1. In the example shown in the text book, the average absorbence of blank was
subtracted from the adsorbence of standards in constructing a calibration
curve. Please describe the disadvantage of this approach. [5%]
2. Propose an approach to detect small systematic error. [5%]
3. If t calculate＜ t table, do we accept the null hypothesis? Why or why not?
4. Describe the reason that detection limit is often considered to be the
most important parameter in evaluation an analytical method
5. Describe the similarity and the difference between analytical sensitivity
and detection limit
6. Describe the reason that the correlation coefficient of a linear
calibration curve is often very close to 1.
7. Please explain the “detection limit” which was defined in the text book.
8. (a)Define the terms “quality assurance” “quality control” and “
quality assessment”. (b)Explain the relationship between these terms
9. Explain the usefulness of ANOVA.
10. Describe the usefulness of “quality control sample”.
11. In ANOVA, S2 between and S2 within are used in a F test .Why?
12. A 10 ml class A volumetric pipet delivers10.00± 0.03ml, if you want to
deliver 30ml of solution , should you use the same pipet or different pipets?
Why?
13. Describe the usefulness of isotope and exact mass measurement in mass
spectrometry
14. Describe the most common method for reducing the effect of random error.
15. x狰 z钋 is a correct equation but not x狰 ts . Why?
16. Please use propagation of uncertainty to explain the rule of significant
figure in multiplication and division.
17. Describe the effect of n ( number of measurements ) to the detection of
systematic error.
18. Please explain the difference between true value and population mean.
19. Please explain the purpose of calculation Sy (Sε), during the
construction of a calibration curve.
20. Describe the difference between 区accuracy and precision 参systematic
error and random error.
21. Distinguish between sensitivity and detection limit.
22. Please calculate the uncertainty of limit of detection at 95% level (σ
=1.96) if background subtraction is not used.
23. Please explain the difference between decision limit and detection limit.
24. Describe the reason that the parameter ” accuracy” is more important
than “precision”.
25. State the reason of estimating detection limit before establishing a
detection limit
26. (a). Please use the student t test to explain the purpose of a
significance test.
(b). Using a t test for detecting systematic error. We never accept the null
(H0) hypothesis .Why？
27. Explain the difference between trueness and accuracy.
28. In terms of reducing measurement error, what is the purpose of
constructing a calibration curve？
29. For a Class A 25ml pipet, the actual volume is in the range of 24.97 to
25.03ml. Please “ calculate” the uncertainty if the same pipet was used to
deliver 75ml of solution.
30. One example in the text book is used to explain the procedures of ANOVA.
(a).What is the purpose of using ANOVA in the example？
(b).What is the different between ANOVA and t test？
31. (a). List the equation for calculation the standard deviation of a
calibration curve.
(b). List the assumption that the equation in (a) can be used to calculate
the standard deviation of the signal.
32. F test is used to compare the standard deviations, explain the purpose of
using F test during the process of establishing MDL.
33. If the target allowable level is 2.0ppb and the relative standard
deviation is 20%, please calculate the level of sample which will have a 5%
rate of false positive.
34. Subtraction is often used to reduce the uncertainty due to systematic
error. Explain the price we pay for this operation.
35. Define the term detection limit ( or MDL ) and explain the difference
between detection limit and reliable detection limit.
36. Describe the assumption that detection limit can be obtained from a
calibration curve.
37. Describe and explain the two most important elements in quality assurance.
38. For a solution with pH=7.0 ± 0.1, find [H+] and its uncertainty
39. Please propose one t test example except for the one in the textbook
which is not used for detecting systematic error.
40. A student’s t test was used to determine whether the nitrogen isolated
from air has the same purity as the nitrogen obtained from chemical
decomposition of N2O. In this case, F test was not applied before the
calculation of the pooled standard deviation. Why?