Steam Distillation of (S)-(+)-Carvone from Caraway Seeds and (R)-(-)-Carvone from Spearmint Leaves. Analysis of Products by Infrared Spectroscope and TLC
Methods/Backgrounds:
In this experiment we had to isolate (S)-(+)-Carvone from Caraway Seeds and (R)-(-)-Carvone from Spearmint leaves via steam distillation and by extracting
the distillate with CH2Cl2. We analyzed the samples/enantiomers by using infrared spectroscopy, Bayer test, and TLC.
In the liquid phase, the molecules are constantly in motion, and some of them at the top escape to vapor phase. A dynamic equilibrium is when the number of gas molecules exiting/entering the liquid phase is in equilibrium. The liquid vapor pressure is the pressure gas molecules push against the walls
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These two compounds have the same bp, mp, densities, color, viscosity, infrared spectra, TLC and gas chromatography, so the only way to differentiate them is by its polarimetry and scent. The (R)-(- )-Carvone smells like spearmint and is found in spearmint oil which also contains minor amount of limonene. Comparatively, (S)-(+)-carvone is found in caraway seeds and also contains limonene. Both of these enantiomers are not natural nor readily available. However, via distillation they can be isolated.
Distillation is a technique used for separating, identifying and purifying liquids. Simple Distillation and fractional distillation are often used for isolation of mixture of liquids. In this experiment, steam distillation is used to separate carvone from caraway seeds and spearmint leaves. For steam distillation, the bp has to be less than 100° C, compound mixed with water has to be stable at 100° C.The principles of steam distillation focus on Raoult’s law and Dalton’s law. However, since it is not soluble in water, it does not depend on its mole fraction in the mixture. Therefore, Raoult’s law does not apply to steam distillation because the compounds are immiscible, so they do not depend on each other’s mole fraction. According to Dalton’s law total vapor pressure is higher than most volatile component and boiling point mixture is lower
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The resulting spots from all three samples traveled about same distance. There were three big spots muddy brown in color. Out of the three main muddy spots, there were also some yellowish spots observed for the spearmint leaves extraction sample and co-spot mixture sample. Knowing that both of the enantiomers contain Limonene, these yellowish spots probably indicate presence of Limonene. The location of the spots indicates the affinity of the compound to specific phase. The muddy spots observed were close to each other at similar distance from the baseline. This indicates that the compounds were less polar and had greater affinity to the mobile phase and quickly moved up the plate with larger retention factors. Also, more polar compounds in the sample have greater affinity to the stationary phase and therefore move slowly with smaller retention factors. This findings suggest that Carvones are less polar compared to limonene, which is somewhat more polar because it was found in the middle of baseline and muddy spots. This reasoning is supported by the calculated retentions factor. The Rf for the Spearmint leaves for the three samples were calculated to be: pure (R)-Carvone
Experiment 55 consists of devising a separation and purification scheme for a three component mixture. The overall objective is to isolate in pure form two of the three compounds. This was done using extraction, solubility, crystallization and vacuum filtration. The experiment was carried out two times, both of which were successful.
Lycopene and β-carotene are separated using thin layer chromatography (TLC). A mixture of tomato paste containing dissolved lycopene and β-carotene is first spotted on a TLC plate. The technique uses a stationary phase layer, on which the substances stick, and a mobile phase, which migrates upwards the plate and carries the components of the mixture with itself (Chemguide). Depending on their respective polarity, lycopene and β-carotene stick more or less to the stationary phase and so they migrate up the TLC plate at different rates (Chemguide). Thus, as the chromatography is completed, the two components will appear as distinct dots at different heights on the plate. Lycopene has a bright orange color, whereas β-carotene is light yellow.
An example of those are carnosic acid, rosmarinic acid and caffeic acid, possessing strong antioxidant, radical-scavenging, and antibacterial activities. The majority of the phenolic acids in Sage species are derivatives of caffeic acid which is the building block of a variety of plant metabolites. Caffeic acid plays a central role in the biochemistry of the Lamiaceae plants, and occurs mainly in a dimer form as rosmarinic acid. Carnosic acid and rosmarinic acid, which are present at high concentrations in the extract of Sage plants, have shown strong antioxidant properties. Ursolic acid, also a component of sage, has strong anti-inflammatory properties, and in sage preparations, it is considered as a quality control measurement for the anti-inflammatory effects of different
There are millions of different organic compounds. Most of them are found in mixtures and in order to achieve a pure form they need to be separated, isolated, and purified. However, there are endless numbers of possible mixtures, which make it impossible to have a pre-designed procedure for every mixture. So chemists often have to make their own procedures. The purpose of this experiment was to prepare the student to the real world by them designing their own procedure which will help them understand the techniques of separation and purification better. The goal was to extract two of the components of the
Abstract: One mixture of two unknown liquid compounds and one mixture of two unknown solid compounds were separated, isolated, purified, and characterized by boiling point. Two liquid unknowns were separated, isolated, and purified via simple distillation. Then, the process of an acid-base extraction and washing were used to separate two unknown compounds into two crude compounds: an organic acid and a neutral organic compound. Each crude compound was purified by recrystallization, resulting in a carboxylic acid (RCO2H) and a pure organic compound (RZ). The resulting mass of the pure carboxylic acid was 1.688g with a percent recovery of 31.80%, the boiling range was 244-245 °C, and its density was 2.0879g/mL. The resulting mass of the pure organic solid was 2.4902g with a percent recovery of 46.91%, the boiling range was 52.0-53.4°C, and its density was 1.5956 g/mL.
With a 9-inch pipet was used to add water through the condenser to keep the flask no more than half way full. Clove oil was extracted from the distillate in 1 mL increments every 5 to 10 minutes. The distillation and extraction process was approximately 37 minutes with 7 mL of distillate recovered. The product recovered was a light yellow liquid color with the same strong, sweet, cinnamon odor as the raw clove. 1 mL of dichloromethane solution was used to rinse the Hickman still and was then transferred to the centrifuge tube. Another 2 mL more of dichloromethane was added and shaken vigorously. Upon shaking the the mixture turned a cloudy white color with two layers resulting. The major component of clove oil was extracted with two more 3 mL portions of dichloromethane solution. The mixture was allowed to cool and left in the hood overnight to dry.
1.) Briefly explain the concept of steam distillation. What is the difference between a simple distillation and a steam distillation? When a mixture of two immiscible liquids are distilled it is referred to as codistillation. This process is referred to as steam distillation when one of the liquids is water. This distillation is used to separate organic liquids from natural products and reaction mixtures in which the final product results in high boiling residues such as tars, inorganic salts, and other relatively involatile components. It is useful in isolating volatile oils from various parts of plants and not useful in the final purification of a
Distillation is a method of separating two volatile chemicals on the basis of their differing boiling points. During this lab, students were given 30 mL of an unknown solution containing two colorless chemicals. Because the chemicals may have had a relatively close boiling point, we had to employ a fractional distillation over a simple distillation. By adding a fractionating column between the boiling flask and the condenser, we were able to separate the liquids more efficiently due to the fact that more volatile liquids tend to push towards the top of the fractionating column, thereby leaving the liquid with the lower boiling point towards the bottom. After obtaining the distillates, we utilized a gas chromatograph in order to analyze the volatile substances in the gas phase and determine their composition percentage of the initial solution. Overall, through this lab we were able to enhance our knowledge on the practical utilization of chemical theories, and thus also demonstrated technical fluency involving the equipment.
The light yellow precipitate was collected by suction filtration using a Hirsch funnel. The product was washed with two 1-mL portions of cold methanol followed by two 1-mL portions of diethyl ether. The product was dried in the oven at 110°C. The IR spectrum as a KBr pellet was obtained for the product and inosine for analysis.
The isolation of β-carotene from lycopene via column chromatography was accomplished, but results were inconsistent. Many students were unable to isolate the first elution compound, β-carotene; however, lycopene isolation was very obtainable; due to the structural similarity of these two molecules, it was intuitive that a separation would be difficult. UV/VIS and TLC analysis of the compounds confirmed that it is possible to isolate β-carotene from lycopene, due to differences in dipole moments of these chemicals. In future experiments, it is suggested to use a mobile phase less polar than 15% ethyl acetate and 85% hexanes such as 5% ethyl acetate and 95% hexanes, for this would have potential to create a better separation. It was
In vitro enzyme-inhibitory assay-guided fractionation of Polygonum hyrcanicum extract resulted in the purification of 13 phenolic compounds as the active constituents. Based on NMR data, the purified compounds of Polygonum hyrcanicum were identified as quercetin (1) [17], myricetin (2) [17], N-trans-caffeoyl-tyramine (3) [18], quercetin 3-O-α-L-(3",5"-diacetyl-arabinofuranoside) (4) [19], quercetin 3-O-α-L-(3"-acetyl-arabinofuranoside) (5) [20], myricetin 3-O-α-L-(3",5"-diacetyl-arabinofuranoside) (6) [21], (+) catechin (7) [22], (-) gallocatechin (8) [22], myricetin 3-O-β-D-galactopyranoside (9) [23], myricetin 3-O-α-L-rhamnopyranoside (myricitrin) (10) [23], quercetin 3-O-β-D-galactopyranoside (11) [24], myricetin 3-O-α-L-arabinofuranoside
An ester was synthesized during an organic reaction and identified by IR spectroscopy and boiling point. Acetic acid was added to 4-methyl-2-pentanol, which was catalyzed by sulfuric acid. This produced the desired ester and water. After the ester was isolated a percent yield of 55.1% was calculated from the 0.872 g of ester recovered. This quantitative error was most likely due to product getting stuck in the apparatus. The boiling point of the ester was 143° C, only one degree off from the theoretical boiling point of the ester 1,3-dimethylbutyl, 144 ° C. The values of the
The purpose of this experiment was to use solvent extraction techniques in order to separate a mixture consisting of a carboxylic acid (p-toulic acid), a phenol (p-tert-butylphenol), and a neutral compound (acetanilide). Extraction is the process of selectively dissolving one or more of the compounds of a mixture into an appropriate solvent, the solution that contains these dissolved compounds is called an extract (Manion, 2004).
The modern technique of steam distillation is created by the Persian physician Avicenna (Power). It has been documented that he lived during the time of 980 - 1036 of common era (CE). His first documented distilling was of roses and he succeeded in completing the process in the first round.. This became evident that distilling techniques were being used earlier than Avicenna's time. Recently discovered a Greek historian Herodotus who was estimated to be alive during 484 BCE mentions oils turpentine and give partial information about its productions. The history of distillation of aromatherapy is until the middle ages, distillation was only flower water. It is still unclear who created the modern process of distillation.
For this experiment, Alcohol D and Acid 2 reacted in the presence of concentrated sulfuric acid, resulting in a colorless solution with brown layer on top. After washes with sodium bicarbonate and brine, the pale-yellow liquid product was dried and then distilled. Distillation resulted in two colorless fractions, the second of which had a boiling point of 69-70 ˚C. This boiling point is unrealistic for any compound obtained in this experiment, so it was not used in identifying the product. After distillation, both fractions were spectroscopically analyzed. The IR and NMR spectra obtained for both fraction were identical, meaning both fractions contained exactly the same substance. Both fractions also smelled the same, like piña colada, therefore confirming this conclusion. This outcome also meant that the amount of product synthesized was 5.7393 g.