Metal concentration

Analytical Quality Control in Laboratories in Senegal and Mali - Analysis of Organic Contaminants and Trace Metals In this report the results of organochlorine pesticide analysis in 20 sediment samples are being discussed. These samples were analysed by the Vrije Universiteit Amsterdam and compared with the results obtained in the same samples (10) in Senegal and (10) in Mali. In addition, trace metal concentrations were analysed by Eurofins Omegam, The Netherlands, in contract for the Vrije Universiteit Amsterdam. The results show that both laboratories (Senegal and Mali) still encounter a number of barriers. One essential issue is the inability to order analytical standards when they are needed. The ordering process takes an awful lot of time, up to half a year or more. Delivery times are long, and customs can hold packages for a long time as well. Costs are also an issue as these analytical standards are quite expensive. Therefore, the laboratories often order cheaper technical standards but those are not suitable. The same is true for certified reference materials and for consumables, especially expensive consumables such as GC columns. In addition, the basic knowledge of the staff is not as good as it should be. One employee in the Mali laboratory had been on training in Europe, which made the overall impression of that laboratory better. Suggestions are given for improvement. Metal concentrations were analysed by the Senegal and Mali laboratories and compared with data from the reference laboratory. The quality of the data in both laboratories is not much better than that of the OCP analyses. As regards the environmental quality, the OCP levels do not pose an environmental or human health risk. Nickel and chromium are somewhat elevated and may need extra attention regarding human health risks.