Published in Scientific Papers. Series A. Agronomy, Vol. LXIV, Issue 2
Written by Adriana GRIGORE, Ana Maria STĂNESCU, Traian CIOROIANU, Daniela MIHALACHE, Mariana IANCU
Organo-mineral fertilizers trade has known a significant growth in the internal market. Also, the range of products in this category has greatly diversified in the last period. In order to ensure fair competition in the fertilizer market and to protect the interests of end - users, European Regulations imposed higher requirements regarding marketing and quality control of fertilizers. Thus, it is now a formal requirement for laboratories to introduce quality assurance measures to ensure that they are capable of and are providing data of the required quality. Such measures include: accreditation based on ISO 17025 or the use of validated methods of analysis. Among several parameters, evaluation of uncertainty plays an important role in method validation. This paper presents the evaluation of uncertainty for determination of iron in organo-mineral fertilizers by means of atomic absorption spectrometry. A complex organo-mineral fertilizer was used for analysis and uncertainty sources were identified and quantified for each step of the process: weighing, dilution, equipment calibration and measuring iron concentration. Relative expanded uncertainty was 9.62% and repetability was the main component of the uncertainty budget.
[Read full article] [Citation]
