Chemical tests for Asafoetida MCQs With Answer provide B.Pharm students a focused, practical guide to identifying and standardizing this important herbal gum-resin. Asafoetida (Ferula asafoetida) contains resin, gum, volatile oil and sulfur‑containing compounds; quality control uses organoleptic checks, solubility tests, ferric chloride reactions for phenolics, TLC/HPLC for marker compounds (e.g., ferulic acid), and GC‑MS for volatile fractions. Understanding ash values, loss on drying, and specific chemical spot tests helps detect adulteration and ensure pharmaceutical quality. This concise, keyword‑rich introduction links phytochemistry, analytical methods and pharmacognosy for exam readiness and laboratory application. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which are the primary chemical constituents of asafoetida relevant to pharmacognostic tests?
- Resin, gum, volatile oil and sulfur compounds
- Alkaloids, tannins, saponins and proteins
- Polysaccharides only
- Only essential fatty acids
Correct Answer: Resin, gum, volatile oil and sulfur compounds
Q2. What simple organoleptic test most reliably indicates authentic asafoetida?
- Sweet taste on the tongue
- Mild floral aroma on heating
- Strong sulphurous, alliaceous odour on rubbing or heating
- Blue fluorescence under UV light
Correct Answer: Strong sulphurous, alliaceous odour on rubbing or heating
Q3. Which solvent will preferentially extract the resin fraction from asafoetida?
- Cold water
- Ethanol or methanol
- Petroleum ether exclusively
- Dilute acetic acid
Correct Answer: Ethanol or methanol
Q4. Which test indicates the presence of gum in asafoetida?
- Solubility in petroleum ether with clear solution
- Swelling and formation of viscous mucilage in water
- Immediate precipitation on addition of ethanol
- Blue colour with ferric chloride
Correct Answer: Swelling and formation of viscous mucilage in water
Q5. The ferric chloride test on an alcoholic extract of asafoetida is primarily used to detect which class of compounds?
- Alkaloids
- Phenolic compounds such as ferulic acid
- Sugars
- Proteins
Correct Answer: Phenolic compounds such as ferulic acid
Q6. Which chromatographic technique is commonly used to separate and identify marker phenolic acids in asafoetida?
- Paper chromatography only
- TLC followed by densitometry or HPLC confirmation
- Gel electrophoresis
- Size exclusion chromatography for volatile oils
Correct Answer: TLC followed by densitometry or HPLC confirmation
Q7. For detailed profiling of volatile sulfur compounds in asafoetida, which analytical method is most appropriate?
- UV–Vis spectrophotometry
- Gas chromatography–mass spectrometry (GC–MS)
- Paper electrophoresis
- Flame photometry
Correct Answer: Gas chromatography–mass spectrometry (GC–MS)
Q8. Blackening of lead acetate paper when exposed to steam distilled vapors from asafoetida indicates presence of:
- Volatile sulfur compounds (sulfides/thiols)
- Alkaloids
- Carbohydrates
- Phenolic acids
Correct Answer: Volatile sulfur compounds (sulfides/thiols)
Q9. Which quality control parameter measures inorganic residue after complete burning of asafoetida sample?
- Loss on drying
- Total ash value
- Acid value
- Saponification value
Correct Answer: Total ash value
Q10. Loss on drying (LOD) for asafoetida is determined to assess:
- Volatile oil composition
- Moisture content and stability
- Phenolic content
- Resin purity
Correct Answer: Moisture content and stability
Q11. Which chemical test would you use to detect carbohydrate (gum) presence in an alcoholic extract of asafoetida?
- Molinspiration test
- Molisch’s test (formation of a violet ring)
- Dragendorff’s test
- Kjeldahl test
Correct Answer: Molisch’s test (formation of a violet ring)
Q12. Which reagent gives a characteristic colour change with phenolic acids like ferulic acid in a spot test?
- Ferric chloride producing green/blue or violet colours
- Sodium nitroprusside producing orange
- Dragendorff’s giving red precipitate
- Biuret reagent producing pink
Correct Answer: Ferric chloride producing green/blue or violet colours
Q13. Which analytical parameter is most useful to detect siliceous adulterants (e.g., sand) in asafoetida?
- Acid‑insoluble ash
- Water solubility index
- Optical rotation
- pH of aqueous extract
Correct Answer: Acid‑insoluble ash
Q14. A simple laboratory test to indicate resin presence involves:
- Extracting with ethanol and diluting with water to precipitate resin
- Adding iodine solution to see blue colour
- Heating with concentrated nitric acid to yield brown fumes
- Mixing with chloroform to obtain a clear aqueous layer
Correct Answer: Extracting with ethanol and diluting with water to precipitate resin
Q15. Which test is typically negative when performed on asafoetida because it is not a major starch source?
- Iodine test for starch (blue‑black colour)
- Molisch’s test for carbohydrates
- Ferric chloride for phenols
- Lead acetate paper test for sulfides
Correct Answer: Iodine test for starch (blue‑black colour)
Q16. Which chromatographic technique is preferred for quantification of a non‑volatile marker such as ferulic acid in asafoetida?
- Gas chromatography (GC)
- High‑performance liquid chromatography (HPLC)
- Paper chromatography for quantification
- Thin layer chromatography without densitometry
Correct Answer: High‑performance liquid chromatography (HPLC)
Q17. Shinoda test (metallic magnesium and HCl) in asafoetida screening is used to detect which class of phytochemicals?
- Flavonoids (reddish/pink colour on positive test)
- Alkaloids only
- Steroids and triterpenes exclusively
- Gums and mucilages
Correct Answer: Flavonoids (reddish/pink colour on positive test)
Q18. Which of the following is NOT primarily a chemical test used in asafoetida quality control?
- Total ash determination
- Gas chromatography of volatile oil
- Microbial limit test for pathogens
- Ferric chloride test for phenolics
Correct Answer: Microbial limit test for pathogens
Q19. A decrease in volatile oil content on storage is best monitored by which parameter?
- Change in total ash value
- Periodic GC‑MS analysis of oil composition
- Molisch’s carbohydrate test
- Acid‑insoluble ash
Correct Answer: Periodic GC‑MS analysis of oil composition
Q20. Which of the following standard tests helps detect addition of starch as an adulterant in asafoetida?
- Ferric chloride test
- Iodine test for starch (blue‑black colour)
- Lead acetate paper test
- TLC for ferulic acid
Correct Answer: Iodine test for starch (blue‑black colour)
Q21. Which value indicates the amount of free acidity in an oil or resin fraction of asafoetida?
- Moisture content
- Acid value
- Total ash
- Specific rotation
Correct Answer: Acid value
Q22. In a TLC of asafoetida alcoholic extract, visualization of spots under UV after spraying with anisaldehyde is mainly used to detect:
- Volatile sulfur gases directly
- Diverse resin and phenolic components as coloured spots
- Inorganic adulterants
- Microbial contamination
Correct Answer: Diverse resin and phenolic components as coloured spots
Q23. Which simple laboratory observation indicates presence of volatile oil in asafoetida during distillation?
- Formation of a persistent fragrant oil layer after steam distillation
- Complete disappearance of all solids
- Immediate blue coloration of distillate
- Foaming in cold water
Correct Answer: Formation of a persistent fragrant oil layer after steam distillation
Q24. Which of the following reagents is commonly used to reveal phenolic spots on TLC plates by producing coloured complexes?
- Ninhydrin
- Ferric chloride solution
- Dragendorff’s reagent
- Molisch reagent
Correct Answer: Ferric chloride solution
Q25. The presence of sulfide/thiol functional groups in asafoetida volatile oil can be indicated by which analytical reaction?
- Blue precipitate with Benedict’s reagent
- Blackening with lead acetate/lead nitrate due to metal sulfide formation
- Red precipitate with Wagner’s reagent
- Violet colour with ferric chloride
Correct Answer: Blackening with lead acetate/lead nitrate due to metal sulfide formation
Q26. Which pharmacological property is commonly attributed to asafoetida and relevant when considering its chemical constituents?
- Strong hypoglycemic activity due to alkaloids
- Carminative and antispasmodic effects related to volatile oils and resin
- Anticoagulant action due to fatty acids
- Primary antibiotic action due to proteins
Correct Answer: Carminative and antispasmodic effects related to volatile oils and resin
Q27. Which parameter is useful to assess hygroscopic deterioration of asafoetida during storage?
- Increase in total ash
- Increase in moisture content (loss on drying changes)
- Increase in ferulic acid concentration
- Decrease in acid‑insoluble ash only
Correct Answer: Increase in moisture content (loss on drying changes)
Q28. For standardization of asafoetida in a pharmacopeial monograph, which marker compound is often quantified?
- Ferulic acid (a phenolic acid)
- Nicotine
- Curcumin
- Caffeine
Correct Answer: Ferulic acid (a phenolic acid)
Q29. Which test would most directly reveal adulteration of asafoetida with cheap vegetable oil?
- Determination of volatile oil content and GC profiling
- Ferric chloride test for phenolics
- Molisch’s carbohydrate test
- Acid‑insoluble ash measurement
Correct Answer: Determination of volatile oil content and GC profiling
Q30. Which storage condition is recommended to preserve volatile oil and chemical integrity of asafoetida?
- Open container at room temperature in sunlight
- Airtight container in a cool, dark, dry place
- High humidity environment
- Near heat sources to keep it dry
Correct Answer: Airtight container in a cool, dark, dry place
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