Principles of Sample Preparation by Grinding or Comminution: Sample preparation is the process where a representative piece of material, chemical or substance is extracted from a larger amount, bulk or batch for subsequent analysis. Representative samples are selected to accurately reflect the larger group and represent the characteristics of the whole material. Ideally representative samples are homogeneous or similar in nature, but when that is not possible, the best attempts must be made to achieve samples which represent the majority of the characteristics of the larger grouping.
Nafion®-Powder for the Production of Fuel Cell Electrodes: The Freezer/Mill ® a cryogenic mill is useful where other grinding procedures fail. Flexible materials like synthetics and biological samples are embrittled at Liquid Nitrogen temperatures. The sample is hermetically sealed and cross contamination is impossible.
Molecular Effects of Pollution in Cetacean Samples Using the Cytochrome P450, CYP 1A1, 1A2, and 1B1 as Biomarkers: Ocean Alliance is dedicated to the conservation of whales and the ocean environment through research and education. Ocean Alliance recently completed a five-year research voyage around the world known as the Voyage of the Odyssey (2000 to 2005). The Voyage of the Odyssey was launched to address the need for a globally integrated dataset allowing a consistent analysis of exposure to, and potential effects of, persistent organochlorines and other pollutants in marine life.
Structural Changes in Polymers by Means of Cryogenic Grinding: One goal in materials research is to develop new synthetic materials with characteristics that cannot be accomplished by the usual smelting process, as the polymers tend to separate during the heating process. Pure Polymer Trials to introduce permanent changes in polymers by means of Cryogenic Mechanical Milling (CMM) with the Freezer/Mill® were started with two polymers; isotactic polypropylene (iPP) and syndiotactic polystyrol (sPS).
The use of Cryogenic grinding to comply with the RoHS/WEEE Directive:The Restriction of Hazardous Substances (RoHS) and Waste Electrical and Electronic Equipment (WEEE) Directives of the European Union were introduced to minimize the accumulation of hazardous waste in landfills from the disposal of electrical and electronic equipment. The concentrations of hazardous substances such as lead, cadmium, mercury, chromium VI, polybrominated diphenylethers (PBDEs), and polybrominated biphenyls (PBBs) are restricted in electrical and electronic products and/or components. RoHS/WEEE states that if the component can be mechanically separated, then each component is subject to the RoHS limits.
Grinding Bone in the Freezer/Mill:Any plant or animal tissue can be ground in a SPEX Freezer/Mill, and this includes all bone: fresh or aged, wet or dry. Freezer/Mill grinding vials are immersed in liquid nitrogen (LN) before and during grinding, first to make the sample brittle enough to grind, and then to keep it brittle during the actual grinding. The actual grinding is done by a rod-shaped steel impactor that is magnetically shuttled back and forth between two steel end plugs.
RNA Extraction from Cartilage Tissue Using Cryogenic Grinding:The object of the study was to determine if there is a connection between the seriousness of arthritic diseases, especially of the knee joint and certain genes. To this end the expression profile of various genes in the tissue of healthy and diseased probands was compared. Total RNA was isolated from cartilage tissue and the activity of certain genes was analyzed via PCR or micro array analysis.
Preparation of Domestic Waste for Elemental Analysis: With kind permission of IBU-tec GmbH & Co. KG Domestic waste presents a very inhomogeneous mix made up of very different substances. Apart from polymer synthetics and organic substances like cork, wood, and paper there may be inorganic materials and metals present.
Grinding Polymers for Qualitative and Quantitative Analysis: In the application discussed here, the 6775 Freezer/Mill® was used for grinding compact synthetic (pellets, webbing fabric, textiles, etc. ) as well as polymer yarns, fleece material, filaments (polypropylene (PP), polyethylene or polyester).