sentences:  This increases the likelihood that a substance might have a unique profile of results and makes the tests more useful.Other reagents are discussed in scientific literature but limited applications mean they may not be sold for consumer testing.The zimmermann reagent for benzodiazepines is a good example - its use is limited to benzodiazepines, and when these are mis-sold it is usually by substitution of a different benzodiazepine, rendering the test unuseful for consumers.