Search Results

Accelerator mass spectrometry original

notation	A-MS
broader	Mass spectrometry original
definition	In this technique, the target element is first chemically separated from the sample before it is placed in a sample holder in the AMS instrument. The sample element is then bombarded by cesium ions to sputter the analyte element from the sample as negative ions. The analyte ions are then accelerated down a beam tube by a positive potential difference of several million volts, passed through an electron stripper to convert them to positive ions, and accelerated back down the beam tube toward common potential where ion velocities approach a few percent of the speed of light. Using a series of magnetic and electrostatic mass filters, the ion beam containing all isotopes of the analyte element is then separated into separate beams containing the (usually unstable) isotope of interest and other isotopes, and each of the isotopes is counted by a separate detector. (Skoog, Holler & Crouch, p. 271). Components: 1) sample preparation: chemical concentration of analyte; 2) ionization: ion beam; 3) mass analyzer: accelerator Mass spectrometer; 4) detector: not specified.

Mass spectrometry original

notation	MS
broader	Particle spectrometry original
definition	Study of matter through the formation of gas-phase ions that are characterized using mass spectrometers by their mass, charge, structure, and/or physico-chemical properties. (Source: IUPAC; https://doi.org/10.1351/PAC-REC-06-04-06). Atomic mass spectrometric analysis involves: (1) atomization, (2) conversion of a substantial fraction of the atoms formed in step 1 to a stream of ions (usually singly charged positive ions), (3) separating the ions formed in step 2 on the basis of their mass-to-charge ratio (m/z), where m is the mass number of the ion and z is the number of fundamental charges that it bears, and (4) counting the number of ions of each type or measuring the ion current produced when the ions formed from the sample strike a suitable transducer. (Skoog, Holler & Crouch, p. 253). Molecular mass spectrometry is used to determine the structures of inorganic, organic, and biological molecules and the qualitative and quantitative composition of complex mixtures; The appearance of mass spectra for a given molecular species strongly depends on the method used for ion formation. That these methods fall into three major categories: gas-phase sources, desorption sources, and ambient desorption sources. (Skoog, Holler & Crouch, p. 502)

Acid reaction carbonate analysis original

notation	ARCA
broader	Wet chemistry original
definition	Determination of calcium carbonate content by reaction with an acid and determining the quantity of CO2 produced. Different techniques use different acids and CO2 production measurement approaches.

Wet chemistry original

notation	WET
broader	Bench chemistry original
definition	Wet chemistry is a form of analytical chemistry that uses classical methods such as observation to analyze materials. It is called wet chemistry since most analyzing is done in the liquid phase. (https://en.wikipedia.org/wiki/Wet_chemistry)

Adsorption analysis original

notation	ADS
broader	Physical property measurement original
definition	The gas adsorption technique may used to measure the specific surface area and pore size distribution of powdered or solid materials. The dry sample is usually evacuated of all gas and cooled to a temperature of 77K, the temperature of liquid nitrogen. At this temperature inert gases such as nitrogen, argon and krypton will physically adsorb on the surface of the sample. This adsorption process can be considered to be a reversible condensation or layering of molecules on the sample surface during which heat is evolved. Nitrogen gas is ideal for measuring surface area and pore size distribution. (http://www.cyto.purdue.edu/cdroms/cyto2/6/coulter/ss000107.htm)

Physical property measurement original

broader	Analytical method original
definition	Various techniques used to measure the physical properties of a sample.

AFM topography imaging original

notation	AFMT
broader	Atomic force microscopy original Imaging techniques original Surface analysis original
definition	a sharp probe tip mounted on a microcantilever scans over the specimen line by line, whereby the topographic image of the sample surface is generated by 'feeling' rather than 'looking.' (https://doi.org/10.1007/978-3-642-16712-6_496). As the tip approaches the surface, the close-range, attractive forces between the surface and the tip causes the cantilever to deflect towards the surface. However, as the cantilever is brought even closer to the surface, until the tip makes contact with it, increasingly repulsive forces takes over and causes the cantilever to deflect away from the surface. (https://lnf-wiki.eecs.umich.edu/wiki/Atomic_force_microscopy)

Atomic force microscopy original

notation	AFM
broader	Physical property measurement original
definition	a high-resolution, non-optical imaging technique that uses a cantilever with a sharp tip to scan over a sample surface. AFM can be used to image almost any type of surface, including polymers, ceramics, composites, glass, and biological samples. AFM can also be used to measure and localize many different forces, including adhesion strength, magnetic forces, and mechanical properties.

Imaging techniques original

broader	Analytical method original
definition	Methods that produce 2-D or 3-D rasters that contain information about a sample, with data points that are spatially related to points on in the sample.

Surface analysis original

notation	SA
broader	Analytical method original
definition	Analytical techniques focused on characterizing the surface of a sample.