Intro to Analysis, Spectroscopy, and Chromatography
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Kartei Details
Karten | 24 |
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Sprache | English |
Kategorie | Chemie |
Stufe | Universität |
Erstellt / Aktualisiert | 06.01.2016 / 24.06.2016 |
Lizenzierung | Keine Angabe |
Weblink |
https://card2brain.ch/box/intro_to_analysis_spectroscopy_and_chromatography
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Define: analyte (1p)
analyte(s): compound(s) of interest in an analytical procedure
Define "analytical chemistry" and the two common categories of it (3p)
Analytical chemistry: measurement of propertie of a substance or system such that information about the chemical make-up of that system is obtained
1. Qualitative analysis: analysis by physical properties without quantitative data (some or all of the constituents of the system in question are identified)
2. Quantitative analysis: the concentration (or mass) of some or all constituents in a system are measured and identified
What are some factors to method selection? (5p)
1. Elemental or molecular in form
2. Organic or inorganic
3. Volatile or non-volatile
4. Low, medium, or high molecular weight
5. Ionic or non-ionic
What are the two most important considerations for method selection? Define them. (2p)
1. Selectivity: ability of the method to discriminate between different atoms/ions/compounds
2. Sensitivity: magnitude of the change in signal that results from an incremental change in concentration
Definte: limit of detection (LOD) (1p)
Limit of detection (LOD): lowest comcentration of a compound that may be statistically differentiated from the background noise
What two ways can you increase sensitivity? (2p)
1. Improve equipment used
2. Reduce the background noise
What are "descriptors" and what is the minimum number of them necessary to make a clear judgement? (2p)
Descriptors: element or term, qualities, that ha s the function of describing or identifying someone or something in particular
At least 2, completely independent descriptors are required to recognize someone from a distance
What does it mean when a presumptive colour test indicates that the object is positive for a certain substance? (1p)
The object is presumed to be positive for the substance, and fails to be excluded from the evidence