[How to validate a bio-analytical method].

It is imperative that any newly established bio-analytical method is validated thoroughly, using standardised parameters. The purpose of this article is to provide recommendations on how to validate a new bio-analytical method. Based on author's personal experience and some interesting discussion points from the conference of "International Association of Forensic Toxicologists" in 2007, the authors propose these essential requirements for validating a new analytical method. The key parameters of method validation include selectivity, linearity, accuracy, precision, LOD (limit of detection), LLOQ (the lower limit of quantitation), stability and the extraction recovery. For any bio-analytical method using LC-MSn (Liquid chromatography-mass spectrometry), studies of matrix effect should also be included in addition of the above parameters.