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[求助] ICP OES 英文问题求大神解答急急急急急

In  the  table  is  presented  a  variance  analysis  for  the  determination  of  total concentration of four metals in sewage sludge. The data includes relative variances in sampling, pre-treatment by microwave assisted acid digestion by aqua regia, analysis by ICP-OES as well as measurement bias. From this a total relative uncertainty (u) was calculated.
Quantification was done by external calibration. Observe that the relative variances
are given in the table, meaning that the original standard deviation value for each
parameter (sampling, treatment and analysis) has been divided with the Mean values
given in the table. The bias has been estimated from the results for a soil certified
reference  material  in  the  following  way;  Bias2 =  ((measured  value -  certified
value)/certified value))2. In the table also the % of the total relative uncertainty is
given for each of the four contributing uncertainty sources.

a. How do you interpret these results?
(2.5p)
b. Considering the results above and the method used in this study, what would
you suggest to do to improve the total uncertainty in the analysis?
(2.5p)
c. For the determination of trace metals/metalloids in soils by ICPMS on this
course, you used a marine sediment certified reference material (MESS-3) as a
quality assurance measure. In general, the agreement between measured and
certified  analyte  concentrations  was  rather  poor.  From  your  available
experimental data it is complex to explain the exact reasons for these results.
Suggest specific experiments that could be done to try to find out the possible
reasons for the differences between measured and certified concentrations.
(5p)

table.jpg

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