Qualification of HPTLC MCQs With Answer

Qualification of HPTLC MCQs With Answer

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Introduction:

This blog on Qualification of HPTLC MCQs With Answer is tailored for M.Pharm students preparing for examinations and practical applications in pharmaceutical analysis. It focuses on qualification principles specific to High‑Performance Thin‑Layer Chromatography (HPTLC) including instrument, method and system qualifications (IQ/OQ/PQ), system suitability parameters, detection and densitometric considerations, method validation characteristics and common troubleshooting. Each question probes deeper into theoretical concepts, acceptance criteria, practical procedures and regulatory expectations to strengthen both conceptual understanding and laboratory readiness. Use these MCQs to evaluate knowledge, identify gaps and reinforce best practices for qualification and validation of HPTLC methods in a regulated environment.

Q1. Which document defines the formal acceptance criteria and tests to demonstrate that an HPTLC instrument is installed correctly and functions according to manufacturer specifications?

  • Operational Qualification (OQ)
  • Installation Qualification (IQ)
  • Performance Qualification (PQ)
  • System Suitability Report

Correct Answer: Installation Qualification (IQ)

Q2. During Performance Qualification (PQ) of an HPTLC method, which parameter is most appropriate to assess reproducibility under routine laboratory conditions?

  • Linearity of calibration curve over wide concentration range
  • Intermediate precision assessed as %RSD of replicate sample analyses on different days/operators
  • Limit of detection calculated from baseline noise
  • Plate storage condition validation

Correct Answer: Intermediate precision assessed as %RSD of replicate sample analyses on different days/operators

Q3. Which system suitability criterion specifically reflects peak symmetry in densitometric scanning of HPTLC spots or bands?

  • Theoretical plates (N)
  • Tailing factor (T)
  • Retention factor (Rf)
  • Resolution (Rs)

Correct Answer: Tailing factor (T)

Q4. For qualification of an HPTLC scanner detector, which test most directly evaluates wavelength accuracy?

  • Measurement of slit dimension using a micrometer
  • Calibration with certified holmium or didymium filter standards
  • Baseline noise assessment at a single wavelength
  • Checking lamp warm‑up time

Correct Answer: Calibration with certified holmium or didymium filter standards

Q5. During method validation on HPTLC, which experiment best demonstrates method specificity/selectivity?

  • Analyzing several concentrations to establish linearity
  • Comparing sample chromatogram with placebo and degradation products to ensure no co‑eluting peaks
  • Measuring LOD/LOQ by signal‑to‑noise approach
  • Assessing accuracy by recovery at three levels

Correct Answer: Comparing sample chromatogram with placebo and degradation products to ensure no co‑eluting peaks

Q6. Which parameter is most sensitive to changes in the width of applied bands during HPTLC qualification?

  • Retention factor (Rf)
  • Resolution between adjacent bands
  • Detector wavelength accuracy
  • Mobile phase saturation time

Correct Answer: Resolution between adjacent bands

Q7. In an HPTLC system suitability test, a resolution (Rs) of 0.9 is observed between two critical components. What is the typical regulatory expectation for Rs to claim adequate separation?

  • Rs ≥ 0.5
  • Rs ≥ 1.0
  • Rs ≥ 1.5
  • Rs ≥ 2.0

Correct Answer: Rs ≥ 1.5

Q8. Which of the following best describes the purpose of plate activation/conditioning before HPTLC development during qualification?

  • To remove residual mobile phase from the plate surface after development
  • To improve reproducibility by removing moisture and stabilizing sorbent activity
  • To calibrate the densitometer baseline
  • To increase the width of sample bands for better detection

Correct Answer: To improve reproducibility by removing moisture and stabilizing sorbent activity

Q9. Which acceptance criterion would you set for percent relative standard deviation (%RSD) of replicate peak area measurements during OQ of an HPTLC scanner?

  • %RSD ≤ 20%
  • %RSD ≤ 10%
  • %RSD ≤ 2–5%
  • %RSD ≤ 0.1%

Correct Answer: %RSD ≤ 2–5%

Q10. When calculating LOD and LOQ for an HPTLC method using signal‑to‑noise, which signal‑to‑noise ratios are conventionally used for LOD and LOQ respectively?

  • LOD: 1, LOQ: 3
  • LOD: 3, LOQ: 10
  • LOD: 10, LOQ: 30
  • LOD: 2, LOQ: 5

Correct Answer: LOD: 3, LOQ: 10

Q11. During OQ of the automated sample applicator, a critical parameter is uniformity of volume dispensed. Which technique is commonly used to qualify volume precision?

  • Weighing solvent dispensed onto the plate with a microbalance for multiple dispenses
  • Measuring band width on developed plate with a ruler
  • Assessing Rf shift of standard spots only
  • Recording lamp intensity over time

Correct Answer: Weighing solvent dispensed onto the plate with a microbalance for multiple dispenses

Q12. Which of the following is a direct indicator of chromatographic efficiency on an HPTLC plate?

  • Retention factor (Rf)
  • Theoretical plates per meter (N)
  • Spot color after derivatization
  • Chamber saturation time

Correct Answer: Theoretical plates per meter (N)

Q13. A validated HPTLC method shows significant peak area decrease after 24 hours at room temperature for prepared sample solutions. Which qualification/validation attribute is concerned and what action is required?

  • Specificity — reoptimize mobile phase
  • Solution stability — define and control sample storage conditions and acceptance holding time
  • Robustness — change plate brand
  • Linearity — extend calibration range

Correct Answer: Solution stability — define and control sample storage conditions and acceptance holding time

Q14. Which robustness test for an HPTLC method would reveal sensitivity to small changes in mobile phase composition?

  • Varying lamp warm‑up time by 10 minutes
  • Altering mobile phase ratio by ±1–2% and observing Rf and resolution changes
  • Changing plate manufacturer brand only
  • Varying plate activation temperature by 50°C

Correct Answer: Altering mobile phase ratio by ±1–2% and observing Rf and resolution changes

Q15. For quantitation in HPTLC, which calibration approach is most appropriate when sample matrix causes signal suppression or enhancement?

  • External standard calibration using solvent standards only
  • Standard addition method where known analyte amounts are spiked into the sample matrix
  • Using a single point calibrator at mid‑range concentration
  • Normalizing peak area to plate background

Correct Answer: Standard addition method where known analyte amounts are spiked into the sample matrix

Q16. During qualification, a repeatability study yields an Rf variation of ±0.08 for a compound with nominal Rf 0.73. Is this acceptable and what is the likely cause?

  • Acceptable — variation is typical for HPTLC; cause: detector drift
  • Not acceptable — wide Rf variation likely due to inconsistent chamber saturation, plate conditioning, or mobile phase composition
  • Acceptable — caused by sample concentration differences only
  • Not acceptable — caused by improper densitometer wavelength selection

Correct Answer: Not acceptable — wide Rf variation likely due to inconsistent chamber saturation, plate conditioning, or mobile phase composition

Q17. Which documentation is essential to retain after completing IQ/OQ/PQ of an HPTLC system per regulatory expectations?

  • Only the final summary report
  • Complete qualification protocols, raw data, deviation reports, corrective actions and approved summary report
  • Only calibration certificates for the balance and pipettes used
  • Vendor brochure and instruction manual only

Correct Answer: Complete qualification protocols, raw data, deviation reports, corrective actions and approved summary report

Q18. In HPTLC densitometry, which slit dimension adjustment predominantly affects peak resolution versus sensitivity?

  • Wavelength increment in the scanner
  • Slit height — smaller height increases resolution across the band but may reduce signal
  • Spray derivatizer flow rate
  • Integration baseline smoothing parameter

Correct Answer: Slit height — smaller height increases resolution across the band but may reduce signal

Q19. Which performance qualification test would best demonstrate the ruggedness of an HPTLC method when performed in two different laboratories?

  • Assessing same‑day repeatability in a single lab
  • Comparing accuracy and precision (%recovery and %RSD) of sample analysis across the two labs with different analysts and instruments
  • Measuring detector noise only in both labs
  • Comparing brand of mobile phase solvents used

Correct Answer: Comparing accuracy and precision (%recovery and %RSD) of sample analysis across the two labs with different analysts and instruments

Q20. When qualifying derivatization procedures for HPTLC detection (e.g., for non‑UV active compounds), which attribute must be demonstrated?

  • That derivatization is reversible under standard development conditions
  • Specificity, reproducibility of color/fluorescence response, stability of derivative and linearity of detector response after derivatization
  • That derivatization increases Rf values uniformly
  • That derivatization eliminates need for mobile phase optimization

Correct Answer: Specificity, reproducibility of color/fluorescence response, stability of derivative and linearity of detector response after derivatization

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