Basic tests for medicinal plant materials are essential for B.Pharm students to ensure the identity, purity and safety of herbal drugs. This concise guide covers organoleptic evaluation, microscopic identification, and key physicochemical parameters such as loss on drying, total ash, acid-insoluble ash and extractive values. It also reviews common phytochemical screening tests for alkaloids, glycosides, flavonoids and saponins, plus analytical techniques like TLC/HPTLC, heavy metal analysis and microbial limits. Mastery of these tests supports quality control, detection of adulteration, formulation development and regulatory compliance in pharmacognosy. These fundamentals are vital for practical lab work, formulation development and research in pharmacognosy. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. What is the primary purpose of basic tests for medicinal plant materials?
- To assess identity, purity and quality of herbal drugs
- To determine market price
- To teach botanical taxonomy only
- To replace clinical trials
Correct Answer: To assess identity, purity and quality of herbal drugs
Q2. Which organoleptic characteristics are routinely used in preliminary evaluation of crude plant drugs?
- Taste, color, odor and texture
- pH only
- Microscopic cell types only
- DNA barcode sequence
Correct Answer: Taste, color, odor and texture
Q3. Microscopic examination of powdered plant material primarily helps to identify which of the following?
- Diagnostic cellular structures like trichomes, stomata and vessels
- Total ash content
- Alcohol-soluble extractive value
- Heavy metal concentration
Correct Answer: Diagnostic cellular structures like trichomes, stomata and vessels
Q4. Loss on drying (LOD) is a test used to determine what parameter in plant materials?
- Moisture and volatile matter content
- Total inorganic residues
- Alkaloid presence
- Chromatographic purity
Correct Answer: Moisture and volatile matter content
Q5. What does total ash value represent in quality control of herbal drugs?
- Total inorganic residue remaining after incineration
- Amount of organic active constituents
- Microbial load in the sample
- Water content of the sample
Correct Answer: Total inorganic residue remaining after incineration
Q6. Which ash parameter indicates contamination with silica, sand or glass?
- Acid-insoluble ash
- Water-soluble ash
- Loss on drying
- Alcohol-soluble extractive value
Correct Answer: Acid-insoluble ash
Q7. Water-soluble ash is useful to estimate which aspect of plant material?
- The amount of inorganic matter soluble in water
- The content of alkaloids
- The total carbohydrate content
- The level of essential oils
Correct Answer: The amount of inorganic matter soluble in water
Q8. Alcohol-soluble extractive value helps estimate what in a crude drug?
- Amount of active constituents extractable with alcohol
- Total ash content
- Microbial contamination
- Starch content
Correct Answer: Amount of active constituents extractable with alcohol
Q9. Water-soluble extractive value is important because it indicates:
- Yield of polar constituents extractable with water
- Concentration of volatile oils
- Acid-insoluble ash content
- Heavy metal burden
Correct Answer: Yield of polar constituents extractable with water
Q10. Determination of foreign organic matter in crude drugs is normally performed by which method?
- Macroscopic separation and weighing of foreign matter
- HPLC quantification
- DNA sequencing of all particles
- Measuring total ash only
Correct Answer: Macroscopic separation and weighing of foreign matter
Q11. Which stationary phase is most commonly used for TLC of herbal extracts?
- Silica gel
- Polystyrene
- Cellulose acetate only
- Polyethylene
Correct Answer: Silica gel
Q12. A universal visualizing reagent for many plant constituents on TLC plates is:
- Anisaldehyde-sulfuric acid
- Ninhydrin only
- Silver nitrate solution
- Biuret reagent
Correct Answer: Anisaldehyde-sulfuric acid
Q13. Which reagent is commonly used to detect alkaloids in preliminary phytochemical tests?
- Dragendorff’s reagent
- Ferric chloride solution
- Molisch reagent
- Lead acetate
Correct Answer: Dragendorff’s reagent
Q14. Ferric chloride (FeCl3) test is mainly used to identify which class of phytochemicals?
- Phenolic compounds
- Saponins
- Alkaloids
- Proteins
Correct Answer: Phenolic compounds
Q15. Which simple test indicates the presence of saponins in a plant extract?
- Foam test (persistent frothing)
- Blue color with iodine
- Red precipitate with FeCl3
- Green color with Liebermann-Burchard
Correct Answer: Foam test (persistent frothing)
Q16. The Shinoda test is a phytochemical test used to detect which group?
- Flavonoids
- Cardiac glycosides
- Sterols
- Proteins
Correct Answer: Flavonoids
Q17. Bornträger’s test is used to detect which class of compounds in crude plant drugs?
- Anthraquinones
- Alkaloids
- Saponins
- Terpenes
Correct Answer: Anthraquinones
Q18. The Liebermann–Burchard reaction is a classical qualitative test for which constituents?
- Steroids and triterpenoids
- Alkaloids
- Carbohydrates
- Proteins
Correct Answer: Steroids and triterpenoids
Q19. Keller–Kiliani test is specifically used to indicate presence of which type of glycosides?
- Cardiac glycosides (cardenolides)
- Anthraquinone glycosides
- Flavonoid glycosides
- Saponin glycosides
Correct Answer: Cardiac glycosides (cardenolides)
Q20. Which reagent gives a blue-black color with starch in plant materials?
- Iodine-potassium iodide (I2/KI) solution
- Ferric chloride solution
- Dragendorff’s reagent
- Bornträger’s reagent
Correct Answer: Iodine-potassium iodide (I2/KI) solution
Q21. Calcium oxalate crystals such as raphides are best identified by which technique?
- Microscopic examination of powdered material
- Measuring pH
- Total ash estimation
- HPLC analysis
Correct Answer: Microscopic examination of powdered material
Q22. Why is controlling moisture content crucial in medicinal plant storage?
- To prevent microbial growth and chemical degradation
- To increase total ash values
- To enhance alkaloid production post-harvest
- To change plant taxonomy
Correct Answer: To prevent microbial growth and chemical degradation
Q23. Which physicochemical parameter helps estimate the quantity of constituents extractable by a given solvent?
- Extractive value
- Acid-insoluble ash
- Loss on drying
- Total ash
Correct Answer: Extractive value
Q24. If a sample shows a high acid-insoluble ash value, what is the most likely problem?
- Excess siliceous contamination (sand or soil)
- High volatile oil content
- Excessive sugars
- Low moisture content
Correct Answer: Excess siliceous contamination (sand or soil)
Q25. Which analytical technique is commonly employed for quantitative determination of heavy metals in plant materials?
- Atomic absorption spectroscopy (AAS)
- Thin layer chromatography (TLC)
- Foam test
- Shinoda test
Correct Answer: Atomic absorption spectroscopy (AAS)
Q26. Detection of adulteration in herbal drugs is best achieved by which combination?
- Macroscopic, microscopic and chemical tests
- Only organoleptic tests
- Only ash value determination
- Only DNA barcoding
Correct Answer: Macroscopic, microscopic and chemical tests
Q27. TLC plates observed under UV light at 254/366 nm primarily help to:
- Detect fluorescent or UV-absorbing compounds
- Measure moisture content
- Determine total ash
- Quantify microbial load
Correct Answer: Detect fluorescent or UV-absorbing compounds
Q28. Powdered drug microscopy is particularly useful for:
- Identifying diagnostic fragments such as fibers, vessels and crystals
- Measuring extractive values
- Determining heavy metal content
- Assessing pharmacological activity
Correct Answer: Identifying diagnostic fragments such as fibers, vessels and crystals
Q29. Which extraction technique uses continuous hot extraction to exhaustively extract a sample?
- Soxhlet extraction
- Maceration at room temperature
- Cold percolation only
- Foam test extraction
Correct Answer: Soxhlet extraction
Q30. Compared with classical TLC, HPTLC offers which major advantage in herbal analysis?
- Higher resolution, sensitivity and reproducibility
- Lower cost and no equipment required
- Eliminates the need for sample preparation
- Automatically identifies chemical structures
Correct Answer: Higher resolution, sensitivity and reproducibility
