  The general expression for the local matrix $t(\theta)$ of a quantum chain
with the site space in any representation of su(3) is obtained. This is made by
generalizing $t(\theta)$ from the fundamental representation and imposing the
fulfillment of the Yang-Baxter equation. Then, a non-homogeneous spin chain
combining different representations of su(3) is solved by developing a method
inspired in the nested Bethe ansatz. The solution for the eigenvalues of the
trace of the monodromy matrix is given as two coupled Bethe equations. A
conjecture about the solution of a chain with the site states in different
representations of su(n) is presented. The thermodynamic limit of the ground
state is calculated.
