CHM 510 – ANALYTICAL SEPARATION METHODEXPERIMENT 10 – Qualitative Analysis of Ginger by Gas Chromatography – Mass Spectrometry (GC-MS) Done on 28th March 2014 By ASHRAF BIN AHMAD 2012706315 ABDUL IZZULISLAM BIN ABDUL HAMID 2013433056 MOHD MAUSA JASNIME BIN NAZRI 2013161343 For Dr. Tay Chia Chay Submission date: 4th April 2014 Many compounds such as antimicrobial. the organic layer was supposed to be transferred into a beaker and dried with anhydrous magnesium sulphate to remove excessive water. Then the solution was transferred to a separating funnel and extraction is done using dichloromethane. cytostatic and therapeutic activities. and environmental samples. With the chromatograms and related mass spectra obtained. antimicrobial. This technique consumes a lot of time and involve a large waste of solvent. It is necessary to take care when a drug is prepared for a complete extraction of the active principles from plants. herbal medicines.Introduction In this experiment. insecticidal. Ginger is widely used as either a food product or an herbal medicine in our life. Then the mixture was supposed to be filtered and put into a vial for qualitative analysis using GC-Mass Spectrometry (GC-MS). and diuretic compounds can be isolated from a single herb. sedative. The chopped up ginger was then refluxed for 30 minutes. Plant extract have been used by humans for their antifungal. To perform an extraction of ginger by liquid-liquid extraction. Objective 1. the chemical components can be qualitatively identified based on the similarity searches in the MS databases. we want to perform an extraction of ginger using liquid-liquid extraction (LLE) technique to analyse and to identify the constituents in the essential oil of ginger by using gas chromatography (GC). GC-MS has good ability in separation technique and assist qualitative and quantitative determination of chemical components separated from complicated practical systems such as foods. otherwise they can be destroyed in the extraction process with the decrease and even loss of therapeutical activity. To analyze and identify the constituents in the essential oil of ginger by using GC-MS . The therapeutical activities of herbs depend on some ‘vegetal active principle’ contained in the plants. antiseptic. When the solution formed two layers. The ginger used is about 8g and was dissolved in a methanol solution. In this experiment. Conventional sample preparation technique based on liquid-liquid extraction (LLE) have been widely used to separate analyte from sample matrix and to preconcentrate trace compound. 2. we want to determine volatile components in essential oils from ginger by use of gas chromatography-mass spectrometry (GC-MS). Instrument Gas chromatograph (Agilent Technologies 6890N) equipped with a 5% poly(phenylmethylsiloxane) capillary column (30m X 0. 250 mL separating funnel 3. Dichloromethane 3. Methanol 2. 50 mL beaker and sample bottle.25mm) and a 5972 MSD Quadrupole detector . 13 mm diameter syringe filter (0.Reagents 1. Anhydrous magnesium sulphate Sample Fresh ginger Apparatus 1. Round-bottom flask 2. West condenser 4.45 mm pore size) 5. - The mixture was then filtered by using filter funnel.Procedure 1. - Then the solution was transferred into a separating funnel and added with 5 ml of dichloromethane. - Then the sample was refluxed for about 30 minute. Instrument set-up. - Then 25 ml of methanol was added to the flask. - Then the ginger was chopped into small pieces and put into a round bottom flask. - Then the organic layer was drained into a beaker and added with anhydrous magnesium sulphate. - The final product was filtered to remove any particulate matter and put into vial for analysis by using GC. 2. Then ramp the temperature at 10°C/min up to 140°C and 20°C/min to 280°C - Column flow rate : 40 mL/min - Detector temperature : 290°C . - Injection port : Split (20:1) - Injection port temperature : 280°C - Oven temperature : initial temperature 70°C for 4 min. Sample preparation - 3-4g of ginger was weighed and recorded. The line seen in the pictures shown illustrates an alteration in color in the two layers because the oil has been extracted by the extracting solvent. However. Hence.89g. which is dichloromethane. the essential oil may slip back into the extracted layer due to two reasons. ginger was used instead of spearmint herbs because unlike spearmint herbs. which is miscibility between the two . First of all. Discussion A few modifications were made to this experiment that differed from the manual. a clear and separated line between these two solvents does not exist. temperature ramping conditions may be altered to optimize the resolution. almost twice the number stated in the manual. ginger is widely available and rather cheap. - Identify the major compounds in the extract by comparing their mass spectra with the flavor library in the GC-MS database. but no line between the two solvents is visible. and the extracted layer. One is as mentioned above. they are both miscible to each other. The extracting layer. Results No result was obtained from this experiment as the amount of essential oil extracted from the ginger is too small to be separated and used in any analysis.3. which is methanol. But that was not the case. This experiment was run with 7. Separation of essential oils in spearmint herb. are both organic solvents. - Inject 2 μL of each sample extract. Identifications of essential oil constituents in each sample extract. The initial mass of sample stated in the manual is three to four grams. as shown in the pictures inserted. When the extracted layer is to be drained. and no other method was available at the time to get a better extraction in terms of volume and purity. in hope that extraction could be more effective. If necessary. This substitution does not require any change to the methodology used. a large portion of ginger is needed to ensure that extraction is possible. 4. This is where the second modification came to use. Being organic solvents. methanol has a higher polarity index of 5.1 compared to dichloromethane’s polarity index of 3. Extracting solvent (Dichloromethane + Extracted solvent One solution to this problem is to increase the mass of sample used. However.1. with the predicted dipole moments of 1. Although both are polar solvents. as the polarity of the solvents still affects the . This shows that methanol may likely retain or reverse-extract the essential oils back into its body of fluid. and can only help so much in volume. the greater the volume of essential oil extracted.solvents. this is only a stop-gap solution which may not prove handy when other types of samples are used.882 Debye and 1. not purity. Another reason which may greatly affect the extraction is the polarity of these two solvents. The higher the mass of ginger used.807 Debye for methanol and dichloromethane respectively. as the cooler of the rotavap available cannot handle such long periods of usage. geraniol. These compounds can be predicted through extensive search of results of analysis done on ginger by other people. the initial solvent may be the one changed. Among the chemical compounds usually found in the essential oil of ginger is a-pinene. linalool. Another solution is to change the solvent used. borneol. Prolonged operation times are not good as it leads to excessive and wasteful energy use and may break the machine itself. The best solution is to modify the extraction process. neral. b-pinene. the purity of the sample is very questionable. the rotavap available at the time this experiment was held has suction problems which will prolong operation time. geranyl acetate. Even if extraction is done. After that. we can still predict the expected compounds that may be identified by the GC-MS. the choices had been narrowed down to only one. transferred into a sample vial using a syringe equipped with a 0. Rotavaps are very useful and efficient in collecting small amounts of product from a solvent-containing mixture. y-terpineol. due to a series of unforeseen misfortune. In fact.45mm pore filter. Although the experiment was halted midway. b-bisabolene and zingiberene. it is possible to get the crude essential oil using steam distillation or a rotary evaporator (Rotavap).extraction. which is more eco-friendly compared to LLE and less tedious. the experiment may yield better results. geranial. either using a more polar solvent during extraction or using a solvent that is immiscible to the initial solvent. However. analyzed using the GC-MS. . the essential oil must be filtered. which is using the rotavap. If given a rerun with a rotavap in good condition. Rather than using liquid-liquid extraction. Since setting up a steam distillation set is not possible in the lab. Using water as the initial solvent may not be a good choice as it has a higher boiling point than methanol. nerol. Therefore. camphene. 1. a minimum amount of anhydrous magnesium sulphate must be used in order to absorb excessive moisture from the oil. Another good point of rotavaps is that it does not require the use of an extracting solvent. After collecting the essential oil. It is at this point that the experiment was halted as extraction using the current sample is near to impossible.8-cineole. and more heat may lead towards the deterioration of the sample. and lastly. Having a higher boiling point means that water needs more heat to be boiled. it is better to not do any extraction given the situation. pdf http://infohost.edu/~jaltig/SteamDistill.my/461/1/KHAIRU_AIZAM_BIN_IBRAHIM_2049. However.essentialoils.answers. therefore the experiment is a failure.com/question/index?qid=20091003063830AAFSL4l . Reference http://www.pdf http://agritech.pdf http://macro.nmt.in/horticulture/extraction_methods_natural_essential_oil.edu.yahoo.ac.htm http://umpir.edu/howto/solvents/Polarity%20index.htm https://au. problems with the method used for this experiment has been identified.Conclusion The experiment did not meet its objective.ump.tnau. and further improvements can be implemented in order to get better results in the future.co.za/essential-oils/ginger.lsu.
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