Extraction tests for soil and sediment analysis

MEANS OF LABORATORY MEANS OF EXTRACTABLE CONTENTS OF TRACE 

In the frame of the interlaboratory study on single extraction for soil analysis, an example has demonstrated that it is not sufficient to use a standard protocol to achieve comparability of data, i.e. it is also necessary to strictly comply with the technical requirements of the scheme one laboratory used a reciprocating shaker instead of the recommended end-over-end shaker and obtained systematically low results the repetition of the analyses clearly showed that the error was due to this fact (Table 12.3). This 

RESULTS OF THE FIRST AND SECOND INTERLABORATORY EXERCISES (STEPS 1, 2 AND 3) ON EXTRACTABLE ELEMENTS FROM SOILS 

The table lists the mean of the laboratory means along with the standard deviation (SD) and the coefficient of variation (CV) obtained, the trace metal contents are given in mg.kg adapted from ref. [30] 

The experience has shown that, while the tests carried out on some schemes resulted in a satisfactory agreement (e.g. EDTA, DTPA, acetic acid), this was not always achieved for other procedures, which demonstrated the inadequacy (or the lack of maturity ) 

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