Heroin Purity Test KitThis heroin purity test is a quick test for heroin that will give you an idea about its purity. With this test you are able to find out whether and how much the heroin has been cut. Use it after youve tested your sample with the Opiates (Mecke) test, which gives an indication of whether or not Heroin is present in the first place. Dealers cut heroin to increase their profit margins. The substances used for cutting are sometimes harmless, but sometimes