There is a large variation in quality, reliability and control. The SEMOPTICS Samplers and Kits offered by SPI Supplies are for Case Work and are designed for acceptance in court room settings. While they can also be used for investigative examinations, we want to stress that the SEMOPTICS Samplers and Kits were designed specifically for police type work. They have built into them of controls one would expect for this kind of application. These Samplers and Kits should not be confused with cheaper samplers and kits that do not meet the test for submission in evidence in a court of law.
Some samplers on the commercial market require the investigator to apply the sticky surface to the mount in the field. Others require the application of isopropyl alcohol in order to activate the sticky surface. We do not offer such samplers because of the likelihood of contamination and the difficulty on the part of the investigator, in a court room setting to prove that contamination did not occur at this critical step of the process.
The SEMOPTICS samplers stand out from other alternatives in several ways. The metal used for the SEM mount is a special "forensic" alloy which means the alloy used is free of the important elements of GSR analysis. The alloy is assay certified from a chemical laboratory as to the actual composition of that particular batch of aluminum.