paper and thin-layer chromatography Flashcards
Stationary phase: Plate (paper or tlc) in PAPER CHROMATOGRAPHY
Water (adhering on the paper)
**liquid-polar
Stationary phase: Plate (paper or tlc) in THIN-LAYER CHROMATOGRAPHY
Silica (solid - polar)
Mobile Phase (Solvent System) in PAPER CHROMATOGRAPHY
ethanol: ammonium hydroxide
** liquid - polar
Mobile Phase (Solvent System) in THIN-LAYER CHROMATOGRAPHY
75% pet.ether: 25% acetone
** nonpolar
Means of visualization in PAPER CHROMATOGRAPHY
spray w/ Ninhydrin
Means of visualization in THIN-LAYER CHROMATOGRAPHY
UV Light
What type of chromatography is a paper chromatography
Ascending
What type of chromatography is a THIN-LAYER CHROMATOGRAPHY
Ascending
Compound separated in PAPER CHROMATOGRAPHY
Amino Acids
Compound separated in THIN-LAYER CHROMATOGRAPHY
Analgesics
Advantages in PAPER CHROMATOGRAPHY
-Cheap
-best for polar compounds
Advantages in THIN-LAYER CHROMATOGRAPHY
-Faster
-Develop more compact spots
what will happen if the applied spots are too large
the developed spots will overlap and also results to tailing
The portion of the paper which we happen to touch also develop violet spots. This means that sweat contains ________
amino acids
what happens if the solvent level is above the applied spots
the spotted compounds will dissolve in the solvent system
what will happen if the solvent is allowed to overrun the paper or TLC plate
we cannot compute the Rf value
In TLC, the solvent system, the mobile phase is _______. ________, the stationary phase is polar
nonpolar
The greater the Rf, _________
the more nonpolar the analgesic
Formula for the Retention factor (Rf)
Rf = distance travelled by substance/ distance travelled by solvent
what compound will elute first on the plate
compount with HIGHEST Rf value
The Higher Rf, the ________ the compound, thus ________
less polar
basic
relationship between Rf values and Polarity
inversely proportional
why is it necessary to maintain a saturated vapor atmosphere in the developing chamber?
to stop the solvent from evaporating as it rises uo the paper. too much solvent evaporated from the plate and components will not move as far
what can be done to improve the results in the experiment (paper and thin layer chromatography)
proper location and exact estimation of middle point must be done
the physical separation of the components of a mixture on the basis of their differing affinities for a stationary phase vs. a mobile phase.
Chromatography
In ________ chromatography, the mixture is spotted onto a sheet of paper
Paper
paper chromatography works because of
the capillary action of water/solvent in the paper
this allows us to separate compounds due to the attraction, or affinity, of the compounds for tge mobile phase vs the stationary phase
Capillary action
the relative distance of travel of the substance to that of the solvent
Retention factor (Rf)
It forms colored compounds with amino acids
Ninhydrin
why does changing the solvent system would result toba different Rf value
altering the solvent system can change the relative positions of the separated compounds, resulting in different Rf values.
the technique of separation and identification of chemical substance by a MOVING SOLVENT on a thin layer of suitable adsorbent with a binder serving as inert support for the layer
Thin-layer chromatography
