Technical report abstract. A rapid procedure for the preparation of very pure carrier-free Zr and Nb tracer involves the chloroform extraction of the cupferrides of Zr and Nb activities from process solutions. Zr and Nb form very stable chloroform soluble cupferrides in acid solutions (CK-993) and are separated from other fission elements almost quantitatively to yield pure mixture of Zr and Nb activity. A minimum of operations is required and the method is easily adaptable to remote control.