Applications of flame emission spectroscopy MCQs With Answer

Applications of flame emission spectroscopy MCQs With Answer

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Applications of flame emission spectroscopy MCQs With Answer is designed to help M.Pharm students master how flame emission spectroscopy (FES) is applied across pharmaceutical analysis and clinical chemistry. This quiz emphasizes real-world uses such as quantifying alkali and alkaline earth metals in formulations, parenterals, dialysate, glass leachables, and biological fluids. You will also encounter questions on method optimization, matrix handling, interference control, and appropriate calibration strategies that ensure accuracy and robustness in routine QC. By working through these MCQs, you will refine your understanding of when and why FES is preferred, its limitations compared with other spectrometric techniques, and best practices for sample preparation and validation in modern pharmaceutical analytical techniques.

Q1. Which analytes are best suited to routine pharmaceutical analysis by flame emission spectroscopy (FES)?

  • Sodium, potassium, lithium, and calcium in pharmaceutical samples
  • Trace mercury, lead, and cadmium at ppb levels
  • Aromatic impurity profiling in active pharmaceutical ingredients
  • Halogen content in propellants by combustion ion chromatography

Correct Answer: Sodium, potassium, lithium, and calcium in pharmaceutical samples

Q2. In QC of large-volume parenterals (LVPs) and infusion fluids, FES is routinely applied to verify label claims for which components?

  • Sodium and potassium chloride content
  • Dextrose concentration
  • Amino acid profile
  • Benzyl alcohol preservative level

Correct Answer: Sodium and potassium chloride content

Q3. Which internal standard is commonly added to correct aspiration and flame fluctuations when measuring serum sodium and potassium by FES?

  • Lithium
  • Calcium
  • Magnesium
  • Iron

Correct Answer: Lithium

Q4. To minimize phosphate interference when determining calcium by FES, analysts often add:

  • Lanthanum chloride
  • Sodium chloride
  • Ammonium carbonate
  • Glucose

Correct Answer: Lanthanum chloride

Q5. Which flame combination is most commonly used in simple flame photometers for routine Na and K measurements in pharmaceutical solutions?

  • Air–LPG (air–propane) flame
  • Nitrous oxide–acetylene flame
  • Hydrogen–oxygen flame
  • Argon plasma

Correct Answer: Air–LPG (air–propane) flame

Q6. The principal emission line monitored for lithium in pharmaceutical assays by FES is approximately:

  • 670.8 nm
  • 589.0 nm
  • 766.5 nm
  • 422.7 nm

Correct Answer: 670.8 nm

Q7. For determining trace lead contamination in a finished dosage form, the more appropriate technique than FES is:

  • Atomic absorption spectroscopy (AAS)
  • Thin-layer chromatography (TLC)
  • Infrared spectroscopy (IR)
  • Polarimetry

Correct Answer: Atomic absorption spectroscopy (AAS)

Q8. Before measuring serum electrolytes by FES, deproteinization is commonly performed using:

  • Trichloroacetic acid (TCA)
  • Sodium hydroxide
  • Glycerol
  • Potassium permanganate

Correct Answer: Trichloroacetic acid (TCA)

Q9. Which calibration strategy best compensates for matrix effects in complex pharmaceutical or biological samples analyzed by FES?

  • Standard addition method
  • External calibration with water standards only
  • One-point calibration at mid-range
  • Normalization by sample mass alone

Correct Answer: Standard addition method

Q10. FES can be applied to monitor water hardness relevant to pharmaceutical utilities primarily by quantifying:

  • Calcium ions
  • Iron ions
  • Zinc ions
  • Aluminum ions

Correct Answer: Calcium ions

Q11. To suppress ionization of alkali metals in hot flames during FES, analysts add:

  • Cesium chloride as an ionization buffer
  • Sodium dodecyl sulfate as a surfactant
  • Ethylenediaminetetraacetic acid as a chelating agent
  • Sulfuric acid as an oxidant

Correct Answer: Cesium chloride as an ionization buffer

Q12. Why is FES preferred for routine monitoring of sodium and potassium in oral rehydration salts (ORS) during manufacturing?

  • Rapid, precise determination at ppm levels with minimal sample prep
  • Ability to detect organic degradants in the formulation
  • Superior selectivity for transition metals at ppb levels
  • Capability for direct analysis of undiluted solids without dissolution

Correct Answer: Rapid, precise determination at ppm levels with minimal sample prep

Q13. In therapeutic drug monitoring of lithium carbonate, FES is often applied to measure lithium in:

  • Serum
  • Exhaled breath condensate
  • Cerebrospinal fluid without pretreatment
  • Sweat patches

Correct Answer: Serum

Q14. The analytical emission line most commonly selected for potassium in FES is near:

  • 766.5 nm
  • 589.0 nm
  • 404.7 nm
  • 248.3 nm

Correct Answer: 766.5 nm

Q15. In evaluating the hydrolytic resistance of pharmaceutical glass containers, FES can be used to measure:

  • Sodium and potassium leached into the extraction solution
  • Silica network dissolution rate directly
  • Organic extractables from rubber stoppers
  • Barium sulfate particulate counts

Correct Answer: Sodium and potassium leached into the extraction solution

Q16. A key practical limitation that defines the application scope of basic flame photometers in pharmaceutical QC is:

  • Limited sensitivity for most transition metals at trace levels
  • Inability to measure sodium accurately
  • Requirement of vacuum systems and high-purity argon
  • Lack of linearity for alkali metals

Correct Answer: Limited sensitivity for most transition metals at trace levels

Q17. When determining sodium in a viscous syrup matrix by FES, the best approach to minimize nebulization bias is to use:

  • Matrix‑matched standards with similar sugar content and viscosity
  • Water-only standards with vigorous aspiration
  • Higher flame temperature alone
  • Ultrasonic agitation during aspiration only

Correct Answer: Matrix‑matched standards with similar sugar content and viscosity

Q18. In quality control of hemodialysis concentrates and dialysate, FES is commonly used to verify:

  • Sodium, potassium, and calcium concentrations
  • Iron and copper trace contaminants
  • Chloramine residuals
  • Phosphate buffer capacity

Correct Answer: Sodium, potassium, and calcium concentrations

Q19. Samples are often diluted before FES measurements primarily to:

  • Bring analyte concentrations into the linear response range and reduce matrix effects
  • Increase the flame temperature
  • Enhance spectral interferences
  • Remove dissolved gases

Correct Answer: Bring analyte concentrations into the linear response range and reduce matrix effects

Q20. In routine flame photometry, the simplest baseline correction for flame/background emission is to:

  • Zero the instrument with a reagent blank and subtract its signal
  • Use Zeeman background correction
  • Switch to ICP-OES mode
  • Apply first-derivative signal processing

Correct Answer: Zero the instrument with a reagent blank and subtract its signal

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