CE 772
29 October 1997
Open Book, Open Notes
Answer any three of the following four questions:
(each is
worth 33%)
Discuss
the various steps in preparing and atomizing a sample for analysis by graphite
furnace atomic absorption spectrophotometry.
Summarize
the types of errors that can be encountered in UV-Vis spectrophotometry. Explain why there exists an optimal range
for molecular absorption measurements.
Describe
three different schemes for distinguishing organic from inorganic carbon using
a modern TOC analyzer. Comment on their
relative merits.
You
have made the following measurements using electrothermal AA. These are replicate analyses of the same
sample, filtered and unfiltered. The
values are in units of µg/L. Determine
the mean and standard deviation of the particulate iron concentration for this
sample.
Replicate # |
1 |
2 |
3 |
Total Iron |
55.6 |
53.4 |
57.2 |
Dissolved Iron |
50.3 |
51.1 |
52.4 |