Assessment of the Portuguese k 0-INAA laboratory performance by evaluating internal quality control data

The Portuguese INAA laboratory processes approximately one thousand of multi-matrix samples per year, generating fifteen thousands of results in the same period, using the k (0) methodology. In order to ensure that the data produced meets the require quality any sample analysed is processed together with a reference material. Therefore, every year a large amount of results of many reference materials are generated. This work analysed a large database created with the results from the reference materials irradiated in the period 2009-2013. Zeta-scores were calculated and different control charts were created as function of the time period, irradiated mass, reference material and operator. The objective of this work was to recognise human errors, to identify deficiencies in the protocols and to improve the quality of the results generated by the laboratory.