The invention discloses a
water quality total
hardness and
calcium and
magnesium ion content detection method, which comprises: extracting a
water quality sample to be detected, and injecting into a
cuvette; taking a color developing
reagent, injecting the color developing
reagent into the
cuvette, blowing, stirring and uniformly mixing to obtain a reaction solution; measuring the
initial current i0 of the reaction liquid in the
cuvette at the
wavelength of 475nm and the
initial current I0 of the reaction liquid in the cuvette at the
wavelength of 640nm; then titrating, and recording a measured current value and a
titration volume while titrating; according to the obtained relation curve of the current and the
titration volume under the two wavelengths, obtaining the
titration volume corresponding to a titration judgment end point, and substituting the titration volume into the
calibration curve to obtain the concentration of total
hardness or the content of
calcium and
magnesium ions in the
water sample. The measuring method disclosed by the invention not only has extremely high
accuracy and precision, but also can be applied to measurement of total
hardness or
calcium ions under different indicators at the same time, and the
turbidity of a
water sample or
magnesium hydroxide precipitate generated during calcium
ion measurement hardly affects a test result.