I bought some GBL recently at first it was strong but latter the effect became weaker and weaker,I put it in a normal amber bottle and keep it in a dry place,How come my GBL seems to be rotten by timeIs there a way to save it like purification or is it the problem comes from my way of presevatiom?Hope some pone can help me to bring back the old GBL with strong effectOr how to make it strongThnkyou for you help