Adulteration of drugs of natural origin MCQs With Answer is a focused set for B.Pharm students covering adulteration, contamination, substitution, and quality control of herbal and natural drugs. This introduction highlights key terms: adulteration, herbal drugs, pharmacognosy, authentication, analytical methods (TLC, HPTLC, HPLC, GC-MS, DNA barcoding), pharmacopoeial standards, contaminants (heavy metals, pesticides, microbes), and common adulterants (starches, dyes, cheaper plant species). The questions emphasize detection techniques, sampling, legal and safety implications, and real-world case studies to deepen understanding of screening and confirmatory tests. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which term best describes deliberate replacement of a valuable medicinal plant with a cheaper species?
- Contamination
- Substitution
- Adulteration by dilution
- Natural variation
Correct Answer: Substitution
Q2. Which simple organoleptic method helps detect adulteration in powdered herbal drugs?
- Thin layer chromatography
- Microscopy
- Color, odor, and taste examination
- DNA barcoding
Correct Answer: Color, odor, and taste examination
Q3. Which microscopic feature is commonly used to authenticate powdered plant drugs?
- Retention time in HPLC
- Presence of specific stomata, trichomes, or fibers
- UV absorbance at 254 nm
- Mass spectral fragmentation pattern
Correct Answer: Presence of specific stomata, trichomes, or fibers
Q4. Which chromatographic technique is most commonly used for fingerprinting and semi-quantitative analysis of herbal extracts in quality control?
- Gas chromatography with FID
- High performance thin layer chromatography (HPTLC)
- Capillary electrophoresis
- Paper chromatography
Correct Answer: High performance thin layer chromatography (HPTLC)
Q5. Which modern molecular method can detect species-level substitution in herbal drugs?
- Melting point determination
- DNA barcoding
- Infrared spectroscopy
- Loss on drying
Correct Answer: DNA barcoding
Q6. Which is a common adulterant added to powdered herbal drugs to increase bulk?
- Starch
- Gold nanoparticles
- Enzymes
- Recombinant proteins
Correct Answer: Starch
Q7. Presence of which contaminant is primarily assessed by atomic absorption spectroscopy or ICP methods?
- Microbial contamination
- Pesticide residues
- Heavy metals (lead, arsenic, cadmium)
- Residual solvents
Correct Answer: Heavy metals (lead, arsenic, cadmium)
Q8. Which analytical technique provides both qualitative and quantitative confirmation of volatile adulterants and pesticides?
- HPTLC
- GC-MS
- Polarimetry
- Karl Fischer titration
Correct Answer: GC-MS
Q9. Which test is NOT typically used for preliminary screening of cardiac glycosides in plant materials?
- Kedde test
- Baljet test
- Trease and Evans test for tannins
- Liebermann-Burchard test for steroids
Correct Answer: Trease and Evans test for tannins
Q10. Which pharmacopoeial parameter directly detects foreign inorganic materials in crude drugs?
- Assay for active principle
- Loss on drying
- Total ash and acid-insoluble ash
- Thin layer chromatographic profile
Correct Answer: Total ash and acid-insoluble ash
Q11. HPTLC offers which main advantage over conventional TLC for herbal drug analysis?
- Lower sensitivity
- Less reproducibility
- Higher resolution and densitometric quantification
- Inability to use automated application
Correct Answer: Higher resolution and densitometric quantification
Q12. Which contamination is a major concern in storage of herbal drugs and may be detected by mycotoxin assays?
- Heavy metal contamination
- Aflatoxin contamination from molds
- Pigment fading
- Residual solvent contamination
Correct Answer: Aflatoxin contamination from molds
Q13. What is the primary purpose of conducting assay and content uniformity tests on herbal extracts?
- To determine microbial limits only
- To quantify active constituents and ensure dosage consistency
- To identify foreign species by microscopy
- To check for inorganic ash content only
Correct Answer: To quantify active constituents and ensure dosage consistency
Q14. Which practice reduces risk of accidental contamination during collection and processing of medicinal plants?
- Mixing batches from different sources
- Good Agricultural and Collection Practices (GACP)
- Storing in open, humid conditions
- Using uncalibrated grinders
Correct Answer: Good Agricultural and Collection Practices (GACP)
Q15. Which regulatory document provides monographs and official tests for herbal drugs used in many countries?
- Vehicle maintenance manual
- Pharmacopoeia (e.g., IP, BP, USP)
- Food recipe book
- Industrial safety datasheet
Correct Answer: Pharmacopoeia (e.g., IP, BP, USP)
Q16. In TLC fingerprinting, what indicates possible adulteration when comparing sample and reference?
- Identical Rf values and color of spots
- Missing characteristic spots or extra unexpected spots
- Same solvent front distance only
- Use of a glass plate instead of aluminum
Correct Answer: Missing characteristic spots or extra unexpected spots
Q17. Which parameter is assessed to evaluate microbial safety of herbal formulations?
- Total viable count and specific pathogens (e.g., E. coli, Salmonella)
- Acid-insoluble ash only
- Sugar content only
- Melting point of constituents
Correct Answer: Total viable count and specific pathogens (e.g., E. coli, Salmonella)
Q18. Which is a typical indicator of intentional chemical adulteration in herbal preparations marketed for diabetes?
- Presence of plant fibers
- Detection of undeclared synthetic hypoglycemic drugs
- Reduced moisture content
- Higher ash value
Correct Answer: Detection of undeclared synthetic hypoglycemic drugs
Q19. What is the role of marker compounds in herbal drug standardization?
- They serve no analytical purpose
- Indicator for identification and quantification of quality
- They replace the need for any chromatographic tests
- They are only used in botanical nomenclature
Correct Answer: Indicator for identification and quantification of quality
Q20. Which sample preparation technique is commonly used before chromatographic analysis of herbal extracts?
- Direct injection of crude powder without extraction
- Solvent extraction followed by filtration and concentration
- Combustion of sample
- Lyophilization of whole plant without solvent
Correct Answer: Solvent extraction followed by filtration and concentration
Q21. Which statement about economic adulteration is correct?
- It is always accidental and due to environmental factors
- It is deliberate addition or substitution to increase profit
- It refers only to pesticide contamination
- It cannot be detected by chromatographic methods
Correct Answer: It is deliberate addition or substitution to increase profit
Q22. Which test is most appropriate for detecting undeclared synthetic analgesics in herbal pain relief products?
- Microscopy for stomata
- HPLC or LC-MS screening for synthetic drugs
- Total ash determination
- Organoleptic taste test
Correct Answer: HPLC or LC-MS screening for synthetic drugs
Q23. Which contamination might result from improper drying and storage of herbal materials?
- Increase in active principle content
- Microbial growth and mycotoxin formation
- Guaranteed pharmacopoeial compliance
- Enhanced DNA stability
Correct Answer: Microbial growth and mycotoxin formation
Q24. For authentication of powdered roots where microscopy is inconclusive, which method gives species-specific confirmation?
- Color comparison with reference powder
- DNA-based methods such as PCR or barcoding
- Determination of moisture content only
- Measuring pH of extract
Correct Answer: DNA-based methods such as PCR or barcoding
Q25. Which is an example of unintentional adulteration of herbal drugs?
- Adulteration with cheaper plant species by suppliers
- Cross-contamination with weeds during harvesting
- Deliberate addition of synthetic steroids
- Labeling with false potency claims
Correct Answer: Cross-contamination with weeds during harvesting
Q26. Which parameter is critical for detecting inorganic contaminants introduced during processing?
- HPTLC fingerprint
- Total ash and heavy metal analysis
- UV spectra only
- Organoleptic evaluation
Correct Answer: Total ash and heavy metal analysis
Q27. Which of the following is a limitation of relying solely on organoleptic and microscopic tests?
- They are always sufficient for full authentication
- They cannot detect chemical adulterants or synthetic drugs reliably
- They detect DNA-level substitution reliably
- They quantify active constituents accurately
Correct Answer: They cannot detect chemical adulterants or synthetic drugs reliably
Q28. Which proactive measure helps prevent economic adulteration in supply chains?
- Purchasing from unknown suppliers
- Implementing established supplier qualification and traceability
- Mixing lots without testing
- Ignoring pharmacopoeial standards
Correct Answer: Implementing established supplier qualification and traceability
Q29. Which analytical workflow is appropriate for confirmation when an HPTLC fingerprint shows an unexpected spot?
- Ignore the spot and release the batch
- Isolate the spot and analyze by LC-MS or GC-MS for identification
- Only measure moisture content
- Perform organoleptic test alone
Correct Answer: Isolate the spot and analyze by LC-MS or GC-MS for identification
Q30. Which principle underlies the use of pharmacopoeial monographs to control adulteration of natural drugs?
- Providing standardized identity, purity, and assay tests to ensure quality and safety
- Encouraging uncontrolled variability in raw materials
- Mandating only organoleptic tests without chemical assays
- Promoting intentional substitution to reduce costs
Correct Answer: Providing standardized identity, purity, and assay tests to ensure quality and safety
