The influence of pH on the ultraviolet spectra of 0.001, 0.005, and 0.010 M glyphosate, glycine, and acetic acid was investigated. Each dilution of each acid was adjusted to acidic, neutral, and basic pH values. Ultraviolet spectra were recorded from 300 to 200 nm for each acid-dilution-pH combination. The wavelength of maximum absorption (Lambdamax) of glyphosate and glycine was slightly higher in the high pH solutions than in the neutral and low pH solutions. The Lambdamax of acetic acid was apparently unaffected by changes in ph. Molar extinction coefficients (epsilon) at Lambdamax increased with pH for all three acids. Regression analysis of the absorbance versus concentration for each acid-pH combination indicated linear relationships. Coefficients of determination (r2) were greater than 0.88 at both 210 and 215 nm for all acids and pH values
McConnell, J. Scott; McConnell, Rose M.; and Hossner, Lloyd R.
"Ultraviolet Spectra of Acetic Acid, Glycine, and Glyphosate,"
Journal of the Arkansas Academy of Science: Vol. 47
, Article 19.
Available at: http://scholarworks.uark.edu/jaas/vol47/iss1/19