Utilization of Tandem systems for the detection of impurities in radiopharmaceuticals

Abstract

In this work tandem systems were established and characterized using four cylindrical absorbers of materials with different densities for an additional quality control test. The study was performed using two secondary standard systems NPL and a homemade system composed by a well-type ionization chamber made at IPEN and a Keithley electrometer. For the establishment of the tandem systems non sealed sources were utilized. The samples with impurities were measured using combinations with different proportions of radionuclides. The ratio between the measurements with different absorbers presented constant values for each dose calibrator and pure source. The results obtained with the materials with impurities using the absorbers presented constant, but different values, depending on the impurity and its proportion in the mixture. Therefore, the use of tandem systems may be recommended for quality control programs.