Please refer to the following link.

https://owl.oit.umass.edu/departments/Chemistry/appendix/ksp.html

Regards

I these complicated systems the solubility product concept may be inappropriate. The natural ligands on OM exchange metal ions, and the kinetics can range from fast to slow and be competitive or not.

Thanks to Professor @Bachir Achour and Professor @Paul Milham for the suggestions.

The acidic condition is indeed ideal as you have experience and we did experience the same in our geohydrological investigation around ash ponds to check potential threat to ground water. You many need to try it out with decimel pH number and freeze it, please.

thanks to Professor @ A K Shyam