Discussion:
Measuring Water Hardness
In an experiment for measuring water hardness in a water sample, using Atomic Absorption Spectrophotometry, I obtained a value of 173.74 ppm hardness for my water sample. Using EDTA determination, I obtained a value of 440 ppm hardness for my sample. In both these methods, I was measuring the hardness in relation specifically to Mg and Ca Ions.
Considering the fact that AA Spectrophotometry is a highly accurate method for measuring water hardness, I was wondering if there could be any possible explanations as to why the hardness for water obtained through EDTA determination is greatly larger than AA hardness. I recognize the fact human error is likely whilst carrying out an EDTA determination of a water sample.