|
|
 |
| |
|
|
|
Implementation of Quality Assurance System in Gamma Spectroscopy Laboratory: Best Practice for Accreditation |
|
|
|
PP: 9-21 |
|
|
|
doi:10.18576/jrna/030102
|
|
|
|
Author(s) |
|
|
|
Omar EL Samad,
Rana Baydoun,
|
|
|
|
Abstract |
|
|
| Based on ISO/IEC-17025 standards for testing and calibration laboratories, a quality assurance system was implemented at the gamma spectroscopy laboratory-at the Lebanese Atomic Energy Commission. Nowadays, routine analyses of natural and artificial gamma emitters in various matrices are performed. The laboratory has been accredited since 2012 by Hellentic Accreditation System (ESYD). All applied analytical procedures are documented. Traceability of the results has been assured through the frequent use of standards and reference materials. Method validation procedure was applied for three sets of gamma spectrometers with High Purity Germanium (HPGe) detectors. Internal validation in terms of accuracy has been achieved using various reference materials and left over proficiency test samples. The accuracy was evaluated by relative bias, repeatability and reproducibility limits, as well as precision estimator. The calculated biases for selected radionuclides were below the Maximum Acceptable Bias (MAB = 15 %). The precision estimator values were conform to the acceptance criteria, as being below acceptable limit of precision (ALP = 20 %.). The detection limit (LD) and the minimum detectable activity (MDA) were calculated according to Curie formula. Combined and expanded standard uncertainties were calculated. Quality control procedure is applied routinely; data obtained were acceptable based on Shewhart control chart rules. For external validation, the laboratory participates at least twice a year in proficiency tests. Based on the counter measure, the laboratory showed high performance, through the acceptable values of z- score that found to lie between -2 and +2.
|
|
|
|
|
|
|
|
