Hello /sci/. I need your chemical genius insight and absolute knowledge to solve one of the biggest mysteries I recently encountered.
I made few liters of hand disinfectant. The composition of the product is secret, but I will share it with you anyway, since I trust you, /sci/. The product consist of approx. 75g/100g of denatured ethanol and approx. 2g/100g of distilled glycerol.
Now, in some of the containers, the product changed its colour to pink. The product in few other containers seems to be yellow. All the coloured fluid has a pH of 5.4 - 5.6. Product without colour change is neutral. So I neutralized the coloured fluid with weak solution of KOH and the colour disappeared. The ethanol contaminants used for the denaturation process are: MEK, IPA and t-butyl alcohol.
My question to you, /sci/, is: do you have any idea what substances present in the mixture can cause this colour change which is pH dependent? My friend checked the colour using spectrophotometer and the wavelength absorption peak is 485-495 nm.
Btw, the containers were clean and new. The cap is green. Both are made from PP. There is no rubber seal. The containers are white/ transparent.
I made few liters of hand disinfectant. The composition of the product is secret, but I will share it with you anyway, since I trust you, /sci/. The product consist of approx. 75g/100g of denatured ethanol and approx. 2g/100g of distilled glycerol.
Now, in some of the containers, the product changed its colour to pink. The product in few other containers seems to be yellow. All the coloured fluid has a pH of 5.4 - 5.6. Product without colour change is neutral. So I neutralized the coloured fluid with weak solution of KOH and the colour disappeared. The ethanol contaminants used for the denaturation process are: MEK, IPA and t-butyl alcohol.
My question to you, /sci/, is: do you have any idea what substances present in the mixture can cause this colour change which is pH dependent? My friend checked the colour using spectrophotometer and the wavelength absorption peak is 485-495 nm.
Btw, the containers were clean and new. The cap is green. Both are made from PP. There is no rubber seal. The containers are white/ transparent.
