The proposed method deals with an indirect procedure of determining aluminium (III) and beryllium (II) ions by means of calcium ions which are released from the insoluble calcium fluoride under certain specified conditions. Calcium ions thus liberated are determined by the Weisz ring oven technique employing glyoxal bis(o-hydroxyanil). The determination has been made selective by fixing the released calcium ions as carbonate in the ammoniacal medium, and washing the various foreign ions out of the filter paper. 0.7μg of aluminium ions and 0.3μg of beryllium ions can be determined within ±5% error.