Chemical Forums
Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: PM_me_your_R2_values on October 07, 2017, 05:50:36 PM
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Hi all,
It has been a while since I've studied polarity and charges. Our lab did capillary electrophoresis on sulphates and used malonic acid as an internal standard.
My question is, does malonic acid ionize in the solution with an anionic electrolyte? Does malonic acid have an overall charge? We used indirect method targeting anions.
Sulphate I understand to be an anion, and smaller than malonic acid, so it will migrate quicker.
Other than that, I feel like I have a firm grasp on Capillary electrophoresis - it is just a matter of characterizing the peaks caused by the matrix.
TIA
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On another related noted, I don't know why a wavelength of 214 nm was used for detection. Does this have anything to do with the absorbance of the analyte? I understand UV-cut offs of solvents, but I don't see how sulphate could be detected at a wavelength of 214 nm.
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This is around where carboxylic acids absorb (electronic absorption, there are both π -> π* and n -> π* transitions in the UV region).