I am a graduate student trying to identify some herbicidal compounds using TLC. My system uses Dragendorff's Reagent (potassium iodo bismuthate, Munier modification). I would like to hear from anyone with extensive experience using this reagent. In trying to make it following a textbook recipe, I am having trouble getting bismuth subnitrate to dissolve. I would be very glad to hear anyone's suggestions on this. Thank you.