課程名稱︰分析化學
課程性質︰必修
課程教師︰林金全
開課學院：化學系
開課系所︰理學院
考試日期（年月日）︰05-05-08
考試時限（分鐘）：兩小時
是否需發放獎勵金：是
（如未明確表示，則不予發放）
試題 :
1. Consider the peaks for n-C7H16 and 1,4-diflurobenzene in the chromatogram
show below. The elution time for unretained solute is 1.06 min. The open
tubular column is 30.0 m in length and 0.530 min in diameter, with a layer
of stationary phaes 3.0 μm thick on the inner wall.
a). Find the adjusted retention times and capacity factors foe both
compounds.
b). Find the relative retention, α.
c). Find the seperation factor, γ.
d). Measuring W(1/2) on the chromatogram, find the number of plates, N1 and
N2, and the plate height for these two compounds.
e). Measuring the width, w, at the baseline on the chromatogram, find the
number of plates for these two compounds.
f). Use your answer to part (e) to find the resolution between the two
peaks.
g). Using the number of plates [N]=√N1N2 , with values from part (e)
and the observed seperation factor, caculate what the resolution
should be and compare your answer with the measured resolution
in part (f). 14%
2. Suppose that the acid HA (with dissociation constant Ka ) is partitioned
between aqueous phase 1 and organic phase 2. Calling the partition
coefficient K for HA and assuming that A- is not soluble in hte organic
phase.
(a). show that ths distribution coefficient is given by:
K。[H+]
D= －－－－ = K。αHA
[H+] + Ka
(b). If K = 3.0 for an amine (B) and Ka = 1.0x10^-9 for the BH+, and
if 50 ml of 0.010M aqueous amine is extracted with 100 mL of solvent,
what will be the formal concentration remaining in the aqueous
phase at pH 9.00? 16%
3. An electrospray/trasmission quadrupole mass spectrum of the α chain of
hemoglobin feom acidic solution exhibits nine molecular mass of the neutral
protein, M, from peak A,B,G,H, and I, and find the mean value. 14%
Peak mlz Amplitude Peak mlz Amplitude
A 1261.5 0.024 F not satated 1.000
B 1164.6 0.209 G 834.3 0.959
C not stated 0.528 H 797.1 0.546
D not stated 0.922 I 757.2 0.189
E not stated 0.959
4. Find the number of rings plus double bonds in molecules with the f
following composition and draw one plausible strcture for each
(a) C11H18N2O3 (b) C12H15BrNPOS；(c) a fragment in a mass spetrum
with the composition C3H5+ 12%
5. The first excited state of Ca ia reached by absorption of 422.7nm light.
(a). Find the energy difference(kJ/mol) between ground and excited states.
(b). The degeneracies are g*/g0 =3 for Ca. Find N*/N0 at 2500 K.
(c). By what percentage will N*/N0 change with a 15 K rise in temperature?
(d). Find N*/N0 at 6000 K. 16%
6. The laser atomic fluorescence excitation and emission spectrum os sodium
are in an air acetylene flame. In the excitation spectrum, the laser
(bandwidth = 0.03 nm) was scanned through various wavelengths while the
detector monochromator (bandwidth = 1.6 nm ) was held fixed near 589.0 nm.
In the emission spectrum, the laser was fixed at 589.0 nm. monochromator
wavelength was varied. Explain why the emission spectrum given one board
band, whereas the excitation spectrum given two sharp lines. How can the
excitation linewidths ba much narrower than detector monochromator
bandwidth? 12%
7.(a) How do the timeof flight mass spectrometer and ion mobility spectrometer
seperate the positive ions?
(b) Explain the method of D2 lamp background correction used in graphite
furnance atomic absoprtion measurments.
(c) Explain operation of inductively- coupled plasma(ICP) torch.
(d) Briefly describe two method for introducing eluate from liquid
chromatography into a mass spectrometer. 20%
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