Questioned Document: Ink Dating Methods (Aginsky, Brunelle, ASTM E2789)

This mock covers the forensic science of ink dating and ink examination as tested in UGC-NET Paper II Unit IX (Questioned Documents). Core analytical methods examined include phenoxyethanol (PE) quantification by GC-MS under the Aginsky protocol, thin-layer chromatography (TLC) comparison by the Brunelle method, High-Performance Liquid Chromatography (HPLC) with diode array detection for dye profiling, Laser Desorption Ionisation Mass Spectrometry (LDI-MS) for non-destructive direct-surface ink identification, and Raman spectroscopy for in-situ dye characterisation. The mock also covers ASTM E2789 (Standard Guide for Ink Analysis) and its distinction from ASTM E1789 and ASTM E2390, the US Secret Service Ink Reference Collection (IRC) and its role in establishing earliest-possible writing dates, the logarithmic solvent-loss curve governing PE decay, static versus dynamic (accelerated) aging, sequence-of-strokes examination at ink intersections, and the reliability limitations of the Aginsky method in court testimony.

In the Indian forensic context, the mock addresses the questioned document capabilities of CFSL Kolkata and the Government Examiner of Questioned Documents (GEQD) offices including GEQD Shimla. It tests knowledge of how CFSL reports are tendered in Indian courts under Section 293 CrPC 1973 (now Section 336 BNSS 2023) and the practical alternatives used by Indian laboratories when the USSS IRC database is not directly accessible. Questions test both the scientific principles and the procedural and legal framework within which ink examination evidence is used in Indian criminal and civil proceedings.

Topics covered:

• Phenoxyethanol (PE) composition, decay kinetics, and role as Aginsky age marker
• Brunelle TLC method and US Secret Service Ink Reference Collection (IRC)
• Aginsky GC-MS protocol: PE/reference ratio, logarithmic decay curve, 1-2 year reliability limit
• ASTM E2789, E1789, and E2390: scope distinctions and non-mandatory Guide status
• Static vs dynamic (accelerated) aging: kinetic scaling limitations
• Sequence-of-strokes examination: oblique-light microscopy and ESDA
• LDI-MS: non-destructive direct-surface dye mass fingerprinting
• CFSL Kolkata and GEQD Shimla: institutional roles and Indian court tendering

Allow 30 minutes.