Here at Alkemists Labs, we get a ton of questions sent every week to firstname.lastname@example.org on this topic and the truth of the matter is that although you start with typical Pharmacopieal methodologies (USP, JP, EP/BP, AOAC, etc), just about 9 out of 10 times, the method will need to be augmented, though recorded for repeatability purposes, due to the nature of the product/sample matrix. And by matrix I'm refering to the composition of the sample, which itself and introduce many challenges to any highly trained analyst.
So though we have a huge library and database of botanical identity methods (over 1000 now), we're constantly optimizing such methods for our clients depending on what they send us. For the whole, untouched/unextracted botanicals, analysis tends to be much simpler and consistent, but then again we get herbs and botanicals from around the world, so it's always exciting to work on new challenges. Much of what this goes to help validate is a base of experience and dated expertise that we leverage to tackle time-sensitive projects or other test requests. Most importantly, the degree of assurance and quality of work offered to Clients is what keeps them coming back. Nonetheless, the best methods for botanical identity testing are the one's developed specific to a Clients product/ingredient and presuming that the upfront investment in Development is worthwhile to them, potential downstream issues relating to product variability, ingredient sourcing, lab testing, or meeting label claims are almost certainly avoidable.
For more information check us out at http://www.alkemist.com