Al x Ga 1− x As-GaAs heterostructures grown by liquid phase epitaxy (LPE) usually contain some aluminum in the GaAs layer. This is attributed to carryover from one growth solution to another. A procedure has been devised which, by the addition of a single step, can reduce the aluminum carryover to effectively zero. Measurements of Al content in the GaAs layer were made by low temperature absorption spectroscopy. A number of typical LPE heterostructures as well as those grown using the new technique for Al elimination were studied.