HomeThin Layer ChromatographyThin Layer Chromatography Identification Test for Dextromethorphan following European Pharmacopeia Monograph on Silica Gel G 254 Plates
Thin Layer Chromatography Identification Test for Dextromethorphan following European Pharmacopeia Monograph on Silica Gel G 254 Plates
Introduction
Dextromethorphan is a drug of the morphinan class. It is a cough suppressant with sedative, dissociative, and stimulant properties (at higher doses) and it is the active ingredient in many over-the-counter cold and cough medicines.
This application note illustrate how Silica Gel G plates are suitable for the analysis of Dextromethorphan following the European pharmacopeia identification TLC test experimental conditions (version 9.0).
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Figure 1.Dextromethorphan Hydrobromide
TLC Plate | Silica Gel 60G F254 20 x 20 cm | Injection volume | 5 µL |
Detection | Spray with potassium iodobismuthate solution R2 (Potassium iodobismuthate solution: Suspend 1.7 g of bismuth subnitrate R and 20 g of tartaric acid R in 40 mL of water R. To the suspension add 40 mL of a 400 g/L solution of potassium iodide R and stir for 1 h. Filter. The solution may be kept for several days in brown bottles. Mix immediately before use 5 mL of the stock solution with 15 mL of water. | ||
Mobile Phase | Concentrated ammonia: methanol : methylene chloride : ethyl acetate : toluene 2:13:10:20:55 (v/v/v/v/v ) | ||
Development | Over 2/3rd of the plate | ||
Diluent | Methanol | ||
Drying | In air | ||
Standard | Dissolve 25 mg of standard timolol maleate in methanol and dilute to 10 ml with the same solvent | ||
Sample | Dissolve 25 mg substance to be examined in methanol and dilute to 10 ml with the same solvent. |
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Figure 2.TLC plate development
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Figure 3.Chromatograms
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Figure 4.Spectrum
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Figure 5.Chromatographic Data (Standard Solution)
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Figure 6.Chromatographic Data (Sample Solution)
Compound | Rf | |
---|---|---|
1 | Dextromethorphan | 0.29 |
Compound | Rf | |
---|---|---|
1 | Dextromethorphan | 0.29 |
STD 1 | 2363 |
STD 2 | 2347 |
STD 3 | 2494 |
STD 4 | 2453 |
STD 5 | 2461 |
Mean | 2423.6 |
Standard Deviation | 64.7 |
RSD (%) | 2.7 |
- The principal spot in the chromatogram obtained with the test solution is similar in position, colour and size to the principal spot in the chromatogram obtained with reference solution.
- All the spots for the reference solution have a repeatability better than 3% RSD.
- Merck silica gel G plates provides repeatable and reproducible results for Dextromethorphan identification test and comply to all requirements as per European Pharmacopoeia.
Materials
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