Forensic Chemistry

What forensic chemistry actually does inside a casework workflow, where it sits relative to forensic physics, biology and toxicology, the sampling and chain-of-custody discipline for chemical evidence, and the certified reference materials and quantification baseline (LOD, LOQ, measurement uncertainty) that decide whether an analytical result is admissible.

The controlled-substance legal frame across India (NDPS 1985), the US (CSA), the UK (MDA 1971) and the EU (Council Decision 2005/387/JHA), the chemistry and cutting-agent profile of heroin and fentanyl analogues that drove the US overdose crisis, and the stimulant chemistry (cocaine, amphetamines, methamphetamine, MDMA) that anchors daily seizure casework worldwide.

Cannabis cannabinoids (THC, CBD, HHC) and synthetic cannabinoid waves (K2/Spice), classical hallucinogens (LSD, psilocybin, DMT), depressant classes (benzodiazepines, barbiturates, GHB), and the novel psychoactive substance treadmill of cathinones, designer benzodiazepines and synthetic opioids that has reshaped forensic chemistry casework since 2010.

Colour-test chemistry (Marquis, Mecke, Duquenois-Levine, cobalt thiocyanate, Scott test) and the SWGDRUG identification tiers that escalate from a presumptive screen through TLC, UV, GC-MS and LC-MS/MS to a court-defensible identification, with NDPS-style small-and-commercial quantity reporting baked in.

Ethanol analysis by GC-headspace and the blood-alcohol baseline that every drunk-driving prosecution rides on, the methanol chemistry behind hooch tragedies (2022 Bihar, 2009 Gujarat, US Prohibition-era adulteration), and the statutory frame around denatured spirit, country liquor and excise-controlled beverages.

Milk and dairy adulteration (melamine, urea, detergent), the chemistry behind edible-oil and spice adulteration (Sudan dyes in chilli, lead chromate in turmeric, argemone oil in mustard), and the cosmetics chemistry (heavy metals, banned colourants, formaldehyde release) regulated under PFA / FSSAI / US FDA / EU REACH frameworks.

Low and high explosives, primary and secondary classification, the chemistry of conventional military and commercial high explosives (TNT, RDX, PETN, HMX, Composition B, C-4, Semtex), the improvised explosives that dominate modern IED casework (TATP, ANFO, urea nitrate), and the post-blast residue sampling and IMS, GC-ECD, LC-MS/MS, ion chromatography workflow that links a fragment to a charge.

Fire chemistry, pyrolysis and the arson investigation framework, the passive-headspace concentration on activated carbon strips (ASTM E1387 / E1618) and GC-MS pattern recognition that identifies petroleum-distillate accelerants (petrol, kerosene, diesel), and the chemistry of petroleum products, lubricants and transformer oil that turn up in industrial casework.

Three-component gunshot residue (lead, antimony, barium) and SEM-EDX particle morphology, the lead-free / green primer chemistry shift that has reshaped GSR detection since the 2000s, and the chemistry of firing-distance determination by Griess test and sodium rhodizonate that complements the ballistics range-determination work.

Ink chemistry (gel, ballpoint, toner, inkjet) by TLC, HPLC, Raman and video spectral comparator workflows, the chemistry of counterfeit currency security features, the chemical warfare agent classes (sarin, VX, mustard, novichok) and OPCW designated laboratory network, and the ISO 17025 / NABL / SWGDRUG / ASTM / ENFSI accreditation regime that decides what a forensic chemistry lab can certify in court.