Forensic Ballistics: GSR: SEM-EDX and ICP-MS Quantification
Published:
Questions
30
Duration
30 min
Faculty-reviewed
0
Updated
24 May 2026
About this mock
UGC-NET Forensic Science Unit V advanced drill on gunshot residue characterisation, instrumental quantification, and reporting standards. Hard-band coverage on the three-component Pb-Ba-Sb characteristic particle, the two-component Pb-Sb and Ba-Sb consistent category, and the single-element commonly-occurring band under ASTM E1588-20 Standard Practice for Gunshot Residue Analysis by SEM/EDS. Detailed sub-topic drill on backscattered electron imaging for heavy-metal atomic-number contrast, energy-dispersive X-ray spectrometry with Si(Li) and silicon-drift detectors, primer element K-lines and L-lines, peak overlaps (Pb Mα at 2.342 keV with S Kα at 2.307 keV), and the typical 0.5 to 5 micrometre spheroidal-particle band that condensation cooling produces.
The ICP-MS half covers sub-ng/cm² limits of detection for lead, barium and antimony on cotton-swab eluates digested in 0.1 M nitric acid, the 208Pb, 138Ba and 121Sb isotopes commonly monitored, matrix-suppression effects from sodium and the internal-standard selection (rhodium, indium, bismuth). Sample-collection coverage spans adhesive aluminium stubs for SEM and cotton swabs for ICP-MS, hand-versus-face deposition zones, and the six-hour persistence window for the shooter's hands. Lead-free Sintox-primer challenges are drilled on the gallium, titanium, zinc and strontium markers with DDNP base. Calibrated for MSc Forensic Science aspirants targeting Paper II top-decile scores on Unit V.
Topics covered:
- Characteristic, consistent and commonly-occurring GSR particle categories
- SEM backscattered imaging and EDX elemental confirmation
- Particle morphology and the 0.5 to 5 micrometre size band
- ICP-MS quantification with isotope selection and internal standards
- Adhesive stub and cotton swab collection protocols
- Hand, face and clothing deposition zones and persistence dynamics
- Sintox lead-free primer markers and ASTM E1588-20 inclusivity
- ENFSI Guideline for GSR Analysis and reporting categories
A timed self-audit for casework-grade GSR competence. Allow 30 minutes.
Sources & references
Questions in this mock are written and verified against the following sources. Citations are recorded per question and shown in the explanation after submission.
- cited in 11 questions
ASTM E1588-20 Standard Practice for Gunshot Residue Analysis by SEM/EDS
ASTM E1588-20 section 7 on spectral interpretation, Pb Mα / S Kα disambiguation through Pb Lα cross-confirmation at 10.55 keV
Open source - cited in 7 questions
Skoog, D.A., Holler, F.J. and Crouch, S.R. — Principles of Instrumental Analysis, 7th Edition, Cengage 2018
Chapter 12 on X-ray spectroscopy, over-voltage rule for L-line excitation in SEM-EDS work
- cited in 4 questions
Romolo, F.S. and Margot, P. — Identification of Gunshot Residue: A Critical Review, Forensic Science International 119 (2001) 195
Section on methodology, complementarity of SEM-EDX per-particle identification and ICP-MS bulk quantification in modern GSR practice
Open source - cited in 4 questions
Schwoeble, A.J. and Exline, D.L. — Current Methods in Forensic Gunshot Residue Analysis, CRC Press 2000
Chapter 2 on GSR particle physics, typical 0.5 to 5 µm size band for deposited primer-residue particles
Open source - cited in 2 questions
ENFSI Best Practice Manual for Chemographic Methods in Gunshot Residue Analysis
ENFSI BPM-CHM section on end-to-end GSR practice, collection through court-level weight assessment alongside ASTM E1588-20
Open source - cited in 1 question
Saferstein, Richard — Criminalistics: An Introduction to Forensic Science, 12th Edition, Pearson 2018
Chapter 18 on firearms and tool marks, GSR deposition zones on a shooter's hand, face and clothing for a hand-held pistol grip
- cited in 1 question
Heard, Brian J. — Handbook of Firearms and Ballistics, 2nd Edition, Wiley-Blackwell 2008
Chapter 9 on Gunshot Residue, the lead-styphnate / barium-nitrate / antimony-sulfide primer composition
Open source
How our mocks are built
Questions are written and edited by the ForensicSpot team and cited from peer-reviewed forensic textbooks, official syllabi and primary case law. Each one is verified before publishing. Detailed explanations show after you submit, so the test stays a real test. See a mistake? Tell us.
Common questions
What does the Forensic Ballistics: GSR: SEM-EDX and ICP-MS Quantification mock cover?+
UGC-NET Forensic Science Unit V advanced drill on gunshot residue characterisation, instrumental quantification, and reporting standards. Hard-band coverage on the three-component Pb-Ba-Sb characteristic particle, the two-component Pb-Sb and Ba-Sb consistent category, and the single-element commonly-occurring band under ASTM E1588-20 Standard Practice for Gunshot Residue Analysis by SEM/EDS. Detailed sub-topic drill on backscattered electron imaging for heavy-metal atomic-number contrast, energy
How many questions and how long is the test?+
30 multiple-choice questions, 30 minutes total. Difficulty: hard. Tier: Premium.
Who is this mock for?+
Forensic science students and aspirants who want timed, exam-style practice with explanations and verified source citations on Forensic Ballistics, NET. Useful for postgraduate entrance preparation and for BSc / MSc forensic students testing their recall under time.
Are the questions reviewed?+
Each question carries a verified source citation. Faculty review for individual questions is in progress.
Do I need an account to take this mock?+
Yes, a free ForensicSpot account is required to start a timed attempt — this lets you save progress, see per-question explanations after submission, and track your topic-level performance over time.