INTERLABORATORY RESULTS COMPARISON OF ANALYTICAL DETERMINATION OF LEAD ( Pb ) IN PETROL AND SULPHUR ( S ) IN DIESEL

Aim of this work was to perform interlaboratory comparison of analytical results of tests to estimate proficiency for laboratories accredited according to EN ISO / IEC 17025: 2006. To make officially acceptable comparison results, provider must meet the requirements of relevant international documents such as ILAC G-13: 2000 (at the time of implementation, in the meantime has issued ISO / IEC 17043:2010). In this sense, it was necessary to do the following: Establish a quality system for provider who will plan, organize, implement PT-sheme, perform statistical processing of data and create reports on the results of PT-scheme; perform statistical analysis of results obtained from laboratories participating in the PT-scheme; make a report, comments and conclusions of the analyzed results of PT-scheme. There were participate six laboratories that analyse engine fuels. It was tested content of lead (Pb) in petrol and sulphur (S) in diesel. Statistical analysis of results obtained from the participants was done in accordance with ISO 5725-1: 1994 and ISO 5725-2: 1994. Proficiency of participants were estimated by z-score calculation, as the most frequently used parameter for results assessing.