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Category a Method

Definition

An analytical method that provides the highest level of discriminating power in drug identification, generating structural or molecular fingerprint information. Category A methods include FTIR, GC-MS, LC-MS/MS, NMR, Raman spectroscopy and X-ray diffraction. At least one Category A method is required for any SWGDRUG-compliant drug identification.

Related terms

Category B Method
An analytical method with intermediate discriminating power, measuring a characteristic but less structurally specific property. Includes UV-Vis spectroscopy, TLC, GC without MS,...
ENFSI Drugs Working Group (DWG)
European Network of Forensic Science Institutes Drugs Working Group. Publishes best-practice manuals for drug analysis aligned with SWGDRUG tiering principles, operates an...
Internal Standard (IS)
A compound chemically near-identical to the analyte, often a deuterated isotopologue (d3-morphine, d5-EDDP, d5-alprazolam, pyrene-d10), spiked into every sample at a known...
ISO/IEC 17025:2017
The international standard specifying general requirements for the competence of testing and calibration laboratories. Covers management (document control, non-conforming work, audits) and...
Measurement Uncertainty (MU)
A quantified parameter associated with a result that characterises the dispersion of values reasonably attributable to the measurand. Estimated by the GUM...
Multiple Reaction Monitoring (MRM)
An LC-MS/MS acquisition mode in which the first quadrupole (Q1) selects a precursor ion at a specific m/z, the second (Q2) fragments...
NDPS Small Quantity / Commercial Quantity
Quantity thresholds defined in the schedules to India's NDPS Act 1985 that determine the severity of criminal charge and applicable mandatory minimum...
Orthogonality (Analytical)
The requirement that two methods used in a drug identification measure genuinely different physical or chemical properties. Orthogonality ensures that the probability...
SWGDRUG
Scientific Working Group for the Analysis of Seized Drugs, established in 1997 by the US DEA and the Office of National Drug...

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