC-MS analysis of 18 polycyclic aromatic hydrocarbons (PAHs) in soil. The suitability of the Thermo ScientificTM TraceGOLDTM TG-17SilMS GC column for the separation of 18 PAHs is also shown. The average recoveries for the spiked 18 PAHs in soil at 1 mg/kg were between 85.0% and 106.7% with relative standard deviations between 0.3% and 2.8% using the original QuEChERS methodology.