High-precision measurements are possible while eliminating the influence of magnesium!
After adding the reagents to prepare the sample under specified conditions, the injection of the titrant is performed. The minimum injection volume (0.015 ml) achieved by the module's syringe driver ensures very high precision, with a maximum difference of only three drops even in two consecutive measurements using the same standard sample. Additionally, improvements in the software have accelerated the injection of the titrant in the initial stages, while slowing down the injection rate as it approaches the endpoint, ensuring even higher accuracy.
This method is a modification of the method developed by Reilly (published in Analytical Chemistry). By adjusting the pH of the solution, magnesium precipitates and is not included in the titration target. It is specialized for calcium even in the presence of large amounts of magnesium. The measurement wavelength is adjusted to the calcium–calcon (Ca–Calcon) complex, while the reference wavelength is set to the EDTA–calcon complex, allowing for accurate and reproducible detection of the endpoint.