Color Spot Test As a Presumptive Tool for the Rapid Detection of Synthetic Cathinones

The overall goal of this procedure is to presumptively determine the presence or absence of a synthetic cathinone within an unknown seized material using color testory agents and associated color changes. This method can help provide law enforcement agencies with rapid, cost-effective and simple suggestions as to whether or not a synthetic cathinone may be present in a seized material. The main advantage of this technique over other color tests available is its high selectivity to other synthetic cathinone class of elicit drugs.

To begin, weigh 0.12 grams of copper nitrate trihydrate into a dry, 100mL beaker. Add 30mL of deionized, or DI water, and carefully swirl it at room temperature to dissolve all solids. Pour this solution into a 100mL volumetric flask.

Fill the solution up to the calibrate mark with DI water. This prepared solution is Reagent One. Then, weigh 0.11 grams of necuproine hemihydrate into a dry, 100mL beaker.

Add 50mL of 0.1 molar hydrochloric acid and use a glass stirring rod to promote dissolution of solids at room temperature. Pour this solution into a 100mL volumetric flask. Fill up the flask to the calibrated mark with 0.1 molar hydrochloric acid.

This prepared solution is Reagent Two. Next, weigh 16.4 grams of sodium acetate into a dry, 100mL beaker. Add 50mL of DI water and use a glass stirring rod to promote dissolution of solids at room temperature.

Pour this solution into a 100mL volumetric flask. And fill up to the calibrated mark with DI water. This prepared solution is Reagent Three.

Using a spatula, place a small, pinhead-sized amount of the unknown sample into three separate wells of a porcelain spot plate. Leave three adjacent wells empty for the blank control And add equal amounts of 4-MMC HCL to another three wells. These wells serve as a positive control, representing a synthetic cathinone reference sample.

Using a disposable pipette, add five drops of the copper nitrate solution to each sample well in addition to the blank and positive control wells. Then, using a second disposable pipette, add two drops of the neocuproine solution to each sample well in addition to the blank and positive control wells. Finally, using a third disposable pipette, add two drops of the sodium acetate solution to each sample well in addition to the blank and positive control wells.

At this point, the solution turns light blue. Place the porcelain spot plate directly onto an electric hotplate set at 80 degrees Celsius. After heating for 10 minutes, observe the color change by the naked eye using a white background to better visualize the color changes.

Make a note or take a photo of the final color change. Representative results of a blank control and 4-MCC HCL as a synthetic cathinone positive control are shown here. In general, a yellow-orange color change after heating is considered a positive result.

However, this color can vary in intensity as seen with N, N-dimethylcathinone HCL which is dark colored as well as with 3 4-dimethylmethcathinone HCL which is light colored. Other positive results include 2 4 5-trimethylmethcathinone HCL in a piperazenic analog, a false positive. Conversely, representative compounds producing negative results are shown here.

The first is a false negative result produced by MDPBP HCL, while the other three are true negative results of an amino acid, drug precursor, and amphetamine. Although the drug precursor is yellow-orange color, this occurred before the heating step. Finally, reactions with cathinone mixtures are not affected and show positive results.

After watching this video, you should have a good understanding of how to perform a simple color test to detect the presence of synthetic cathinones in seized material. While attempting this procedure, it is important to remember that this protocol is intended to be used for presumptive identification. In a forensic context, sophisticated instrumentation, such as mass spectrometry, must be performed in order to confirm any identifications.