CHROMATOGRAPHY, MASS SPECTROPHOTOMETRY AND LUMINESCENCE Flashcards
is an analytical technique commonly used for
separating a mixture of chemical substances into its
individual components, so that the individual
components can be thoroughly analyzed
Chromatography
→ could be Gas or liquid
→ Solvent moving through the column
→ Carries the sample
Mobile phase or carrier
→ Solid or liquid
→ Where the mobile phase flows
→ it does not move and stay fixed inside the column
Stationary phase or adsorbent
→ holds the stationary phase
→ it is where the sample moves
Column
→ separated components
● Eluate
→ the process of washing out a compound through a
column using a suitable solvent
● Elution
→ Mixture whose individual components have to be
separated and analyzed.
● Analyte
The time it takes for a compound or analyte to elute
Retention time or factor
● Chromatographic techniques may be classified
according to their mobile phase:
→ Gas Chromatography
→ Liquid Chromatography
separating compounds based primarily on their
volatility.
Gas Chromatography
easily evaporated at normal temperatures
● is useful for compounds that are naturally volatile or
can be easily converted into a volatile form
● Volatility
based on partition
Gas-Liquid Chromatography:
based on adsorption
Gas-Solid Chromatography:
is the emission of light by a substance
Luminescence
Give me the three types of luminescence
Fluorescence
Phosphorescence
Chemiluniscence
a beam of light is incident on certain substances, they emit visible light or radiation
fluorescence
atom or molecule that fluoresces
fluorophore
quick disappearance of fluorescence
quenching
give me the 5 basic components of fluorometry
light source
excitation
cuvette
emission
photodetector
delayed fluorescence
phosophorescence
when light radiation is incident on a certain substances they emit light continuously even after the incident light is cut off
phosphorescence
transition form a singlet to triplet state
intersystem crossing
opposite spin direction
Single state
same spin direction
triplet state
is a production of light from a chemical reaction
chemiluminescence
→ Packed columns or capillary columns
columns
very packed beads column, porous layer or
conventional inside the hollow portion of the
column.
It can be used on Gas-liquid and Gas-Solid
Chromatography
packed columns
coating (the red and blue) on the side of the
column, no particles have been added.
▪ Can only be used when using Gas-liquid
chromatography.
capillary or open column
two types of detector
thermal conductivity detector
Flame ionization detector
contain wires (filaments) that change electrical
resistance with change in temperature.
Thermal Conductivity detector
measures the unknown resistance values on
TCD.
▪ used for calibration on different instruments.
wheatstone bridge
carrier gas
helium
→ more sensitive than TC detectors.
→ uses small hydrogen flame (needed) and needs to
have a collector electrode.
Flame ionization detector
has mobile phase: (Carrier gas)
helium
argon
nitrogen
HAN
to measure analyte in a gas stream attached the
GC system
▪ universally employed where the flame is
commonly generated with hydrogen and air.
Flame Ionization Detector
introduce a sample into the inlets.
▪ manual insertion is possible.
Auto-Sampler
attached to the column head and provide the
means to introduce a sample into a continuous
flow of carrier gas
common inlet or injector
less interaction, travels faster and diluted
out first.
Components with less affinity of stationary
phase
more interaction, travels slower and diluted
later.
Components with more affinity to the stationary
phase
based on detention of ions formed during
combustion of organic compounds in a flame,
which is generated by hydrogen and air.
flame ionization detector
(where flame
produces)
Positive Electrode
(positioned
above the flame)
(positioned
above the flame)