Term
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Definition
| m (slope of calibration curve) |
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Term
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Definition
| m/sigma (slope/standard deviation): depends on the error made when measuring at specific concentrations. |
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Term
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Definition
| Limit of detection: 3sigma/m . |
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Term
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Definition
| Photoejection of an electron from the surface of a metal. |
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Term
| Ground State of a molecule |
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Definition
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Term
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Definition
| Promotion of an electron from ground state to excited electron state |
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Term
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Definition
| Band of emission from a hot, glowing object |
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Term
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Definition
Emission of light from excited state. Spin of electron does not change from original spin in ground state.
Light emission from singlet state |
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Term
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Definition
Emission of light from excited state. Spin HAS flipped from spin on ground state.
Light emission from triplet state |
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Term
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Definition
| N(d)=sin(i)/sin(r) where i and r are degrees of incidence and refraction respectively |
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Term
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Definition
| Current out of a phototube or photodiode in absence of light |
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Term
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Definition
| sensor whose output is proportional to size of some physical stimuli |
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Term
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Definition
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Term
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Definition
| in reversed biased semiconductor zone where electrons and holes have left because they have migrated towards the electrodes. |
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Term
Emission spectrum vs. excitation spectrum
Which resembles absorption spectrum? |
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Definition
Emission= excitation held constant, scans emission
Excitation-=emission held constant, scans excitation.
excitation like absorbance, excitation scanned |
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Term
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Definition
| wavelength of emission =wavelength of absorption |
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Term
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Definition
| Spins same in excited and ground states |
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Term
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Definition
| Spin flips in excited state |
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Term
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Definition
| going from high to lower vibrational levels without emitting light |
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Term
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Definition
| Radiationless relaxation (mostly from vibrational levels with similar energies) |
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Term
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Definition
| switching between singlet and triplet states |
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Term
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Definition
| ratio of # of molecules in specific energy level to total number of excited molecules |
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Term
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Definition
| cation binds to interferant, releases analyte for analysis |
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Term
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Definition
| like EDTA,complexes out analyte but is volatile enough to be driven off in flame |
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Term
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Definition
| High concentrations of electrons to prevent ionization of analyte |
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Term
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Definition
| vaporization and decomposition of sample into individual atoms |
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Term
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Definition
| High concentrations of atoms in flame cause broadening because of collisions |
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Term
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Definition
| made of same material as analyte, sputters off electrons when the inert gas cations hits the glass tubing |
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Term
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Definition
| overlapping spectral lines |
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Term
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Definition
| releasing and protecting agents |
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Term
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Definition
| atoms moving towards or away from detector are detected with different frequencies resulting in line width broadening |
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Term
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Definition
| unquantized energy level that lies between quantized levels where scattering occurs |
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Term
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Definition
| Property of molecule that has magnetic properties that vary with orientation |
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Term
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Definition
The measure of degree oto which circulation of electron around nucleus either reduce or increase the magnetic field felt by nucleus
sigma=(Bapplied-Bo)/Bo |
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Term
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Definition
| measures shift in ppm of peak of given nucleus from that of a reference (usually TMS) |
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Term
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Definition
| measuring amplitude of NMR signal as radio frequency is varied or field strength of magnet is scanned |
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Term
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Definition
| frequency of precession of a nucleus in an external field |
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Term
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Definition
| spacing in frequency units between peaks produced by spin-spin splitting |
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Term
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Definition
| chemical shift between interacting groups is large with respect to their coupling constant |
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Term
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Definition
process in which species are washed through a chromatographic column
by the flow or addition of fresh solvent |
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Term
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Definition
moves over or through an
immobilized phase that is fixed in place in a column or on the surface of a flat plate |
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Term
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Definition
solid or liquid that is fixed in
place. |
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Term
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Definition
e ratio of the concentration
(strictly acitivity) of the analyte in the stationary phase to its concentration (activity) in
the mobile phase when equilibrium exists between the two phases. |
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Term
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Definition
time interval between its injection onto a
column and the appearance of its peak at the other end of the column |
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Term
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Definition
source of band broadening in a column in which a solute
diffuses from the concentrated center of the band to the more dilute regions on either
side. |
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Term
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Definition
molecules of an analyte reach the end of a
column at different times as a result of traveling through the column by pathways that
differ in length. |
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Term
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Definition
fresh mobile phase that carries the analyte
through the column. |
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Term
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Definition
(1) large particle diameters for
stationary phases;
(2) large column diamters;
(3) high temperatures (important only in GC)
(4) for liquid stationary phases, thick layers of the immobilized liquid;
(5) very
high or very low flow rates. |
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Term
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Definition
method of performing liquid chromatography in which the
composition of the mobile phase is change continuously or in steps in order to optimize
separations. |
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Term
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Definition
solvent composition is held constant throughout the
elution |
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Term
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Definition
two or more solvents are used and the composition of the
mobile phase is changed continuously or in steps as the separation proceeds. |
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Term
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Definition
nonpolar packing that is used in partition
chromatography with a relatively polar mobile phase. |
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Term
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Definition
stationary phase is polar and the mobile phase is
relatively nonpolar. |
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Term
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Definition
process for removing dissolved gases from a solution by sweeping the
liquid with a stream of fine bubbles of an inert gas of low solubility. |
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