32 Questions
What is a major advantage of modern sample preparation techniques compared to traditional methods?
Reducing the consumption of organic solvents and minimizing sample degradation
What is eliminated from the extract as a result of modern sample preparation techniques?
Undesirable and insoluble components
Which of the following is a characteristic of Soxhwave extraction?
It combines the rapid heating capacity of microwaves with the simplicity of Soxhlet
What is a common feature of modern sample preparation techniques such as microwave-assisted extraction, supercritical fluid extraction, and ultrasound extraction?
They are all designed to reduce the consumption of organic solvents
Which of the following techniques is NOT a type of modern sample preparation technique?
Soxhlet extraction
What is the primary factor in determining the type of extraction method?
The physical and chemical properties of the phytochemical
What is the significance of considering the part of the plant used in extraction?
It affects the yield of the active ingredient
Why is the nature of the plant material (fresh or dry) important in extraction?
It affects the solubility of the phytochemical
What is a key consideration when selecting an extraction method for a heat-sensitive phytochemical?
The temperature of the extraction process
What property of the phytochemical can affect the choice of solvent in extraction?
Solubility
What is the primary factor that affects the quality of extraction when dealing with dry or fresh plant material?
Nature of the drug
Which of the following factors does NOT affect the quality of extraction?
Humidity
What is the ideal characteristic of a solvent in terms of its reaction with the extracted compound?
Non-reactive
What is the primary advantage of using a solvent that is highly selective for the compound being extracted?
It improves the quality of the extracted compound
What is the main disadvantage of most small-scale extraction processes of maceration and percolation?
They are slow and time-consuming
What is the primary consideration when choosing a solvent in terms of its economic feasibility?
It should be economically available
What is the primary benefit of using a solvent that is harmless to humans and the environment?
It ensures the safety of the operators and the environment
What is the primary factor that accelerates the extraction procedure in hot extraction methods?
Temperature
Which type of extraction method is more time-consuming?
Cold extraction method
What is the primary reason for increasing the temperature during the extraction process?
To increase the solubilization process
What is the characteristic of an infusion?
It is a type of periodic maceration of the drug with either cold or boiling water
What is the primary difference between the percolation and maceration methods?
The flow of solvent through the powered drug
What type of plant ingredients are generally used in hot extraction methods?
Those that are not affected widely by heat
What is the result of the percolation process compared to the maceration process?
Products of greater concentration
What is the purpose of leaving the material in the vessel for 24 hours?
To allow the material to soak in the solvent
What type of extraction method is infusion an example of?
Periodic maceration method
What is the purpose of using a Clevenger apparatus?
To extract volatile compounds
Why is the Clevenger method suitable for certain plant materials?
Because it does not significantly affect heat-sensitive plants
What happens to the plant material and water in the Clevenger process?
They are placed in the distillation round flask
What type of compounds are typically extracted using the Clevenger method?
Volatile compounds
What is the relationship between the boiling points of two immiscible liquids?
They are less than the boiling points of each individual liquid
What is the significance of Dalton's law of partial pressure in the context of immiscible liquids?
It explains the boiling points of immiscible liquids
Study Notes
Modern Extraction Techniques
- Modern extraction techniques have several advantages compared to traditional methods, including reduced consumption of organic solvents and reduced degradation of samples.
- These techniques include Microwave-assisted Extraction, Supercritical Fluid Extraction, Counter-Current Extraction, Ultrasound Extraction (Sonication), and Soxhwave.
- Soxhwave is a combination of Soxhlet with microwaves, combining rapid heating capacity with simplicity.
Factors Affecting Extraction
- Nature of the drug (dry or fresh plant) affects the quality of extraction.
- Solvent suitability to dissolve required ingredients affects extraction quality.
- Temperature and agitation increase the solubilization process.
- pH affects the extraction process, depending on the nature of the extracted product.
- Particle size affects the surface area, thus improving extraction.
- Time affects the extraction process or stability of ingredients.
Choosing the Ideal Solvent
- The solvent should be highly selective for the compound being extracted.
- The solvent should not react with the extracted or any other compound within the plant material.
- The solvent should be economic and available.
- The solvent should be harmless to humans and the environment.
Extraction Methods
- Most small-scale extraction processes of maceration and percolation are slow and time-consuming, giving inefficient extraction of crude drugs.
- Choosing the type of extraction method depends on the nature of the plant (fresh or dry, and the part used) and the active ingredient being extracted.
- The physical and chemical properties of the phytochemical, including solubility, chemical nature, and susceptibility to heat, affect the extraction method.
Percolation Process
- The percolation process depends on the flow of solvent through the powered drug, yielding products of greater concentration than the maceration process.
Hot Extraction Methods
- These methods are generally used for plant ingredients that are not widely affected by heat.
- These methods are less time-consuming than cold extraction methods, as temperature accelerates the extraction procedure.
Infusion
- An infusion is a dilute solution of the readily soluble constituents of crude drugs.
- It is a type of periodic maceration of the drug with either cold or boiling water.
Clevenger
- Clevenger is a distillation extraction process using a special apparatus.
- This method is mainly used to extract volatile compounds.
- The plant material and water are placed in the distillation round flask, and the process is applied to plants that are not significantly affected by heat.
Learn about the advantages of modern sample preparation techniques, such as microwave-assisted extraction and supercritical fluid extraction, over traditional methods, including reducing solvent consumption and eliminating undesirable components.
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