I totally agree with this and have seen this time and time again. The 100% pure on the label is likely not accurate. When an analysis is performed on a non-drug product like this, it is very minimal and generally performed with instruments that aren't sensitive enough to truly see the related substances, excipients or impurities.

These flakes are likely manufactured by some type of heating/evaporating/cooling process. This is one of the places where impurities find their way into the product.

If I were considering this product, I would probably call the company and ask them to provide me a Certificate of Analysis. If they are a good company and doing things above board, they should be able to provide this C of A easily and match it to the batch on your product. I'd want to know both the purity and potency before I made a solution of this.

Just my 2 cents....