  The color anti-triplet triquark $q\bar{q}\bar{q}$ is considered as a compact
component in the tetraquark structure $cq\bar{q}\bar{q}$ of exotic $D_{s}$
mesons. We discuss the mass spectrum and the flavor mixing of the triquarks by
using the instanton induced interaction and the one-gluon exchange potentials.
As a characteristic property of the triquark, we investigate the isospin
violation. It is shown that the flavor $\bar{\bf 3}$ (isosinglet) and $\bf 6$
(isotriplet) states may be strongly mixed and then are identified with
$D_{s}(2632)$.
