02 July 2009
By:Susanne Böhme, Hans-Ulrich Baier
This article reports on multidimensional gas chromatography using a multi-Deans switch that allows easy heart-cutting.
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02 July 2009
The new ultrafleXtreme exceeds any current expectations on MALDI-TOF-TOF technology: A proprietary kHz smartbeam-II MALDI laser integrated with a novel FlashDetector and electronics makes it the only MALDI-TOF-TOF on the market to provide kHz acquisition in MS and MS–MS modes. It generates a new level of data quality in applications such as LC-MALDI proteomics, high resolution tissue imaging based biomarker discovery or top-down sequencing.
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02 July 2009
Tobacco specific nitrosamines (TSNA) are a group of carcinogens found only in tobacco products and are formed from nicotine and related alkaloids during the production and processing of tobacco and tobacco products.
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02 July 2009
By:Jacquelyn Cole, Rui Chen
In many applications when comparing HPLC and SFC, one finds that SFC offers better selectivity and shorter analysis time as a result of the low viscosity and high diffusivity of supercritical fluids.
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02 March 2009
Conventional media for sample adsorption and extraction, stir bar sorptive extraction (SBSE) and solid-phase microextraction (SPME) are used in the form of a stirring bar or a fibre stick coated with an extracting polymer phase, for example, polydimethylsiloxane (PDMS). Disadvantages of conventional media are their small surface area and thin polymer phase coating resulting in low recovery and low sensitivity and the need for a long extraction time.
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02 December 2008
By:Claudia Niemann
Amylose is an occasionally-branched biopolymer and, together with amylopectin, the hyper-branched component, a constituent of starch. Determination of branching in amylopectin on the basis of amyloses may be performed with the help of synthetic amyloses. Synthetic amyloses from enzymatic (phosphorolytic) reaction were checked for their linearity.
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02 December 2008
By:Greg Saunders
In contrast with random copolymers where two or more monomers are included in a polymer chain in a statistically random manner, block copolymers contain isolated blocks of what are essentially homopolymers linked at one or more terminal positions. This regulated structure produces materials with novel properties not observed in random copolymer analogues, typically associated with phase behaviour at interfaces. Such copolymers have been exploited for their surfactant characteristics and for their propensity to form isolated domains in thin films. The simplest block copolymers are AB diblocks consisting of two chains of different polymers (A and B) joined at one terminal. Triblock polymers contain three separate polymer chains connected in series, typically composed of two (ABA triblocks) or three (ABC) different types of polymer chain. Producing block copolymers with blocks with widely differing chemistries results in materials with very unusual properties.
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02 December 2008
By:Dirk Krumwiede
This application details a fast, reliable and highly selective trace-level screening method for the quantification of polychlorinated biphenyls (PCBs) in environmental, food and biological samples, using gas chromatography and a triple stage quadrupole mass spectrometer. The analytical strategy is analogous to the well-established US Environmental Protection Agency (USEPA) Method 1668A.
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02 December 2008
By:Carsten Baessmann
An ultrafast gradient LC separation method was developed to separate a 5-component drug mixture in 30 seconds, with peak widths of 1 second. maXis mass accuracy at sub-ppm levels and true isotopic pattern of the spectra from the peaks lead to a confident elemental formula assignment for each drug compound with the SmartFormula algorithm.
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