CERTIFYING THE CONTENTS OF TRIMETHYLLEAD IN AN ARTIFICIAL RAINWATER REFERENCE MATERIAL

Certified Reference Materials are needed to verify the performance of analytical techniques used in lead speciation and for the quality cont rol of trimethyllead determinations in environmental matrices. An inte rlaboratory programme has been conducted by the Standards, Measurement s and Testing Programme to improve the state of the art of trimethylle ad determination in urban dust and artificial rainwater. This paper de scribes the preparation of an artificial rainwater reference material containing trimethyllead, its homogeneity and stability studies and th e analytical work performed for the tentative certification of the tri methyllead content at a level of approximate to 55 ng kg(-1) (as trime thyllead), While the analytical results obtained by the certifying lab oratories were considered to be suitable for certification, doubts on the long term stability of the material did not allow certification to be recommended.