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CHEMISTRY : Chromatography

Solvents: ETHANOL



PROJECT CODE: 04.01c
SECTION: CHROMATOGRAPHY
PROJECT TITLE: Solvents Characteristics : ETHANOL (C2H5OH)
RELEASE DATE: 01 Jan 99 - 03 Jan 99
LAST UPDATE: 2 Sep 2009
VERSION HISTORY: 1.0 - First release
1.32 - (01Jan, 03Jan, 10Jan, 30Jan, 07Feb)
1.4 - Revision of text and formatting. (2-Sep-2009)



INTRODUCTION

Here are the chromatography characteristics of various concentrations of Methanol as a solvent. Such parameters are the speed, solubility and separation of the two dyes from a standard ink. Concentrations tested: 30%, 40%, 50%, 60%, 70%, and 80% Ethanol.

Chromatography characteristics that are tested include the speed , solubility and separation of the two dyes from the refernce ink.

  1. Solubility and Separation score is out of 10 were 0 is the worst and 10 is excellent
  2. Flow Rate is the portion (expressed as percent) of solvent that had moved along the 12cm strip of chromatography paper. For example if the solvent moved 6cm from the origin, the flow rate is given as 50%

Table of Results using the solvent PROPANONE (Acetone) at various concentrations in Paper Chromatography
Solvent: Ethanol - CH3-CH2.OH
Concentration 80% 70% 60% 50% 40% 30%
Flow Rate: 20% in 10mins
40% in 29mins
60% in 60mins
80% in 1:45hrs 20% in 10mins
50% in 43mins
60% in 60mins
40% in 25mins
78% in 1:45hrs
90% in 2:15hrs
20% in 9mins
50% in 45mins
60% in 60mins
20% in 9mins
50% in 45mins
65% in 60mins
Solubility: 9/10
Excellent, dyes move with level of solvent
/10
Excellent, very faint spot was left
8/10
Very Good
8/10
Very Good, quite dense and dark
6/10
Quite Good
3/10
Very faint but visible
Separation of dyes: 0/10
No separation at all.
3/10
Did not seperated, one zone with huge overlapping.
7/10
Good, roundish zones seperated by about 1mm
7/10
Good, roundish zones but nearly touching
8/10
Very Good, two seperate slightl enlongated zones
5/10
Quite good, but remains as long streaks
Allocated Time: 50 - 60 mins 1¾ - 2 hours 2 - 3 hours 2 - 2½ hours 90 - 100 mins 90 - 100 mins
Score: 26% 54% 92% 88% 82% 20%
Concentration 80% 70% 60% 50% 40% 30%
Comments: Although its great solubility, there is no separation of the two colours. The dyes move with the edge of the solvent rising in the strip, followed by a traling tail of both colours. If left for long, the dyes rapidly move to the very top of the solvent, forming just a insignificant line at the edge. To avoid this a short time of about 1hour is proposed. The dense colours on teh strip, and the faint application point left behind, prooves the excellent solubility. However separation was n ot complete, with the impression that the 2 zones merge into each other forming a single enlongated thick zone with a violet tip at the top, a cyan tail at the bottom, and a mixture at the centre. Propably the cyan dye moved further near the violet dye with an increase in concentration, merging the two zones into one. Excellent results, same separation as with 50%, with a distance of about 2mm from the two seperate roundish zones. This could be improved if leaving for 3hrs or so. The zone colours are well formed and dense especially the Cyan one. Excellent results both in separation and ammount of dye seperated (solubility). Two seperate roundish zones were formed, seperated by just about 2mm. This space was shown to increase if left for about 3hrs. Both colours are well visible due to good solubility. Excellent separation with distinct enlongated zones seperated by about 8mm from each other. However the solubility is rather low, seperating a relatively low ammount from the ink drop. Said that, both colours are well visible. Good separation forming enlongated thin zones at a distance of about 10 mm from each other. However due to the low concentration of ethanol very little ink was dissolved resulting in faint separation zones, - the cyan one hardly visibly.

SUMMARY:

BEST Separation: 60% Ethanol - 120-140mins
For wider separation: 40% Ethanol - 90-100 mins
Artistic effect - flame shape with merging colours: 70% Ethanol - 120mins








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