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The application of triphenylmethane dyes to visualization of selected aliphatic compounds in thin-layer chromatography
MICROCHEMICAL
JOURNAL
24, 298-299
(1979)
The Application of Triphenylmethane Dyes to Visualization of Selected Aliphatic Compounds in Thin-Layer Chromatography ZBIGNIEW Department
KWAPNIEWSKI*
AND
ROMUALD
of Analytical Chemistry, Technical Cracow, Poland Received
November
CICHO~ University.
8, 1978
INTRODUCTION
The problem of visualizing organic substances on a thin layer is of serious importance from the analytical point of view. From the wider range of triphenylmethane dyes, there are only fuchsine dyes, which have found certain application as visualizing agents (2). The aim of this work is to investigate the possibilities to apply new fuchsine, malachite green, and methyl violet as visualizing agents with selected aliphatic compounds tested by means of thin-layer chromatography . EXPERIMENTAL
Kieselgel GF,,, (E. Merek, West Germany), layer thickness of 0.3 mm, was used as an adsorbent, the activation period at 110°C lasting 30 min. The mobile phase was composed of chloroform and acetone at a volume ratio of 8:2. On the adsorbent layer, changing microgram amounts of the examined substances were placed, preserving in each case the same volume of the applied solutions. After developing and drying at room temperature for 24 hr, the glass plates were visualized by spraying with the visualizing agents. On 100 cm2 of a glass plate, 5 ml of the 0.01 N water solutions of the examined triphenylmethane dyes was used. With the investigated acids, the obtained Rf values were 0.33, with the alcohols, 0.62, and with the amines, 0.30. RESULTS AND DISCUSSION
From the results obtained (Tables 1 and 2), the triphenylmethylene dyes are the most efficient visualizing agents with fatty acids, fatty alcohols, and aliphatic amines. New fuchsine, malachite green, and methyl violet all demonstrate the following order of diminishing efficiency with the applied groups of substances: acids -amines -alcohols. Also, the contrast indexes, which were determined by means of the already described * Deceased. 298 0026-265X/79/030298-02$01.00/0 Copyright @ 1979 by Academic Press. Inc. All rights of reproduction in any form reserved.
DYES
IN
THIN-LAYER
299
CHROMATOGRAPHY
TABLE
1
DETECTABILITY (IN MICROGRAMS)OF HIGHER ALIPHATIC COMPOUNDS,VISUALIZED ON THIN LAYERS BY MEANS OF TRIPHENYLMETHANE DYES Micrograms Compound
Number of carbon atoms per molecule
New fuchsine
Malachite green
Methyl violet
Laurie acid Palmitic acid Arachidic acid
12 16 20
0.20 0.44 0.88
0.20 0.44 0.88
0.20 0.44 0.88
Lauryl alcohol Cetyl alcohol Arachidyl alcohol
12 16 20
4.4 4.4 2.2
4.4 4.4 2.2
4.4 4.4 2.2
Dodecylamine Hexadecylamine Eicosanamine
12 16 20
0.44 0.44 2.2
0.44 0.44 2.2
0.44 0.44 2.2
AND METHYL
VIOLET
TABLE THE CONTRAST
INDEXES
OF
NEW FUCHSINE,
2 MALACHITE
GREEN,
Contrast index New fuchsine Compound Palmitic acid Cetyl alcohol Hexadecylamine
a (“)
h (cm)
30 89 29
0.4 0.6
1.1
Malachite green ff (7
h (cm)
30 87 28
0.4 0.6
1.0
Methyl violet fl (7
h (cm)
29 80 27
1.2 0.4 0.7
method (Z), support the aforementioned statement, concerning the best visualizing effect with acids, then with amines, and finally, with alcohols. The differences observed with visualizing and the contrast index values are at least partially due to the dissolving effect of the examined substances during developing and spraying of the chromatograms, as well as to the different adsorption power of the applied dyes on the chromatographically analyzed substances. All of the discussed dyes belong to the group of the preserving visualizing agents. SUMMARY Selected triphenylmethane dyes were used as new visualizing agents in thin-layer chromatography of higher fatty acids, higher fatty alcohols, and higher aliphatic amines.
REFERENCES 1. Gregorowicz, Zb., and Sliwiok, J., Indexes for estimation of developing reagents in thin-layer chromatography. Microchem. J. 15, 60-63 (1970). 2. Sliwiok, J., On the mechanism of detectmg selected organic substances by means of fuchsine dyes and the method of thin-layer chromatography. Microchem. J. 14, 376-379
(1969).
JOURNAL
24, 298-299
(1979)
The Application of Triphenylmethane Dyes to Visualization of Selected Aliphatic Compounds in Thin-Layer Chromatography ZBIGNIEW Department
KWAPNIEWSKI*
AND
ROMUALD
of Analytical Chemistry, Technical Cracow, Poland Received
November
CICHO~ University.
8, 1978
INTRODUCTION
The problem of visualizing organic substances on a thin layer is of serious importance from the analytical point of view. From the wider range of triphenylmethane dyes, there are only fuchsine dyes, which have found certain application as visualizing agents (2). The aim of this work is to investigate the possibilities to apply new fuchsine, malachite green, and methyl violet as visualizing agents with selected aliphatic compounds tested by means of thin-layer chromatography . EXPERIMENTAL
Kieselgel GF,,, (E. Merek, West Germany), layer thickness of 0.3 mm, was used as an adsorbent, the activation period at 110°C lasting 30 min. The mobile phase was composed of chloroform and acetone at a volume ratio of 8:2. On the adsorbent layer, changing microgram amounts of the examined substances were placed, preserving in each case the same volume of the applied solutions. After developing and drying at room temperature for 24 hr, the glass plates were visualized by spraying with the visualizing agents. On 100 cm2 of a glass plate, 5 ml of the 0.01 N water solutions of the examined triphenylmethane dyes was used. With the investigated acids, the obtained Rf values were 0.33, with the alcohols, 0.62, and with the amines, 0.30. RESULTS AND DISCUSSION
From the results obtained (Tables 1 and 2), the triphenylmethylene dyes are the most efficient visualizing agents with fatty acids, fatty alcohols, and aliphatic amines. New fuchsine, malachite green, and methyl violet all demonstrate the following order of diminishing efficiency with the applied groups of substances: acids -amines -alcohols. Also, the contrast indexes, which were determined by means of the already described * Deceased. 298 0026-265X/79/030298-02$01.00/0 Copyright @ 1979 by Academic Press. Inc. All rights of reproduction in any form reserved.
DYES
IN
THIN-LAYER
299
CHROMATOGRAPHY
TABLE
1
DETECTABILITY (IN MICROGRAMS)OF HIGHER ALIPHATIC COMPOUNDS,VISUALIZED ON THIN LAYERS BY MEANS OF TRIPHENYLMETHANE DYES Micrograms Compound
Number of carbon atoms per molecule
New fuchsine
Malachite green
Methyl violet
Laurie acid Palmitic acid Arachidic acid
12 16 20
0.20 0.44 0.88
0.20 0.44 0.88
0.20 0.44 0.88
Lauryl alcohol Cetyl alcohol Arachidyl alcohol
12 16 20
4.4 4.4 2.2
4.4 4.4 2.2
4.4 4.4 2.2
Dodecylamine Hexadecylamine Eicosanamine
12 16 20
0.44 0.44 2.2
0.44 0.44 2.2
0.44 0.44 2.2
AND METHYL
VIOLET
TABLE THE CONTRAST
INDEXES
OF
NEW FUCHSINE,
2 MALACHITE
GREEN,
Contrast index New fuchsine Compound Palmitic acid Cetyl alcohol Hexadecylamine
a (“)
h (cm)
30 89 29
0.4 0.6
1.1
Malachite green ff (7
h (cm)
30 87 28
0.4 0.6
1.0
Methyl violet fl (7
h (cm)
29 80 27
1.2 0.4 0.7
method (Z), support the aforementioned statement, concerning the best visualizing effect with acids, then with amines, and finally, with alcohols. The differences observed with visualizing and the contrast index values are at least partially due to the dissolving effect of the examined substances during developing and spraying of the chromatograms, as well as to the different adsorption power of the applied dyes on the chromatographically analyzed substances. All of the discussed dyes belong to the group of the preserving visualizing agents. SUMMARY Selected triphenylmethane dyes were used as new visualizing agents in thin-layer chromatography of higher fatty acids, higher fatty alcohols, and higher aliphatic amines.
REFERENCES 1. Gregorowicz, Zb., and Sliwiok, J., Indexes for estimation of developing reagents in thin-layer chromatography. Microchem. J. 15, 60-63 (1970). 2. Sliwiok, J., On the mechanism of detectmg selected organic substances by means of fuchsine dyes and the method of thin-layer chromatography. Microchem. J. 14, 376-379
(1969).