Many reports have come in that nicotine sold by a US pharma vendor is many times stronger than the label states. A 100mg sample is said to have tested at 245mg strength. This means any resulting e-liquid made will be over double the expected strength. This may mean that 36mg liquid you make in good faith could actually be 88mg. You should not touch concentrated poisons like this without safety equipment and a nicotine assay kit to determine the final mix strength. PG VG Nicotine Test Kit Bromothymol Blue .12N Sulfuric Acid | eBay You should not be doing this in any case unless you have some background knowledge, and know how to work safely with poisons. When the vendor is obviously incompetent, you are in real danger unless you know how to work safely and test the materials. update 2011-11-16 The materials were tested by a chemist and found to be incorrectly labelled, varying from 48% to 272% of the marked strength. No tests for contamination were performed. This material should be avoided as it is not of merchantable quality. Do not DIY unless you understand the consequences and and can carry out your own testing, as it appears that some vendors are not familiar with how to test their products.