Lab report experiment 5- Liquid CO2 of D- Extraction Limonene from Orange Rind PDF

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Liquid CO2 of D- Extraction Limonene from Orange Rind
This is about the process of extracting the orange essential oil from an orange rind using solid co2...

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Idelise Melendez Experiment 5 Lab Report: Liquid CO2 Extraction of D-Limonene from Orange Rind

I.

II.

Set up a hot water bath. Heated water to approximately 45-50°C. Did not exceed 50°C.

INTRODUCTION: i. Background: Terpenoids are large and diverse groups of lipids that derive from five carbon isoprene units (1). Terpenoids are not to be confused with terpenes. Terpenoids contain oxygen whereas terpenes contain hydrocarbon. The term terpenoid is an umbrella for five different subunits. Terpenoids can be divided into monoterpenes, sesquiterpenes, diterpenes, sesterpenes, and triterpenes. (2). In this experiment, D-limonene was used. D-limonene is the essential oil that can be extracted from limonene and it can be classified as a monoterpene. This experiment aimed to extract the essential oil, D-limonene, from an orange rind using liquid CO2. To do this, a centrifuge tube is used. A copper wire is placed in the centrifuge tube and a piece of paper is placed on top of the copper wire to maintain the orange rind on the top of the copper wire. The centrifuge tube is then filled with ice and capped. This tube is then placed in a cylinder with heated water and the essential oil is slowly extracted from the orange rind as the dry ice melts. The melted dry ice is essentially liquid CO2. Liquid CO2 is used in this experiment because of the benefits. These benefits are as follows: it is environmentally safe and nontoxic. This makes it easily to obtain and not harmful to the environment as well as those working in the lab. Once the extraction of Dlimonene is completed, the polarimetry of the D-limonene is observed. Polarimetry is a measure of the extent to which a substance can interact with plane-polarized light (3). Polarimetry is directly connected to a term called chirality. Chirality is used to explain molecules that are mirror images of each other, yet they are not superimposable. This is important to understand for this experiment because of polarimetry. Chiral molecules will only react with chiral molecules. In a polarimetry test, light is placed through a polarizer with the substance and the optical rotation is observed. Optical rotation is the angle of rotation that the plane-polarized light goes through after it has been passed through a substance. If there is an angle of optical rotation, it can be inferred that the substance being tested is chiral. To understand which substance, or enantiomer, is in excess, the angle of optical rotation is looked at. As a pure substance, each enantiomer is labeled with a positive and negative value—the value will be the same and the only difference will be sign. If the optical rotation is positive, then the enantiomer in excess will be the substance with a positive pure rotation. This is the same for a negative optical rotation. EXPERIMENTAL SECTION: i. Procedural Flowchart: a. Liquid CO2 Extraction of D-Limonene from Orange Rind

Weighed a 50mL centrifuge tube

Inserted a copper ring (after making 3-4 coils) in centrifuge tube.

Placed a piece of paper on top of the copper ring.

Moved the heated water to a clear plastic cylinder and placed the centrifuge tube in the cylinder.

Observed the extraction of D-Limonene from the orange ring

When all of the dry ice melted, observed limonene and carefully released pressure.

b.

c.

Used a cheese grater to zest the rind of an orange.

Dried the outside of the centrifuge tube and determined mass, smell, and color of the extracted oil.

Polarimetry Procedure

Added 1mL of ethanol to tube and dissolved. Combined all ethanol solutions and placed in a 10mL volumetric flask.

Utilized planepolarized light. Weighed the remainder of limonene extract.

Placed 2-3 drops of DLimonene on a measuring prism using pipette. Closed lid.

Added 12g of orange zest into the centrifuge tube by loosely packing. Filled the remaining space with dry ice. Placed cap on the centrifuge tube tightly.

Added solution to sample tube and observed rotation. Calculated specific rotation and enantiomeric excess.

Refractive Index Procedure

Turned index adjuster to align contrast line with cross hairs. Read refractive index

Corrected reading to 20°C and added correction to value obtained.

III.

TABLE OF CHEMICALS: i. Table 1- Chemicals used during experiment D-Limonene

Name Formula

Ethanol

C10 H 16

Dry Ice (Carbon dioxide, solid)

C H 3 C H 2 OH

C O2

Structure

136.24 g/mol

46.07 g/mol

44.01 g/mol

Melting Point

-74.35 °C

-114.1 °C

-78.5 °C

Boiling Point Hazards

176 °C

Molecular Weight

Flammable IV.

78.5 °C

-78.5 °C

Flammable

No apparent hazards

RESULTS i. Table 2- Results from experiment Refractive Index Optical Rotation Mass of Orange Rind Mass of D-Limonene Odor Percent Yield Specific Rotation Enantiomer Excess

1.4644 +10.5° 10g 0.2g Citrus/Orange 2% 525° 424%

ii. Calculations a. Percent yield0.2g/10g x 100= 2% b. Specific Rotation +10.5°/0.02 = 525° c. Enantiomer Excess 525/123.8 x 100= 424% d. Refractive Index 1.4727 + 0.00045(28-20) = 1.4644 V.

DISCUSSION i. This experiment aimed to completely extract D-Limonene from an orange rind using liquid CO2. While completing this experiment, there were lots of apparent benefits of using CO2. CO2 is environmentally friendly and nontoxic. It can also

VI.

VII.

be found anywhere, making it readily available. This can be useful because it allows for experiments such as these to be completed without having to take many extra-ordinary measures to acquire all necessary materials. It is also a benefit that CO2 is able to extract the essential oils from natural resources because of the aromatherapeutic advantages that essential oils carry. This method also minimizes waste and energy consumption compared to the traditional steam distillation system. The steam distillation system needs relatively high temperatures to complete the distillation with steam. This can be harmful to the scientists working with this distillation system and can also pose a problem of possibly denaturing the element at hand. If the temperature is too high for the compound being studied, this can cause for more of the compound to be lost in energy and evaporation—this causes for the results to be skewed. This method is able to achieve the same results without having to use high temperature and steam. Looking at table 2, it should be noted that the optical rotation is +10.5° and the specific rotation is 525°. The optical rotation was expected; however, it was not expected to get a specific rotation over 100. The compound was able to refract the light continuously, giving the specific rotation over 100. The enantiomeric excess, as seen in table 2, is 424%. This result exceeds 100 and it can be due one enantiomer completely taking over the other. This causes for the rotation to only favor the enantiomer in excess while ignoring the other enantiomer. The refractive index of the D-limonene in this experiment was 1.4644. The literature value is 1.473. The experimental value is extremely close to that of the literature value, meaning that the results are accurate. The small discrepancy in the values can be due to the small sample size used during this experiment. If the sample size was much larger, the refractive index would have been different. CONCLUSION i. The theoretical background and the results obtained were connected. The theoretical background noted that CO2 liquid was the best way to achieve was this experiment was set out to do. This liquid was able to extract the D-limonene from the orange rind zest and observe its refractive index as well as its polarimetry. The experimental data revealed that the experiment was a success, and the results were accurate according to the literature values. This experiment can also be generalized to other situations apart from those in this lab. CO2 liquid can be used to extract many different essential oils, which are used for therapeutic relief for many men and women today. The techniques here can be used to extract oils from tree leaves as well as the oils from many other citrus fruits. Overall, this experiment accomplished what it was set out to do. REFERENCES 1. Terpenoids, https://chem.libretexts.org/Courses/Athabasca_University/Chemistry_360%3A_ Organic_Chemistry_II/Chapter_27%3A_Biomolecules_-_Lipids/27.05_Terpenoids (accessed Feb 18, 2021). 2. Introductory Chapter: Terpenes and Terpenoids, https://www.intechopen.com/books/terpenes-and-terpenoids/introductorychapter-terpenes-and-terpenoids (accessed Feb 18, 2021).

3. Polarimetry, https://chem.libretexts.org/Courses/Purdue/Purdue %3A_Chem_26505%3A_Organic_Chemistry_I_(Lipton)/Chapter_5._Spectroscopy /5.5_Polarimetry (accessed Feb 18, 2021)....