有兩題相當有疑問的 找不到人可以問 因此上來求助版上神人們>"<
每題將略贈3000p薄禮...感謝
第一題
Iron standards were made-up and their absorbances were measured.
The following results were obtained.
┌──────┬───┬───┬──────────┐
│Concen.(ppm)│ Abs. │stdev │Number of replicates│
├──────┼───┼───┼──────────┤
│ 0 │ 0.015│ 0.006│ 10 │
├──────┼───┼───┼──────────┤
│ 5 │ 0.228│ 0.008│ 6 │
├──────┼───┼───┼──────────┤
│ 10 │ 0.455│ 0.011│ 6 │
├──────┼───┼───┼──────────┤
│ 20 │ 0.912│ 0.013│ 6 │
└──────┴───┴───┴──────────┘
(a) What is the detection limit for iron?
(b) What is the calibration sensitivity?
(c) What is the analytical sensitivity at 5 ppm level?
(d) What is the limit of quantitation, LOD?
第二題
The following volumes of a solution containing 1.51 ppm Zn2+ were pipetted
into separatory funnels, each countaining 5.00 mL of an known;i.e. 0.00,
5.00, 10.00, and 15.00 mL of 1.51 ppm Zn was added to different 5 mL
portions of the same solution. Each was extracted with three 5mL aliquots
of CCl4 containing an excess of 8-hydroxyquinone. The extracts were then
diluted to 25.00 mL and their fluorescence meadured. The result were:
┌────────┬──────────┐
│Vol Std Zn2+, ml│ Fluorometer reading│
├────────┼──────────┤
│ 0.00 │ 6.08 │
├────────┼──────────┤
│ 5.00 │ 11.24 │
├────────┼──────────┤
│ 10.00 │ 15.47 │
├────────┼──────────┤
│ 15.00 │ 20.84 │
└────────┴──────────┘
Caculate the concentration of Zn in the unknown.
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