Lecture 14 Extraction/ Identification Flashcards
(28 cards)
What is Extraction?
Extraction is a separation process transferring compounds from one phase (plant material) to another (solvent).
What factors influence method selection for extraction?
- Source material: Whole plant or specific parts, microbe cultures, etc.
- Target compound: Known or unknown, chemical stability, polarity, solubility.
- Extraction goals: Quantity needed, purity level (e.g., research vs. clinical trial scale).
What are pre-extraction considerations?
- Collect plant material based on traditional knowledge or literature.
- Identify which plant parts contain the bioactives.
- Document collection details (species, part, location, date).
- Increase surface area by powdering or chopping.
Define Maceration in extraction methods.
Maceration involves soaking coarse powder in solvent at room temperature, suitable for thermolabile compounds.
What is Infusion in extraction methods?
Infusion is steeping whole ingredients in solvent over time, suitable for volatile or readily soluble compounds.
What does Digestion refer to in extraction methods?
Digestion is maceration with gentle heating to increase yield, good for poorly soluble/polyphenolic compounds.
Describe Decoction as an extraction method.
Decoction involves boiling dried plant material (roots, bark) and is used for heat-stable, water-soluble compounds.
What is Percolation in extraction?
Percolation is where powdered plant is soaked in solvent and solvent is passed dropwise through the material.
Explain Serial Exhaustive Extraction.
Serial Exhaustive Extraction uses sequential extraction with solvents of increasing polarity to collect multiple fractions.
What is Soxhlet Extraction?
Soxhlet Extraction is a reflux extraction using a thimble packed with plant material, efficient and recycles solvent.
Define Ultrasound Assisted Extraction (UAE).
UAE uses ultrasonic waves to disrupt cell walls (cavitation), providing rapid and high yield with low solvent use.
What is Supercritical Fluid Extraction (sCO2)?
sCO2 uses CO2 above critical temperature/pressure as a solvent, suitable for non-polar compounds and thermolabile substances.
Describe Pressurised Liquid Extraction (PLE).
PLE involves pumping solvent through a sample at high temperature and pressure, allowing fast extraction.
What does Microwave Assisted Extraction (MAE) involve?
MAE uses microwaves to heat solvent and sample, speeding extraction with a short extraction time and less solvent.
What is the principle of Chromatography?
Chromatography separates compounds based on differential interactions with a stationary phase and a mobile phase.
What is Thin Layer Chromatography (TLC)?
TLC uses a polar silica gel as the stationary phase and a solvent mixture as the mobile phase to separate compounds.
Explain Column Chromatography.
Column Chromatography is scaled-up TLC where the stationary phase is packed in a column and solvent flows through.
What is High Performance Liquid Chromatography (HPLC)?
HPLC is an advanced chromatography technique using high pressure and small particle size stationary phases for fast, high-resolution results.
What are the types of HPLC?
- Analytical (qualitative & quantitative)
- Preparative (purification)
- Normal Phase (polar stationary, non-polar mobile)
- Reversed Phase (non-polar stationary, polar mobile)
- Ion exchange, size exclusion, chiral, affinity chromatography.
What practical considerations should be taken in extraction and isolation?
- Heat sensitivity favors cold or mild extraction.
- Thermostable compounds may benefit from decoction or Soxhlet.
- Solvent polarity must match target compound polarity.
- Large-scale extraction demands solvent recycling.
What is an advantage of Maceration?
Maceration is simple and good for heat-sensitive compounds.
What is a limitation of Infusion?
Infusion has low yield and is time-consuming.
What type of compounds is Decoction suitable for?
Decoction is suitable for heat-stable, water-soluble compounds.
What is a disadvantage of Soxhlet Extraction?
Soxhlet Extraction can cause heat damage.
