Chem. 31 – 1/26 Lecture
What is Quantitative Analysis?
(and Why is it important?)
• Quantitative Analysis is the determination of a
compound’s concentration (or mass or amount)
in a sample
• Some examples of where a compound’s
concentration is important:
– level of intoxication from blood alcohol content
– determine whether a compound (e.g. F- in drinking
water) is beneficial or harmful
– risk of having health problems (such as from high LDL
concentrations or low HDL concentrations)
Roll Call
Handouts
• Syllabus
• Homework Set #1
• Laboratory Report Schedule (discussed
more in lab)
Typical Lecture Style
• Mix of white board or document camera and
powerpoint slides
• Use white board/document camera for working
out detailed problems
• Use Powerpoint slides for covering review
material (e.g. Chapter 1) or material where
having good graphics helps
• Powerpoint slides will be made available on
website
• Announcements given in first few minutes
Why is This Course Valuable?
• Analysis of chemicals is common in other
chemistry classes (e.g. Chem. 25, Chem.
125, Chem. 141, Chem. 161, etc.).
• Many of the jobs both within chemical
industry/pharmaceutical industry and in
applied areas (e.g. environmental service
and biotech) involve chemical analysis.
Research Projects
- some examples of chemical analysis
• Quantitation of glycoprotein oligosaccharides (joint with
Dr. Peavy)
protein
Oligosaccharides
from protein in
Xenopus laevis egg
glycoproteins
Glucose oligomer
standard
oligosaccharides
40
20
0
5
7.632
7.723
7.760
7.859
7.940
8.069
8.151
8.349
8.468
8.662
8.969
9.039
9.078
9.125
9.209
9.262
9.472
9.638
9.751
9.859
9.908
10
15
20
25
25.850
24.784
23.834
22.964
22.120
21.249
20.354
19.438
18.502
15.137
15.201
15.258
15.308
15.386
15.655
16.070
16.146
16.206
16.336
16.604
17.009
17.158
17.291
17.556
R
20
10.2
min
Chromatogram (each peak = 1 compound)
H3C
10
10.4
O
R'
O
H3C
H3C
10.6
O
R"
O
O
10.8
10.908
pA
10.742
FID1 B, (Y VONNE\08081301.D)
10.800
O
-
10.653
O
O
10.585
– biodiesel (on-campus
effort to use waste
fryer oil to fuel lawn
mowers)
– synthetic diesel (made
from CO + H2)
H3C
10.412
O
10.284
O
10.332
• Measurement of new
diesel fuels
10.237
1.756
1.824
14.714
180
11.263
11.334
11.386
11.435
11.509
11.669
11.733
11.813
11.864
11.975
12.324
12.356
12.404
12.454
12.527
12.809
12.856
12.965
13.277
13.315
13.369
13.417
13.490
13.810 13.764
14.206
14.259
14.314
14.364
14.439
10.742
9.573
8.269
6.764
5.013
100
4.378
4.407
4.519
4.594
4.643
4.784
4.858
5.142
5.289
5.658
6.008
6.162
6.292
6.423
6.537
6.626
6.706
6.865
6.994
7.164
80
3.244
120
10.237
10.284
10.332
10.412
10.585
10.653
10.800
10.908
60
2.143
pA
2.737
2.768
2.809
2.884
2.974
3.120
3.184
3.317
3.369
3.504
1.634
1.707
1.961
2.040
2.087
2.194
2.267
Research Projects
- some examples of chemical analysis
R
OH
O
+
+
+
11
OH
R'
O
OH
R"
O
FID1 B, (Y VONNE\08081301.D)
160
60
140
50
40
30
min
Traditional vs. Modern Methods
Characteristic
Traditional
Modern
Equipment
Glassware and balances
(low cost)
Instruments
(high cost)
Precision
High
Moderate
Speed
slow
fast
Sensitivity
low
high
Selectivity
minimal
Good to great
Chapter 1 –
Measurements and Titrations
No measurement is valuable unless it is
given with units and some measure of
uncertainty
Units – Chapter 1
Uncertainty – Chapters 3 and 4
Units of Measure
• Most Basic –
Measure
Length
Mass
Time
Temperature
Amount
SI base units (important ones)
Unit_____
meter (m)
kilogram (kg) (only one with multiplier)
second (s)
Kelvin (K)
Mole (mol)
Units of Measure
• Directly Derived from Base Units
– Volume: cube volume = l3 so units = m3
l
– Density = m/V so kg/m3
– Pressure = force(kg·m/s2)/area(m2) =
kg/(s2·m)
Units of Measure
• Other metric units (not directly in SI units)
– Density (g/cm3)
– Pressure (Pascals or Pa = kg/(s2·m))
• Non-metric units (used commonly)
– For pressure 1 atmosphere (atm) = 101300
Pa
– English/Other system (not emphasized here)
Units of Measure
• Metric
Name
Kilo
Centi
Milli
Micro
Nano
Multipliers (ones you should know)
Abbreviation Multiplier
k
x103
c
x10-2
m
x10-3
m
x10-6
n
x10-9
Analytical chemists like small quantities. An instrument that can detect 1 fg
(1 x 10-15 g) is better than an instrument that can detect 1 pg (1 x 10-12 g)