CHEMISTRY : Chromatography

Sample Analysis INK-002:
- Digital Edge Permanent Marker -

SAMPLE INFORMATION

Source	Permanent Marker
Sample Description or Commercial Name	Digital Edge Permanent Marker
Sample Colour	Black
Solvents Tested	Methanol (50%) Ethanol (30%, 50%, 60%, 70%) Propanone (40%, 50%, 60%, 70%, 80%) Methanoic Acid (50%, 75%) Chloroform Chloroform/Kerosene mixture 1:1 Kerosene Formaldehyde Xylene DiMethylSulphOxide (50%, 80%) Propanone/Ammonia mixture (7:3) Propanone / Ethanol / Water mixture (1:1:2, 3:3:4)

RESULTS

LEGEND of Results: (See picture for diagrammatic representation)

1. O - Separated - sample components separated into distinct circular-oval zones well spaced apart.
2. B - Semi separated - sample components exhibits themselves as zones intersecting into each other.
3. U - No Separation - sample forms an elongated streak usually from origin.
4. T - No Separation - sample moves with solvent front forming a flat edge with level of solvent.
5. X - No Separation - sample undissolved and remains at the original point of application.


6. PA - Point of Application (Origin)
7. * - Further remarks and details below.

FURTHER NOTES:

* 50% Ethanol

This mixture separated the 3 main components of the ink into 3 zones, Violet at the top, followed by the light blue dye and finally a black dye (residue?) streaking away from the PA. This solvent was also good to demonstrate that the violet dye consists of 2 different but closely related dyes almost the same colour. In many runs, 2 dense loci were formed at the violet zone.

* 75% Methanoic Acid

This solvent separated very well the violet dyes from the light blue dye below where in other solvents there were found merging into each other.

* 50-70% Propanone

This solvent produced interesting results when applied at gradual concentrations of 50%, 60%. 70%, 80%. At 80% the 2 violet dyes were merged in almost a single zone (sometimes with 2 dense loci near each other. At 70% a 2 dense and distinct violet zones were formed close the the solvent front where the most dense was at the top and the less dense below it. Below the violet complex zone was the light blue dye zoning just beneath. Interestingly, in the 50% concentration, the dense violet zone exhibited itself below the other violet zone (somehow paler). In this run, one can also observe a yellowish zone, masked between the 2 violet centres as a light patch along the violet streak. A black dye is also assumed to be present due the formation of a black/grey streak from the point of application and many of it remaining fixed there.

* Chloroform

A very long streak of unseparated dyes from point of application was formed.

* Kerosene / Kerosene+Chloroform mixture

The Kerosene was tried as a trial solvent and eventually it did not dissolve the Violet / Skyblue component dyes of the sample. However it should be noted that a pale grey-yellow zone was formed well up from the point of application. Since chloroform is miscible with kerosene (and not with water), and kerosene did not dissolve the violet and Light Blue dyes, a mixture of these was tried out in an attempt to dilute the strong solvent properties of Chloroform. This formed a longer streak of unseparated dyes from point of application and carried the grey-yellow component as a faint but well distinct zone above the coloured streak.

* Ammonia/Propanone Mixture 7:3

This mixture was the most successful to separate the light blue dye from the violet dye complex where the zones were separated by few centimetres. In other solvents the violet and light blue zones are often intersecting over each other or touching, hence rarely well separated. Moreover, the violet zone consisted of an upper pure violet colour and a lower violet blue colour and this can be explained by the fact that one of the violet dyes turns bluish in alkaline conditions provided by the Ammonia.

* Ethanol/Propanone/Water Mixture

2 mixtures were tried out: Propanone:Ethanol:Water mixture 1:1:2 (25%:25%;50%) and 3:3:4 (30%:30%:40%). Both gave similar results the most remarkable being the separation of the 2 violet dyes by few centimetres apart, a result not well achieved in other solvents. The light blue dye was somehow merged with the lower violet dye zone and showed up at the bottom esp. in the 3:3:4 mixture

DISCUSSION

From the patterns obtained, it can be concluded that there are 2 principle organic dyes a violet dye and a light blue dye. The violet dye was demonstrated by some solvents to consist of 2 closely related violet dyes with similar Rf Values and hence moved together along the medium. Best solvent to separate these violet dyes were Propanone: Ethanol:Water 1:1:2 or 3:3:4, and to a less extent 50%-70% Propanone.

There is also a black dye which was quite insoluble in many solvents and remained as a black spot at the point of application, with the exception of the solvent DimethylSulfOXide which transported most of the sample along the Chromatography paper and 80%-100% propanone which formed a black smear from Point of application to halfway the strip leaving a faint black dye at point of application. This is given the in house nick name of Inorganic Black since it is quite unsoluble in a number of solvents and remains at the point of application.

From the Kerosene:Choloroform Mixture (1:1) a faint yellow/beige zone was observed above the pigmented components. There was a hint of this yellow component in 50%-70% propanone and 60% Ethanol. Being so faint, it is likely that its purpose is not a dye but an impurity or additive. For this reason it is not given any significant importance.

From the Rf values, it seems that at least one of the violet dyes is the same as the dye nick-named Fast Violet 01, while the light blue dye showed inconsistent RF results and not well separated from the mixture and therefore it cannot be told if it is the same as the nick-named Skyblue 01. The latter showed a low RF value (less than 0.4) while the one in this sample was generally higher and just below the violet dye. For the time being this is given the in-house nick name of Light Blue FVT 01 (FVT standing for Fast Violet Trailer since it is always present at the 'tail' of the violet zone which is assumed to be the Fast Violet dye isolated in sample INK01

From the intensities obtained, the mixture of the 3 principle dyes is roughly estimated to be Violet complex:Light Blue:Black residue as 4:1:4.

Discussion based on the following results

Propanone 50% - 70%	Ethanol 60%	Chloroform:Kerosene 1:1	Propanone:Ethanol:Water 1:1:2

CONCLUSION

Ink in Sample INK002 - "Digital Edge Permanent Marker" consists of five components of which one (pale yellow/beige colour) is not considered as a dye but an additive or impurity. The principle dyes observed by Paper Chromatography are:

1. A Violet complex dye made of 2 dyes of which one corresponds to FAST VIOLET 01 and the other is a closely related dye of similar colour and physical characteristics.
2. LIGHT BLUE FVT 1 (10% approx.)
3. INORGANIC BLACK 1 (50% approx.)

Note that the names given to the dyes above are not the actual scientific names but nick named for reference purposes in these documents. Further research will perhaps reveal their proper names, but it is difficult to identify the actual dyes in a home laboratory till specific RF values of these commercial dyes are not given.

Percentage quantities given are only by visual estimation of the separated dye zones on the chromatography paper.

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