Results for Selenate

As stressed in the interlaboratory study, the results obtained by determining selenate by difference between total selenium content and selenite would not be accepted for certification. Indeed, although this method is quite conunonly used and acceptable for selenate determination, it does not correspond to a direct measurement of the species. 

The reference value of selenate was hence based on the results of techniques actually separating the Se species (e.g. HPLC-ICP-MS or HPLC-HGAAS), with a gravimetric confirmation (target values). The values were also confirmed by alternative techniques determining selenate by difference the mean of laboratory means were (7.7 0.7) Hg and (44.8 4.4) pg L . 

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