Are analytical standards and reagents really reliable ?

Abstract : Quality assurance is one of the major challenges in analytical chemistry whatever the scope of application. The quality of analytical standards is never questioned, however sometimes odd results are obtained and all the other potential sources of discrepancies are eliminated. So, we investigated the quality of three analytical standards and reagents implemented for radiological and chemical characterizations of nuclear waste. In particular, this work examined the purity of a source of tritiated-labelled dodecane, the trueness and the purity of a DTPA reagent and the trueness of a multi-anions standard used for an intercomparison exercise. It was shown that the source of tritiated-labelled dodecane contains 60 per cent of tritiated-labelled impurities. The trueness of the DTPA concentration was questioned due to the presence of impurities in the solution. It was proven that the long-term stability of the multi-anions standard was not guaranteed for nitrite. The results clearly demonstrated that, although in opposition to intuition, cautiousness has to be taken towards the quality of the analytical standards.