Development and validation of a HS/GC-MS method for the simultaneous analysis of diacetyl and acetylpropionyl in electronic cigarette refills, Barhdadi, Sophia, Canfyn Michael, Courselle Patricia, Rogiers V., Vanhaecke T., and Deconinck Eric , J.Pharm.Biomed.Anal., 4/5/2017, Volume 142, Number 224, p.218 - 224, (2017)