Sanjeet
Kumar and Itishree Sen. (2011).
Purity Determination of Menthol (Raw Material for Ointment) Through Gas
Chromatography Analysis. Emerging Science. 3(1): 22-24.
Determination of Purity Analysis of Menthol (Raw Material for Ointment) Through Gas Chromatography
Sanjeet Kumar1 and Itishree Sen2
2. Q.C.Chemist, Darex labs Pvt. Ltd. Hyderabad-38
Abstracts / Résumé
La chromatographie en
phase gazeuse (CPG) est une méthode séparative parmi les plus employées car
elle allie rapidité et efficacité de séparation. L’objectif de cet article est d’expliquer
simplement les principes de la chromatographie en phase gazeuse et l’analyse de
pureté de différent copmosés organiques par chromatographie en phase gazeuse,
ici nous avons fait l’analyse de pureté de le menthol.
Summary
The gas chromatography (GC) is a separation
method of the most used because it combines speed and separation efficiency.
The aim of this paper is to explain simply the principles of gas chromatography
and purity analysis of different organic compounds by gas chromatography, here
we have analyzed the purity of menthol.
INTRODUCTION
Menthol
Menthol is an organic
compound made
synthetically or obtained from peppermint
or other mint
oils. It is a waxy, crystalline substance, clear or white in color, which is
solid at room temperature and melts slightly above. Menthol
is widely used in a number of products and features certain therapeutic
qualities. It was first isolated from peppermint oil in 1771 in
the West, but it may have been in use in Japan for much longer
Chemistry of Menthol
Menthol (C10H20O), cyclohexanol-5-methyl-2-(1-
Methylethyl), the major constituent of peppermint oil, is a monocyclic
terpene alcohol that naturally occurs in plants of the Mentha species Menthol
has three asymmetric carbon atoms in its cyclohexane ring (Figure 1) and
therefore occurs as four pairs of optical isomers: (2)- and (z)-menthol, (2)-
and (z)-neomenthol, (2)- and (z)-isomenthol, and (2)- and (z)-neoisomenthol
(Eccles, 2000).
(2)-Menthol is the isomer that occurs most widely in nature and
produces the characteristic peppermint odor and cooling sensation when applied
to the skin and mucus membranes (Watson, Hems, Rowsell, & Spring, 1978).
The other isomers of menthol have a similar odor but do not have the same
cooling actions of (2)-menthol (Eccles, 1994, 2000).
Structure
of Menthol
Natural menthol exists as one pure stereoisomer,
In the natural compound, the isopropyl group is in the trans
orientation to both the methyl and hydroxyl groups. Menthol is the only tobacco additive promoted and advertised by the
tobacco industry.
Menthol: - A BOON
Menthol has many potential
properties like:-
v lip balms and
cough medicines
v As an
antipruritic to reduce itching
v As a topical
analgesic to relieve minor aches and pains such as muscle cramps, sprains,
headaches and similar conditions,
v In decongestants
for chest and sinuses (cream, patch or nose inhaler) Examples: Vicks Vaporub.
v In certain
medications used to treat sunburns, as it provides a cooling sensation (then
often associated with Aloe)
Material
and Methods:-
The Organic Compounds and Samples are obtained from
Darex Labs and all the analysis was done at Darex Labs Pvt. Ltd. Hyderabad -38.
The Chromatographic conditions and analysis procedures are according to Indian
Pharmacopeia 1996.
Chromatographic
condition for Menthol
Split ratio:
- 20:01
Inject
Temp.:- 220 degree Celsius
Flow rate:
- 3 ml/mint
Detector temp:
- 240 degree Celsius
Sample volume:
- 1µl
Standard volume:
- 1µl
Column –
BP5
Blank –
Isooctane.
Programme for Oven: - Initially temp 60 degree
Celsius for 0 minute and raised to 200 degree Celsius at the rate of 10 degree
Celsius par minute and hold it 5 minute at 220 degree Celsius.
Preparation
of standard:-
0.1gm of standard menthol dissolved in 10 ml
volumetric flask and make with isooctane.
Preparation
of Sample:-
0.1gm of sample menthol dissolved in 10 ml
volumetric flask and make with isooctane.
The
Purity % =
(Sample area / standard area × standard weight
/standard dilution × sample dilution / sample weight × 99.6 / 100) ×100
Results:-
Using the chromatographic conditions followed
Indian pharmacopeia 1996; found the following RT and Purity % of Menthol.
Table 1. Reading for Menthol
RT(Min)
|
Area(mV*sec)
|
Area %
|
|
Std 1
|
6.8683
|
686494.25
|
99.23
|
Sample
|
6.8017
|
62951.9125
|
98.01
|
Where,
RT –Retention Time, Purity % =
(62951.91 / 686494.25 × 0.1 /10 × 10 / 0.1 ×
99.6 /100) × 100
After calculation the purity % = 91.30 %
Conclusion:-
The Gas
Chromatography is the powerful analytical tools in analysis of compounds due to
its limiting factor, which is volatile and thermal stable, also the diversity of
modes of injection and capillary columns allows the purity analysis of chemical
compounds and metabolites. The purity % of Menthol shows the potential of GC in
purity analysis.
References
1.
Braina, K.R.,
Greena, D.M., Dykesb, P.J., Marksb, R., Bola, T.S., The Role of Menthol in Skin
Penetration from Topical Formulations of Ibuprofen 5% in vivo, Skin
Pharmacol Physiol, 2006;19:17-21.
2.
Croteau RB, Davis EM, Ringer KL, Wildung MR (December 2005). "(-)-Menthol
biosynthesis and molecular genetics". Naturwissenschaften 92 (12):
562–77
3.
CRC Handbook of Chemistry and Physics, 44th ed.
pp 2143-2184.
5.
Eccles,
R. (1994). Menthol and related cooling compounds. Journal of Pharmacy and
Pharmacology, 46, 618–630.
6.
Eccles,
R. (2000). Role of cold receptors and menthol in thirst, the drive
to breathe and arousal. Appetite, 34, 29–35.
7.
Galeottia, N., Mannellia, L.D.C., Mazzantib, G., Bartolinia, A.,
Ghelardini, C. (2002). "Menthol: a natural analgesic compound". Neuroscience Letters 322 (3):
145–148.
8.
Harris, Daniel C. (1999), "24. Gas Chromatography", Quantitative chemical analysis (Fifth ed.), W. H. Freeman and Company, pp. 675—712.
9.
Indian Pharmacopoeia. Monograph of peppermint oil.
1996.
10.
Pavia, Donald L., Gary M. Lampman, George S. Kritz, Randall G. Engel
(2006). Introduction
to Organic Laboratory Techniques (4th Ed.). Thomson Brooks/Cole. pp. 797–817.
11.
L. T. Sandborn, "l-Menthone",
Org. Synth.,http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv1p0340; Coll. Vol. 1: 340
12.
Watson,
H. R., Hems, R., Rowsell, D. G., & Spring, D. J. (1978). New compounds with
the menthol cooling effect. Journal of Cosmetic Chemistry, 29,
185–200.
13.
J. L. Simonsen (1947). The Terpenes, Volume I (2nd ed.). Cambridge University Press.
pp. 230–249.
14.
M. Moriya (1881). "Contributions from the Laboratory of the University
of Tôkiô, Japan. No..
