Instrumental Techniques
Atomic and molecular spectra, the optical / atomic / X-ray / chromatographic / mass-spec / magnetic-resonance / microscopy / radiochemistry families, hyphenated workflows and the ISO 17025 quality system that decides what an Indian forensic-science lab can certify in court, end to end.
- 76hours
- 21topics
- 7modules
Foundations of instrumental analysis
What instrumental analysis actually does in a forensic-science workflow, the physics of atomic and molecular spectra that every spectroscopic technique rides on, and the sample preparation, calibration and reference-standard discipline that sits before any instrument is switched on.
Start module- Introduction and Scope of Instrumental Techniques in Forensic ScienceWhat instrumental techniques actually do inside an Indian forensic case, where each major family (optical, atomic, chromatographic, mass spec, magnetic resonance, microscopy) sits in the workflow, and the working examiner's day-to-day instrument map at CFSL, SFSL and AIIMS forensic units.12 min
- Atomic and Molecular Spectra FundamentalsThe physics every spectroscopic technique rides on: electronic, vibrational and rotational energy levels, line vs band spectra, the electromagnetic spectrum from gamma to radio, and how absorption, emission and scattering each probe a different slice of the same molecule.14 min
- Sample Preparation, Purification and Instrument CalibrationWhat happens before the sample reaches the instrument: extraction, clean-up, derivatisation, dilution, internal-standard spiking, then standardisation and calibration of the instrument with certified reference materials and the linearity, LOD, LOQ and recovery checks that make the result court-defensible.22 min
Optical and luminescence spectroscopy
UV-Vis absorption and the Beer-Lambert law, fluorescence and phosphorescence as detection layers, and the infrared region (FTIR and ATR-FTIR) that fingerprints organic molecules and unknown solids in the working examiner's casebook.
Start module- UV-Vis Spectrophotometry and the Beer-Lambert LawBeer-Lambert A = epsilon b c, dispersive vs diode-array UV-Vis instruments, the chromophore-to-wavelength mapping that lets a forensic chemist quantitate paracetamol at 245 nm or barbiturates at 240 nm, and the limits of UV-Vis as a presumptive vs confirmatory technique.16 min
- Fluorescence and Phosphorescence SpectroscopySinglet and triplet excited states, the Jablonski diagram, fluorescence quantum yield and phosphorescence lifetime, and how Indian forensic labs use fluorescence for quinine in tonics, fluorescent dyes in inks, document forgery under UV, and the polyaromatic hydrocarbon panels that ride GC-MS confirmation.14 min
- Infrared Spectroscopy: FTIR and ATR-FTIRFourier-transform infrared (FTIR) and attenuated total reflectance (ATR-FTIR), the fingerprint region 4000-400 cm-1, sample modes (KBr pellet, nujol mull, ATR film), and how an Indian SFSL uses FTIR to identify unknown white powders, paint chip layers, suicide-note tablets and explosive residue.15 min
Atomic and X-ray spectroscopy
Flame and graphite-furnace atomic absorption (AAS) for metals, ICP-OES and ICP-MS for multi-element panels at trace level, and X-ray fluorescence (XRF) and diffraction (XRD) for elemental and crystalline phase identification of paint, glass, gunshot residue and forged documents.
Start module- Atomic Absorption Spectrometry (AAS): Flame, Graphite Furnace and Cold VapourHollow-cathode lamp principles, flame AAS for Pb/Cu/Zn/Cd, graphite-furnace AAS for As/Hg/Cd at ppb level, cold-vapour AAS for mercury, hydride generation for arsenic, the spectral and chemical interferences with their background-correction methods, and how these decide an Indian SFSL's metal-poison casework.14 min
- Atomic Emission: ICP-OES and ICP-MSArgon plasma at 6000-10000 K, simultaneous multi-element OES detection, quadrupole and sector ICP-MS at parts-per-trillion, isotope-ratio analysis for source attribution, the advantages of ICP over AAS, and how CFSL Chandigarh and FSL Madhuban Sector 14 run their toxic-metal panels.12 min
- X-Ray Spectroscopy: XRF, XRD and X-Ray AbsorptionEnergy-dispersive and wavelength-dispersive X-ray fluorescence (EDXRF, WDXRF) for elemental composition of paint, glass, ink and gunshot residue; X-ray diffraction (XRD) for crystalline phase identification; and X-ray absorption / fluorescence as the non-destructive elemental probes that carry many Indian forensic-physics cases.14 min
Chromatography
Paper, column, thin-layer and high-performance liquid chromatography (HPLC, UHPLC, HPTLC), and gas-liquid chromatography (GLC) with FID, ECD and NPD detectors: the separation toolkit that anchors drug analysis, fire-debris work, explosives and toxicology at every Indian state SFSL.
Start module- Chromatography Fundamentals: Paper, Column and TLCStationary and mobile phase, the Rf concept, theoretical plates and resolution, paper chromatography for inks and dyes, classical column chromatography for purification, and TLC with silica gel 60 F254 plates and the Marquis/Mayer/Dragendorff visualisation set used at every Indian forensic chemistry bench.11 min
- Gas-Liquid Chromatography (GLC): Columns, Carriers and DetectorsCapillary columns (DB-1, DB-5, DB-WAX), helium and hydrogen carriers, FID for general organics, ECD for halogenated pesticides, NPD for drugs and pesticides, headspace GC for volatiles, and the Indian SFSL workflows for fire-debris analysis, ethanol Section 185 MV Act and pesticide residue.15 min
- HPLC, UHPLC and HPTLC for Forensic AnalysisReverse-phase C18 columns, isocratic vs gradient elution, UV-DAD and fluorescence detectors, UHPLC sub-2 micron particles for fast separations, and HPTLC with densitometric scanning for ayurvedic and herbal product fingerprinting at NIPER Mohali, NIN Hyderabad and FSSAI labs.19 min
Mass spectrometry
Mass spectrometer architecture (sample chamber, ionisation source, mass analyser, vacuum, detector), tandem MS workflows (GC-MS, LC-MS/MS, Q-TOF and Orbitrap), and the spectral interpretation skill that turns a presumptive screen into a court-defensible identification.
Start module- Mass Spectrometry: Principles, Ionisation and Mass AnalysersSample inlet, ionisation sources (EI, CI, ESI, APCI, MALDI), mass analysers (quadrupole, ion trap, time-of-flight, Orbitrap, magnetic sector), vacuum systems and electron multipliers, and the working examiner's mental model of what a mass spectrum is actually showing.19 min
- Tandem Mass Spectrometry (MS/MS) and Spectral InterpretationTriple-quadrupole MRM transitions, Q-TOF accurate mass, NIST library matching for GC-MS EI, the molecular ion vs base peak vs fragment ion logic, deuterated internal standards, and how an Indian forensic-toxicology report under BSA 2023 Section 63 anchors itself to two MRM transitions plus an IS.15 min
Raman, NMR, microscopy and radiochemistry
Raman spectroscopy as a non-destructive complement to IR, nuclear magnetic resonance (NMR) for structural elucidation, scanning electron microscopy with EDXRF for high-magnification elemental imaging, and the radiochemistry methods (carbon dating, neutron activation analysis) that anchor questioned-document and trace-evidence work.
Start module- Raman Spectroscopy and Comparison with IRThe Raman effect (inelastic scattering), the complementarity rule with IR (symmetric vs asymmetric vibrations), surface-enhanced Raman (SERS), portable Raman in airport screening, and the Indian forensic uses for paint, plastic, gemstone and explosive residue identification.14 min
- Nuclear Magnetic Resonance (NMR) Spectroscopy1H and 13C NMR principles, chemical shift, spin-spin coupling, integration, instrument architecture (superconducting magnet, RF probe, lock and shim), interpretation of a basic spectrum, and Indian forensic uses for novel psychoactive substances (NPS), seized cannabis profiling and ayurvedic adulterant work.15 min
- Scanning Electron Microscopy (SEM) with EDXRFElectron-beam interaction with a sample, secondary and back-scattered electron imaging, EDXRF elemental mapping, the SEM-EDS gunshot-residue particle (Pb-Sb-Ba) workflow, fibre and paint cross-section examination, and the case for SEM-EDS over optical microscopy in Indian forensic-physics work.15 min
- Radiochemistry: Measurement of Radioactivity, Carbon Dating and Neutron Activation AnalysisGeiger-Muller counters, scintillation and semiconductor detectors, alpha/beta/gamma counting, accelerator mass spectrometry (AMS) for radiocarbon dating of questioned documents and antiquities, neutron activation analysis (NAA) for trace elements in hair and bullet lead, and BARC's role in Indian forensic radiochemistry.20 min
Hyphenated techniques and quality management
Hyphenated workflows (GC-MS, LC-MS, GC-FTIR) that combine separation and identification in a single run, and the ISO 17025:2017 quality system: method validation, measurement uncertainty, traceability, reference materials, proficiency testing and the NABL accreditation that decides what an Indian forensic-science lab can certify under BSA 2023 Section 63.
Start module- Hyphenated Techniques: GC-MS, LC-MS and GC-FTIRWhy coupling separation with identification became the gold standard, the GC-MS interface with electron multiplier and quadrupole, LC-MS/MS with ESI and APCI, GC-FTIR for vapor-phase fingerprinting, and how an Indian state SFSL chains TLC presumptive screening into LC-MS/MS confirmation.20 min
- ISO 17025 and Quality Management in Forensic LaboratoriesISO 9001 vs ISO 17025:2017, the management and technical requirements for a testing lab, NABL accreditation in India, quality control vs quality assurance vs total quality management, reference standards and certified reference materials, and the audit trail that anchors a BSA 2023 Section 63 certificate.14 min
- Method Validation, Measurement Uncertainty and Proficiency TestingThe validation parameters every forensic method must establish (accuracy, precision, linearity, LOD, LOQ, ruggedness, robustness), the GUM approach to measurement uncertainty, control charts and trend analysis, and the proficiency-testing schemes (NABL PT, NIST/NIJ, Collaborative Testing Services) that keep an Indian lab honest.9 min