课程名称︰分析化学三 课程性质︰化学系五选三必修 课程教师︰何国荣 开课学院：理学院 开课系所︰化学系 考试日期（年月日）︰2013.11.08 考试时限（分钟）：120mins 是否需发放奖励金：是 （如未明确表示，则不予发放） 试题 : 下面灰色注记的字体是依最後发批改完的考卷个人认为 &助教解释重要的答题关键，不保证完全正确，仅供参考 1. Explain the standard deviation of a calibration curve can be calculated although only one analysis is performed for each standard solution. (6 points) 假设各个conc 的soln 其standard deviation相同，所以可以只测各个 soln一次来做calibration curve. signal│ ╱ (真正考卷上我一共画了5个€，代表distribution) │ € │ ╱ │ € │ ╱ │ € │╱ └────────conc 2. Explain that error is an idealized concept and errors can not be known exactly.(6 points) 因为实际上我们并不知道"真值"，所以无真正求得实验result与真值 之间的差异 3. Describe the conditoin that accuracy can not be used to estimate systemic error of a method. (6 points) accuracy 包含random/ systemic error, 测量次数不多时，random error 仍暂依定的比例，此时无法以accuracy来估计systemetic error _ _ 4. Describe the condition of using the equation μ=X±zσ/√n (6 points) 表示再测量次数有限下，但该方法的标准差是贞前经许多次量测所知道的， 故可在公式中使用σ&z 5. Explain that the between sample mean square can not be used to estimate σ(下标factor)^2 directly. (6 points) SSB除包含controled factor所造成的σ(factoe)外，也包含了random error的因素， 所以无法直接以SSB估计σ(factor)^2 6. Define the limit of detection with 5% α error (n=7) (6 points) D.F.=6时，某方法可襙到SIGNAL的最低浓度，且有1-5%的信心水准，(5%可能是伪阳) 7. For a atest of M.D.L. of 10ppb, explain that not detected can not be interpreted as less than 10 ppb. (6 points) 讲义上有图，在M.D.L.左边会被判定为not detected，此时11ppm的 sample仍有分布，所以不可以用"not detected"来宣称conc<10 8. List and describe the two major components of quality assuarance. (6 points) QA (quality assessment)：用以评估数据是否在合理范围内的方法 QC (quality control)：用以确保释数据在合理范围内的步骤(S.O.P) 9. Describe the relation between accuracy, truness, precision and type of error. (6 points) Accuracy┌random error →precision │ └systemetic error →truness/bias Accuracy: 准确度，测得result与reference value间clossness的程度，包和 random/systemetic error两部分(precision与truness) Precision:测得results间彼此clossness的程度，表示random error Truness: 许多次测量results与reference value间clossness的程度，表示 systemietic error 当high precision, high truness时，则有好的accuravy 10. Explain the contribution of Fourier Transform to 13(上标)C NMR. (6 points) 13C在天然物中含量不高，NMR讯号不强，若以FT在短时间内测量许多次，再将 结果相加转为frequency domain，即可得到较好的S/N ratio 11. Explain that the sample is often dissolved in CDCl3 or D2O in NMR experiment. (6 points) a.若是H而不是D，则会造成1H-NMR爆表的现象 b.D solvent有locking的作用，因为其δ已知，当所施加磁场改变时，我们会发现 D solvent的δ也会shift，可做及时的校正以lock祝磁场 12. Explain that NMR of higher magnetic field provide better sensitivity and better resolution. (6 points) a.较高B中能阶的splitting较大 b.H间的coupling 与B无关 13. Explain the Hubaux-Vos procedure is often not a good method to estimate L.O.D. (6 points) 因为standard deviation通常和conc相关，所以如果假设两者独立，以较高conc 时得到的σ来估计LOD则会造成误差(LOD的σ会被高估) 14. Explain the purpose of performing F test in the estimation of M.D.L (6 points) 这题如果只把流程写出来大概只会得一分，助教说众覑是要写出假设在侦测极限 附近standard deviaiotn相同，所以才用F test来看影无差异 15. Explain that the triangular instead of rectangular distribution is used to estimate the standard uncertainty of volumetric glassware. (6 points) 因为glassware volume的真正体积应该在其所标示的值得附近，亦即愈接近 x bar，其分布应愈高 16. List the three major factors of data quality. (6 points) representability:代表性 indentity:定性 accuracy:确定性→定量 17. Explain that the variance can be used to compare means more than two population. (6 points) 如果多个populations 的variance相近，其背後意义是他们可能来自同一个 更大的集合，意即他们可能有相近的mean，因此可用variance来比较多个 population mean是否相近 -- 推 jane820113:ji3 嘘 edda20047:你是饿到不会切换输入法了齁林呱呱 → jane820113:XDDDDDD 谢化咦好凶 嘘 ruby40861:还错字，版主块水桶她 → ruby40861:啊我也错字QQQQQQ --

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