The concentration detected was approximately five μg/mL and was very easily noticed employing a simple extraction technique accompanied by GC/MS analysis. GBL can be found in cheese flavourings but generally ends in a content material of 0.0002% GBL in the final foodstuff. It looks like you have been misusing this https://bestchemshop.com/product-category/gamma-butyrolactone-gbl-liquid/