Evidence-Based Evaluation Of The Analytical Schemes In ASTM E2329-17 Standard Practice For Identification Of Seized Drugs For Methamphetamine Samples

• NCJ Number: 308683
• Journal: Forensic Chemistry Volume: 38 Dated: May 2024 Pages: 100560
• Author(s): Jeremy S. Triplett; Jeff Salyards; Sandra E. Rodriguez-Cruz; Jeremiah A. Morris; Darryl Creel; Joseph Zemmels; Megan Grabenauer
• Date Published: May 2024
• Grant Number(s): 2016-MU-BX-K110
• Agencies: NIJ-Sponsored
• Publication Type: Research (Applied/Empirical)

Annotation

This study assesses the analytical schemes in ASTM E2329-17 standard practice for identification of seized drugs for methamphetamine samples.

Abstract

The results of the study of the analytical schemes in ASTM E2329-17 standard practice for identification of seized drugs for methamphetamine samples showed good accuracy; sensitivity was 1.000 for all analytical schemes with 1-specificity (the false-positive rate) ranging from 0.000 to 0.250 when ASTM E2329-17 compliant analytical schemes were used. When only a single technique was used, accuracy was generally not as good; sensitivity ranged from 1.000 to 0.091, and 1-specificity ranged from 0.000 to 0.245. This study involved 71 forensic seized drug laboratories analyzing 65 total samples; 17 were ground-truth positive (i.e., they contained methamphetamine or cocaine); 48 were ground-truth negative (i.e., they did not contain methamphetamine or cocaine). The positive samples were prepared at several target-analyte concentrations and combined with common cutting agents. The negative samples were designed to be challenging and prepared to contain positional isomers of methamphetamine. Participants were sent two different sample sets. In the first, they were directed to only use a single, pre-selected analytical technique. In the second, they were directed to use a pre-selected analytical scheme consisting of multiple techniques in compliance with ASTM E2329-17. The results of the study showed good accuracy; sensitivity was 1.000 for all analytical schemes with 1-specificity (the false-positive rate) ranging from 0.000 to 0.250 when ASTM E2329-17 compliant analytical schemes were used. When only a single technique was used, accuracy was generally not as good; sensitivity ranged from 1.000 to 0.091, and 1-specificity ranged from 0.000 to 0.245. (Published Abstract Provided)