Qualification of UV-Visible spectrophotometer MCQs With Answer is an essential topic for B. Pharm students preparing for laboratory validation and regulatory compliance. This introduction covers core concepts such as IQ, OQ, PQ, wavelength accuracy, photometric accuracy, spectral bandwidth, stray light, linearity, precision, and calibration standards like holmium oxide and neutral density filters. You will also learn about lamp types (deuterium, tungsten), detector technologies, USP <857> requirements, and practical tests used during qualification. The questions below are aimed to deepen your understanding of instrument performance, troubleshooting, and acceptance criteria vital for pharmaceutical analysis. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which standard is commonly used for wavelength accuracy qualification of a UV-Visible spectrophotometer?
- Potassium dichromate solution
- Neutral density filter
- Holmium oxide filter
- Sodium chloride solution
Correct Answer: Holmium oxide filter
Q2. Which light source is typically used for measurements in the ultraviolet (UV) region?
- Tungsten-halogen lamp
- Deuterium lamp
- LED lamp
- Mercury-vapor lamp
Correct Answer: Deuterium lamp
Q3. What does IQ stand for in instrument qualification?
- Instrument Quality
- Installation Qualification
- Initial Qualification
- Internal Qualification
Correct Answer: Installation Qualification
Q4. Which test evaluates the instrument’s ability to produce correct absorbance values at known transmittance levels?
- Wavelength accuracy
- Photometric accuracy
- Stray light test
- Resolution test
Correct Answer: Photometric accuracy
Q5. What does OQ verify during spectrophotometer qualification?
- Instrument is installed correctly
- Operational performance meets specifications
- Daily calibration procedures
- Regulatory approvals are obtained
Correct Answer: Operational performance meets specifications
Q6. Which parameter describes the width of light that passes through the monochromator, affecting spectral detail?
- Spectral bandwidth
- Photometric range
- Baseline drift
- Wavelength repeatability
Correct Answer: Spectral bandwidth
Q7. Which component converts light into an electrical signal in most UV-Visible spectrophotometers?
- Monochromator slit
- Sample cuvette
- Detector (e.g., photodiode or PMT)
- Reference lamp
Correct Answer: Detector (e.g., photodiode or PMT)
Q8. What is the primary purpose of PQ (Performance Qualification)?
- Confirm installation is complete
- Document vendor specifications
- Demonstrate instrument performs reliably under routine use
- Train users on software only
Correct Answer: Demonstrate instrument performs reliably under routine use
Q9. Which substance is often used as a photometric/linearity standard in UV calibration protocols?
- Holmium oxide
- Neutral density filters
- Deionized water
- Hydrochloric acid
Correct Answer: Neutral density filters
Q10. What is stray light in the context of UV-Visible spectrophotometry?
- Light absorbed by the sample only
- Light from the source at the nominal wavelength
- Unwanted light reaching the detector outside the selected wavelength
- Light reflected from cuvette surfaces only
Correct Answer: Unwanted light reaching the detector outside the selected wavelength
Q11. Which USP chapter specifically addresses UV-Visible spectrophotometry expectations for pharmaceutical analysis?
- USP <621>
- USP <857>
- USP <1120>
- USP <1010>
Correct Answer: USP <857>
Q12. Beer–Lambert law relates absorbance to which factors?
- Wavelength and slit width
- Path length and concentration
- Lamp intensity and detector type
- Baseline drift and noise
Correct Answer: Path length and concentration
Q13. Which test assesses the instrument’s ability to resolve two closely spaced spectral peaks?
- Photometric linearity
- Resolution test
- Wavelength repeatability
- Stray light assessment
Correct Answer: Resolution test
Q14. Which lamp is commonly used for visible region measurements in UV-Vis spectrophotometers?
- Deuterium lamp
- Tungsten-halogen lamp
- Laser diode
- Mercury vapor lamp
Correct Answer: Tungsten-halogen lamp
Q15. What does wavelength repeatability refer to?
- Ability to maintain a stable baseline over time
- Ability to return to a set wavelength reliably on repeated selections
- Ability to measure very high absorbance values
- Ability to filter stray light
Correct Answer: Ability to return to a set wavelength reliably on repeated selections
Q16. Which acceptance feature indicates adequate baseline stability?
- High spectral bandwidth
- Low baseline noise and drift
- High stray light
- Large wavelength shift
Correct Answer: Low baseline noise and drift
Q17. During qualification, traceability of standards means what?
- Standards are inexpensive
- Standards have documentation linking them to national/international references
- Standards are kept in the instrument case
- Standards are replaced weekly
Correct Answer: Standards have documentation linking them to national/international references
Q18. What effect does increasing the spectral bandwidth have on spectral resolution?
- Improves resolution (better separation)
- Reduces resolution (poorer separation)
- Has no effect on resolution
- Eliminates stray light completely
Correct Answer: Reduces resolution (poorer separation)
Q19. Which measurement is unitless and commonly reported directly by UV-Vis instruments?
- Wavelength in nm
- Absorbance (A)
- Stray light in lux
- Spectral bandwidth in Hz
Correct Answer: Absorbance (A)
Q20. What is an appropriate action if photometric linearity fails during OQ?
- Ignore and proceed to PQ
- Replace the sample cuvette only
- Investigate lamp, detector, slit alignment and recalibrate
- Reduce sample concentration without further checks
Correct Answer: Investigate lamp, detector, slit alignment and recalibrate
Q21. Which detector type provides rapid full-spectrum acquisition in modern UV-Vis instruments?
- Photomultiplier tube (PMT) only
- Charge-coupled device (CCD) or photodiode array (PDA)
- Mercury detector
- Thermocouple detector
Correct Answer: Charge-coupled device (CCD) or photodiode array (PDA)
Q22. What is usually the first step in instrument qualification?
- Performance Qualification (PQ)
- Operational Qualification (OQ)
- Installation Qualification (IQ)
- Routine calibration check
Correct Answer: Installation Qualification (IQ)
Q23. Which factor can cause increased baseline noise?
- Stable power supply
- Properly aligned optics
- Old or failing lamp
- Fresh calibration standards
Correct Answer: Old or failing lamp
Q24. For routine system suitability, which parameter is commonly monitored?
- Monthly software updates only
- Wavelength accuracy, photometric accuracy, and baseline noise
- User login times
- Storage cabinet humidity only
Correct Answer: Wavelength accuracy, photometric accuracy, and baseline noise
Q25. What is the practical linear absorbance range where Beer–Lambert law is most reliable?
- Above 3.0 absorbance units
- Approximately 0.0 to 1.0 absorbance units
- Only at 0.0001 absorbance
- Only at negative absorbance values
Correct Answer: Approximately 0.0 to 1.0 absorbance units
Q26. Which of the following is a good preventive maintenance task to extend lamp life?
- Operate lamp continuously at maximum intensity without breaks
- Allow warm-up time before measurements and replace lamps per vendor recommendations
- Submerge lamp in solvent to clean
- Open monochromator during operation to cool lamp
Correct Answer: Allow warm-up time before measurements and replace lamps per vendor recommendations
Q27. Which test would detect significant stray light affecting low-transmittance measurements?
- Wavelength repeatability test
- Stray light test using a high-absorbance or cutoff filter
- Baseline noise check at zero absorbance only
- Colorimetric pH test
Correct Answer: Stray light test using a high-absorbance or cutoff filter
Q28. Why is documentation of qualification activities important in pharmaceutical labs?
- Only to increase paper usage
- To provide evidence of compliance, traceability, and reproducibility
- It is optional and rarely reviewed
- To avoid using standardized procedures
Correct Answer: To provide evidence of compliance, traceability, and reproducibility
Q29. Which practice ensures accurate wavelength calibration over time?
- Never checking standards after initial setup
- Regular verification with certified wavelength standards and recorded trend data
- Changing spectral bandwidth daily without documentation
- Relying only on software defaults with no checks
Correct Answer: Regular verification with certified wavelength standards and recorded trend data
Q30. During qualification, what documentation confirms that acceptance criteria were met for each test?
- Verbal confirmation only
- Qualification protocol and summary reports with signatures
- Random emails without attachments
- Unstamped handwritten notes without dates
Correct Answer: Qualification protocol and summary reports with signatures
I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.
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