Question 1: Which analytical method is most effective for the non-destructive analysis of ink on historical documents?
- A. Paper chromatography
- B. Raman spectroscopy
- C. Solvent extraction followed by TLC
- D. UV-visible spectroscopy
Answer
Answer: B. Raman spectroscopy
Explanation: Raman spectroscopy allows for non-destructive, in situ analysis of ink composition on historical documents without requiring sampling or damaging the paper, making it ideal for preservation-sensitive materials.
Question 2: Which component of ballpoint pen ink primarily contributes to its forensic differentiation?
- A. Solvent
- B. Dye
- C. Binder
- D. Thickener
Answer
Answer: B. Dye
Explanation: Dyes in ink are chemically diverse and can be used to differentiate inks from different manufacturers or batches. Solvents and binders are less variable across brands.
Question 3: What is the primary forensic use of thin-layer chromatography (TLC) in ink analysis?
- A. Determine the molecular weight of ink components
- B. Visualize the fluorescence of inks under UV
- C. Separate ink components for comparison
- D. Analyze thermal degradation of ink
Answer
Answer: C. Separate ink components for comparison
Explanation: TLC is commonly used in forensic labs to separate ink dyes based on polarity, allowing analysts to compare different inks visually by observing the number and location of separated spots.
Question 4: Which instrumental technique provides the most detailed elemental composition of ink for forensic comparison?
- A. TLC
- B. GC-MS
- C. XRF
- D. ICP-MS
Answer
Answer: D. ICP-MS
Explanation: Inductively Coupled Plasma Mass Spectrometry (ICP-MS) can detect and quantify trace elements present in ink formulations, aiding in forensic ink profiling and source discrimination.
Question 5: What characteristic of ink is primarily analyzed in UV-Vis spectroscopy for forensic purposes?
- A. Molecular weight
- B. Color absorption spectrum
- C. Viscosity
- D. Ink thickness
Answer
Answer: B. Color absorption spectrum
Explanation: UV-Vis spectroscopy evaluates the light absorption profile of dyes in inks, which can be used to compare different inks based on their spectral fingerprints.
Question 6: Which method is commonly used to determine the relative age of ink on paper?
- A. Fourier-transform infrared spectroscopy (FTIR)
- B. Analysis of dye migration in humid conditions
- C. Solvent evaporation analysis via GC-MS
- D. Thermogravimetric analysis (TGA)
Answer
Answer: C. Solvent evaporation analysis via GC-MS
Explanation: GC-MS is used to detect residual solvents in ink; over time, these solvents evaporate. Comparing residual solvent content helps estimate the relative age of ink entries.
Question 7: Which ink component provides fluorescence under UV light and helps in ink differentiation?
- A. Resins
- B. Solvents
- C. Optical brighteners
- D. Pigments
Answer
Answer: C. Optical brighteners
Explanation: Optical brighteners fluoresce under UV light and are sometimes present in ink formulations, offering a method to distinguish inks that appear similar under visible light.
Question 8: Which of the following best describes the role of FTIR in forensic ink analysis?
- A. Provides elemental composition of pigments
- B. Identifies organic functional groups in ink components
- C. Determines ink viscosity and flow rate
- D. Measures pH of aqueous ink solutions
Answer
Answer: B. Identifies organic functional groups in ink components
Explanation: FTIR spectroscopy identifies specific molecular vibrations related to functional groups in organic compounds, helping to characterize resins, dyes, and solvents in inks.
Question 9: In forensic ink dating, which factor complicates the estimation of ink age on a document?
- A. Uniform paper composition
- B. Controlled storage temperature
- C. Environmental exposure variability
- D. Stable dye absorption spectrum
Answer
Answer: C. Environmental exposure variability
Explanation: Environmental factors such as temperature, humidity, and light exposure can significantly alter ink drying rates and solvent evaporation, complicating ink age estimation.
Question 10: Which of the following is a major limitation of using TLC in forensic ink comparison?
- A. Inability to detect color differences
- B. Requirement for expensive instrumentation
- C. Low sensitivity to trace components
- D. Destructive nature of the test
Answer
Answer: D. Destructive nature of the test
Explanation: TLC requires sampling ink from the document, which is destructive. This limits its application in cases involving valuable or sensitive documents where preservation is critical.