Related Experiment Video
Updated: Sep 11, 2025

Standardized Method for Measuring Collection Efficiency from Wipe-sampling of Trace Explosives
Published on: April 10, 2017
The importance of sample preparation method in testing air jet removal efficiencies of trace explosive particles
Robert Fletcher1, Alexander Bulk2, Matthew Staymates1
1Materials Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA. robert.fletcher@nist.gov.
Abstract:
In particular, we study the influence of sample preparation methods on the removal efficiency of cyclotrimethylenetrinitramine (RDX) particles from clean glass slides via air jet impingement. Five different sample preparation methods are investigated covering a range of potential contamination scenarios. These include (1) dry sieve, (2) artificial fingerprint without sebum, (3) artificial fingerprint with sebum, (4) dry transfer and (5) direct pipetting of an aqueous suspension. Results show clear differences in RDX particle removal efficiency with sample preparation method, with a range from undetectable to almost 90%. A custom aerodynamic sampling testbed was developed for the testing that tightly controls air jet pressure, standoff distance and impingement angle while minimizing particle losses to the lab environment. Differential interference contrast (DIC) light microscopy was used to image RDX particles ranging in diameter from 5 μm to over 100 μm before and after jet impingement, with semi-automated post-processing used to determine total particle removal efficiency. The results of this study suggest that testing and evaluation procedures used for trace contraband screening systems that utilize non-contact aerodynamic sampling should consider the role of test sample preparation when designing and defining testing methodologies.
More Related Videos
Related Concept Videos
Sample Preparation for Analysis: Overview
Bulk or large solid samples are typically reduced in size using grinding, crushing, or milling techniques to increase the...
Sampling Methods: Sample Types
Solid samples include a variety of substances, such as sediments from water bodies, soil, metals, and biological tissues. Two standard methods for extracting sediments from water bodies are grab sampling and piston coring. Grab sampling involves using a device to collect a discrete sediment sample from the bottom of a water body with minimal disturbance. Grab samples do not always represent the entire area due to...
Atomic Absorption Spectroscopy: Atomization Methods
Sample Preparation for Analysis: Advanced Techniques
Acid digestion with strong acids is commonly used to dissolve inorganic materials that are insoluble (do not dissolve) in water. This method can be useful for...
Atomic Absorption Spectroscopy: Lab
Solutions containing organic solvents, such as low-molecular-mass alcohols, esters, or ketones, enhance absorbances by increasing...
Gas Chromatography: Sample Injection Systems
Two primary injection methods are used...

