  Given an exact category $\mathcal{C}$, we denote by $\mathcal{C}_l$ the
smallest additive subcategory containing injectives and indecomposable objects
which appear as the first term of an almost split conflation. We prove that a
deflation is right determined by some object if and only if its intrinsic
kernel lies in $\mathcal{C}_l$. We give characterizations for $\mathcal{C}$
having Auslander-Reiten duality.
