I am a physician (it's been many years since my college chemistry classes) and currently working on developing a safer brand of cleaning/disinfecting wipes than the standard wipes using quaternary ammonia. I am particularly interested in using citric acid due to it's safety for humans and the environment, but also because it has been showed effective and EPA approved against many pathogens, including COVID-19.
I had been working on diluting solid food grade citric acid in distilled water at different concentrations. I started at 6% by weight and most recently went down to 0.6%. When this solution is used to clean/disinfect a surface then left to evaporate, it always leaves a whitish residue.
Is there ANYTHING that can be done to eliminate this residue? Is there another chemical I can add to the mix that will mitigate this residue?
Thank you in advance!