Qualification of GC MCQs With Answer

Qualification of GC MCQs With Answer

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Qualification of GC MCQs With Answer

Introduction: This quiz collection on Qualification of Gas Chromatography (GC) is tailored for M.Pharm students preparing for advanced pharmaceutical validation topics. It focuses on the principles and practical aspects of qualifying a GC system — covering Installation Qualification (IQ), Operational Qualification (OQ), and Performance Qualification (PQ), system suitability, detector and column checks, calibration, and critical acceptance criteria. Questions emphasize regulatory expectations, data integrity, analytical performance characteristics (sensitivity, precision, linearity, specificity), and troubleshooting. Use these MCQs to deepen conceptual understanding and to prepare for exams or lab-based validation assignments where rigorous qualification documentation and interpretation are essential.

Q1. Which activity is typically performed during Installation Qualification (IQ) of a gas chromatograph?

  • Verifying system performance using certified reference standards
  • Documenting manufacturer, model, serial number, and utilities connections
  • Assessing method precision and accuracy with multiple replicates
  • Establishing long-term system suitability acceptance criteria

Correct Answer: Documenting manufacturer, model, serial number, and utilities connections

Q2. Operational Qualification (OQ) for a GC system most directly evaluates which of the following?

  • Long-term method robustness over months
  • Performance of individual components across operating ranges
  • Qualification of laboratory personnel
  • Regulatory submission dossier completeness

Correct Answer: Performance of individual components across operating ranges

Q3. Which test is an essential element of Performance Qualification (PQ) for an established GC method?

  • Verifying vendor installation checklist items
  • Demonstrating acceptable system suitability results on actual product samples
  • Confirming method development parameters such as initial gradient
  • Calibrating the mass flow controller with certified gases

Correct Answer: Demonstrating acceptable system suitability results on actual product samples

Q4. System suitability criteria for a GC assay commonly include all EXCEPT:

  • Theoretical plate count (efficiency)
  • Resolution between critical peaks
  • Tailoring factor or tailing factor
  • System health based solely on instrument serial number

Correct Answer: System health based solely on instrument serial number

Q5. During OQ, which parameter would you vary to demonstrate detector linearity for a flame ionization detector (FID)?

  • Injection volume only
  • Detector temperature exclusively
  • Concentration of analyte standards across intended range
  • Carrier gas type from helium to nitrogen

Correct Answer: Concentration of analyte standards across intended range

Q6. Which of these is the best acceptance criterion for chromatographic resolution between two active impurity peaks?

  • Resolution > 1.0 for any pair of peaks
  • Resolution > 2.0 for the pair of critical peaks
  • Resolution exactly equal to 1.5 for method transfer
  • Resolution does not need specification if retention times are consistent

Correct Answer: Resolution > 2.0 for the pair of critical peaks

Q7. Which documentation is most important to retain as evidence of GC qualification?

  • Only the instrument purchase receipt
  • IQ/OQ/PQ protocols and completed reports with raw data and signatures
  • Informal email confirmations from the vendor
  • Copies of unrelated method development notes

Correct Answer: IQ/OQ/PQ protocols and completed reports with raw data and signatures

Q8. What is the primary purpose of a system suitability test performed immediately before sample analysis?

  • To validate a new analytical method
  • To confirm the GC system is fit for the intended run and method
  • To train users on instrument operation
  • To check the instrument’s serial number

Correct Answer: To confirm the GC system is fit for the intended run and method

Q9. Which parameter best indicates column health and packing integrity during qualification?

  • Peak tailing factor and theoretical plates
  • Instrument network connectivity
  • Operator training certificates
  • Calibration certificate of glassware

Correct Answer: Peak tailing factor and theoretical plates

Q10. For detector noise assessment in GC, what measurement is typically used?

  • Signal-to-noise ratio measured from a blank baseline
  • Retention time reproducibility of a standard
  • Carrier gas pressure only
  • Injector septum color

Correct Answer: Signal-to-noise ratio measured from a blank baseline

Q11. Which action is part of routine GC qualification maintenance to ensure performance?

  • Ignoring recommended gas purity
  • Periodic leak checks and replacement of inlet seals and septa as needed
  • Never changing the column once installed
  • Using unfiltered environmental air for purging

Correct Answer: Periodic leak checks and replacement of inlet seals and septa as needed

Q12. In GC qualification, why is temperature program verification important?

  • Because column temperature does not affect retention
  • Because oven temperature profile influences retention time, resolution and method reproducibility
  • Temperature is irrelevant for FID detectors
  • Only inlet temperature matters, not oven profile

Correct Answer: Because oven temperature profile influences retention time, resolution and method reproducibility

Q13. Which parameter is commonly validated during OQ for the autosampler?

  • Autosampler injection precision and carryover
  • Color of the autosampler tray
  • Time taken to open the instrument manual
  • Vendor support response time

Correct Answer: Autosampler injection precision and carryover

Q14. How is limit of detection (LOD) in GC usually estimated during qualification?

  • By subjective observation of peaks
  • Using signal-to-noise ratio methods or calibration curve approaches
  • From the instrument serial number
  • By measuring retention time only

Correct Answer: Using signal-to-noise ratio methods or calibration curve approaches

Q15. When qualifying MS detectors coupled to GC (GC-MS), which additional check is essential compared to GC-FID?

  • Checking only carrier gas flow
  • Mass axis calibration and mass accuracy checks using reference compounds
  • Ensuring the autosampler tray lights are working
  • Verifying manufacturer brochures

Correct Answer: Mass axis calibration and mass accuracy checks using reference compounds

Q16. Which statement correctly distinguishes system suitability from method validation?

  • System suitability is identical to full method validation
  • System suitability is a routine check to ensure the system is performing per validated method criteria; method validation establishes method performance characteristics
  • Method validation is only for stability studies and not related to suitability
  • System suitability is only required once during instrument purchase

Correct Answer: System suitability is a routine check to ensure the system is performing per validated method criteria; method validation establishes method performance characteristics

Q17. Which gas quality issue can most directly affect peak shape and detector response in GC?

  • Low-purity carrier gas containing oxygen or moisture
  • Using glass syringes for injection
  • Ambient room lighting
  • Presence of magnets near the instrument

Correct Answer: Low-purity carrier gas containing oxygen or moisture

Q18. During PQ, which type of sample should be analyzed to demonstrate real-world performance?

  • Method development impurities only
  • Representative production or formulated samples with known impurities/actives
  • Only blank solvent
  • Manufacturer’s promotional samples

Correct Answer: Representative production or formulated samples with known impurities/actives

Q19. What is the recommended approach if system suitability fails during routine QC runs?

  • Proceed with sample analysis and report results
  • Investigate cause, rectify (e.g., maintenance, re-calibration), re-run suitability and affected samples
  • Ignore and change acceptance criteria to fit observed data
  • Replace chromatogram with a previous passing run

Correct Answer: Investigate cause, rectify (e.g., maintenance, re-calibration), re-run suitability and affected samples

Q20. Which metric is most appropriate to assess method precision during GC PQ?

  • Relative standard deviation (RSD) of replicate injections of a standard or sample
  • Absolute difference of serial numbers of instruments
  • Retention time of a single injection only
  • Number of pages in the SOP

Correct Answer: Relative standard deviation (RSD) of replicate injections of a standard or sample

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