Lecithin conversion and plastic bottles?

He all, I have sunflower lecithin powder. I’m using a recipe that uses equal parts distillate and lecithin by weight. I asked if I could use powder instead of liquid, and someone said yes, but there was a conversion to use powder instead of liquid, does anyone know what that would be. Also is Amazon the best place to get bulk 16oz bottles with sealable caps. Thanks all.