Azadirachtin - This product is not specifically tested for use as an analytical standard. However, it has been used as such in published articles. Please see the link below to review an example:
https://www.sciencedirect.com/science/article/pii/S1359511305002345
Product PHL89574, an Azadirachtin primary reference standard, may be of interest. Please see the link below to review this item:
https://www.sigmaaldrich.com/US/en/product/supelco/phl89574