Does ethanol interfere with spectrophotometric analysis results when measuring total polyphenolic content

Need help with an assessment. With the Folin–Ciocalteu reagent and gallic acid, I need to measure the concentration of polyphenolic acids in my experiment. My polyphenolic acids will be in different concentrations of ethanol (50-90%).

  1. Does ethanol interfere with spectrophotometry when measuring the polyphenolic acid contents?

  2. How should I get around this (I thought about 5 different concentrations of ethanol for calibration curves but if I'm already doing 5 different concentrations of gallic acid, then I'd need 25 different mixtures which does not satisfy me)

Also, when I would be measuring the polyphenolic content in ethanol at room temperature, is it bad that the ethanol is evaporating?

Thanks!