Development of a Microcrystal Test for the Detection of Clonazepam

Microcrystal tests are chemical microscopy techniques that date back to the 1800s. Recently they have been used as an analytical technique for distinguishing certain classes of drugs in the forensic sciences. Some advantages of microcrystal tests are they’re relatively inexpensive, fairly simple to conduct, and use very little drug sample. There are disadvantages to this technique, however, including the need for comparison standards, and a clean sample. While some drugs, such as cocaine and heroin, have well validated microcrystal tests, other classes of drugs, i.e. the benzodiazepines have not been extensively studied for this purpose. The goal of this project, therefore, was to optically characterize and develop a microcrystal test that could be used to detect clonazepam. Clonazepam is a benzodiazepine drug is sold under the trade name Klonopin®. It is known for its sedative-hypnotic properties and has therapeutic uses as an anticonvulsant and anxiolytic. Benzodiazepines have been abused for these sedative effects, but are more popularly known for their use in drug-facilitated sexual assaults. In the past decade emergency department visits involving the abuse and misuse of benzodiazepines have increased, indicating the benefit of validated microcrystal tests for their detection. A microcrystal test was successfully developed that is able to detect clonazepam in its pharmaceutical preparations at all of its therapeutic dosages. The test involves the addition of acetone and a 10% platinum chloride solution to microgram quantities of clonazepam. The presence of clonazepam is indicated by the formation of rosettes made of colorless, blunt-ended rods. No other drug is known to exhibit the same reaction with these reagents making the test a good candidate for use in forensic lab settings.