Yes this is possible. Anyone vendor who says their products are 100% pure though are yanking your chain. Most product purity claims I've seen range between 98-99.5% purity and I don't play when it comes to getting quality shit. Still though, if you're in doubt, ask for the GCMS/NMR analysis to confirm their purity claims. These can be and have been faked by scammers before, but it's uncommon, and this is also a good way to find out who is more of a serious lab and who is a retail vendor. In the name of harm reduction, it's better to work more directly with the manufactuer than some dude on the net who bought some shit and has no way to verify the purity or the identity of the compounds he is selling. Some retailers though go to great lengths to assure quality though and sometimes retailers are more practical to do business with. Right before EK got shut down there was talk of making vendors who claimed any purity percentage of their product had to send in a sample to an independent lab for confirmation and they would get a little icon certifying their claims. Sadly this never came to fruition, but maybe it will come into being on other forum sites.