Purity test kits are quantitative test kits that tell you the amount of active ingredient in a drug sample. For example, they can tell you how much MDMA is in an ecstasy tablet, or how much psilocybin is in a gram of dried mushrooms. Unlike standard reagents that simply detect the presence of a substance, purity test kits tell you how much of the substance is present, or how pure the sample is (hence the name). Just remember that purity here means “percentage purity” or percentage of active ingredient. It does not mean pure as in unadulterated or uncontaminated.

Purity test kits use chemical reagents that react with the active ingredient in a sample to produce a color change. Because the volume of reagent and the amount of the substance added to it are both precisely measured, the intensity of the color change will vary depending on the amount of active ingredient in the sample. You only need to test a small amount, and the result can be evaluated visually with a color chart.

The basic process involves four stages:

1. Extraction – The active ingredient in the drug sample is extracted out of whatever medium it resides—such as blotter paper, mushroom fungal cells, or an ecstasy tablet—and is dissolved into a liquid (the extraction fluid). There it becomes accessible to the reagent.
2. Reaction – A specific amount of the extraction fluid is then added to a specific amount of the reagent (or vice versa) to produce a color reaction.
3. Calibration – A color chart is calibrated to match the amount of active ingredient that was tested, or the percentage of active ingredient in the tested sample.
4. Evaluation – The color of the liquid in the vial is then visually matched against the color chart to obtain the result.

If used correctly our purity test kits have good accuracy. We developed them using GCMS verified drug standards, and every batch is quality control tested prior to shipping.

That said, there is some room for error. Interpretation of the color charts requires good vision and bright light. Some people perceive colors differently than the average person, so it’s best to have multiple people evaluate the result together.

There is also room for human error when weighing the drug sample. And some milligram scales may not be perfectly accurate, which may slightly skew the result. Taken as a whole, however, these error margins are small. Keep in mind also that even high performance liquid chromatography (HPLC) has a 10% margin of error.

The kits consist of modified versions of standard reagents, along with extraction fluids. The MDMA kit consists of a modified Marquis reagent. The extraction fluid is simply distilled water with an option for added heptane when the kit is being used to test an ecstasy tablet. (The heptane floats on top of the water and traps colored dyes in the tablet, leaving the MDMA diluted in the water below.)

The LSD kit consists of a modified Hofmann reagent, and methanol is used as the extraction fluid, which pulls out the LSD from blotter paper.

The psilocybin kit uses yet another modified version of Hofmann reagent, and the extraction fluid is a precise mixture of distilled water, citric acid, and ascorbic acid. The citric acid helps break down the fungal cell walls, pulling out the psilocybin and psilocin. The ascorbic acid is an antioxidant that prevents the breakdown of the alkaloids.

For more information on how our kits are made see our article, How to Make a Purity Test Kit.

Standard reagents have been around a long time and are used to identify the predominant drug in a sample. They come in multi-use dropper bottles that can perform 50 to 75 tests each. We sell standard reagents from our closely associated nonprofit, Grassroots Harm Reduction. All proceeds from their sale are donated to the nonprofit.

Only if you’re not sure whether you actually have MDMA. The MDMA QTest can turn a similar color with other drugs, such as MDA and 5-MAPB. Therefore, if you aren’t sure that you really have MDMA, use a standard MDMA test kit first.

Yes. The kits contain solvents and acids which can burn the skin and eyes. So wear the nitrile gloves always. We also strongly recommend wearing protective eye goggles. We’re not just saying this in order to cover our ass for liability reasons. Accidents happen all the time. Vials spill. Liquids splash. The cat gets out and jumps on the work table. Remember, protective gear is harm reduction! 🙂