The phrase "their concentrations" is correct and can be used in written English.
For example, "The scientists studied the effects of the toxins on their concentrations in the water."
All the elements were concentrated as narrow bands oscillating their concentrations (Fig. 6b d).
Some cities have increased their concentrations of minorities.
Istanbul is a fish-lover's paradise, and several of its neighborhoods, like Yesilkoy, are known for their concentrations of fine seafood restaurants.
North American and Asian rivers are somewhat intermediate in their concentrations of these dissolved constituents.
Their concentrations during pre- and post-monsoon seasons were compared.
Their concentrations were subsequently calculated from the Eqs.
Their concentrations ranged from 0.008 to 0.4 wt.%.
That fact causes decrease of the value of their concentrations.
As the contaminants migrated downstream, their concentrations were significantly reduced.
Their concentrations range from 0.75 to 5 wt.%.
Factors and their concentrations in the MEDDMs were then identified.
