Sampling Methods for Microanalysis
Mary L. Stellmack
R&D - September 17, 2014
In order to identify contaminants in industrial products, it’s sometimes necessary to send samples of the contaminated material to a laboratory for analysis. The choice of sampling method and the selection of a shipping container are critical to ensure that a representative sample is obtained, and no additional foreign material (FM) is added to the sample during transport to the laboratory.
Selecting a container
Initially, consideration should be given to the choice of container for a sample and its integrity. The container shouldn’t be substantially larger than the sample, so the sample will be immediately visible and obvious to the laboratory. If a sample consists of a few non-homogeneous particles that may crumble into smaller particles during shipping, a small vial would be a better choice than a large ziplock bag. Any scoops, tubing, tools or wipes used to transfer the samples should be dry and free of visible debris. Vials or glass jars should be free of visible contaminants prior to adding the sample. Ideally they should be washed, rinsed well and dried in a clean environment, or “particle-free”, cleanroom-type containers can be purchased for special applications.