UNIT 1 - Introduction to Analytical Chemistry.pdf For Med tech students

1. UNIT 1:
The Nature
of Analytical
Chemistry

2. Outline
✔ The Role of Analytical Chemistry
✔ Quantitative Analytical Methods
✔ A Typical Quantitative Analysis
✔ An Integral Role for Chemical
Analysis: Feedback Control System

3. 1A: The Role
Of Analytical
Chemistry

4. What is
Analytical Chemistry?
1A: The Role of Analytical Chemistry
Task: Create a concept map about analytical
chemistry as a discipline and its significant
applications in households, industries, and
other disciplines, etc.
(10 mins.)

5. Analytical Chemistry
It is a measurement science
consisting of a set of powerful
ideas and methods that are
useful in all fields of science,
engineering, and medicine.
1A: The Role of Analytical Chemistry

6. 1A: The Role of Analytical Chemistry

7. 1A: The Role of Analytical Chemistry

8. 2 Types of Chemical Analysis
1A: The Role of Analytical Chemistry
Qualitative Analysis – reveals the
identity of the elements and
compounds in a sample.
Quantitative Analysis – indicates
the amount of each substance in a
sample.

9. 1A: The Role of Analytical Chemistry

10. 1A: The Role of Analytical Chemistry

11. 1B: Quantitative
Analytical
Methods

12. 1B: Quantitative Analytical Methods
Challenge: Devise ways on
how you can determine
the mass of the barium
present in a barium
chloride solution of an
unknown volume.
(10 mins.)

13. Quantitative Analytical Methods
1B: Quantitative Analytical Methods
Gravimetric Methods – determine
the mass of the analyte or some
compound chemically related to
it.

14. Quantitative Analytical Methods
1B: Quantitative Analytical Methods
Volumetric Method – measures
the volume of a solution
containing sufficient reagent to
react completely with the analyte.

15. Quantitative Analytical Methods
1B: Quantitative Analytical Methods
Electroanalytical Methods –
measure electrical properties
such as potential, current,
resistance, and quantity of
electrical charge.

16. Quantitative Analytical Methods
1B: Quantitative Analytical Methods
Spectroscopic Methods – explore
the interaction between EM
radiation and analyte atoms or
molecules or the emission of
radiation by analytes.

17. 1C: A Typical
Quantitative
Analysis

18. 1C: A Typical Quantitative Analysis
Recall: List down
the steps in
conducting a
scientific method.
Give at least one
concrete example.
(10 mins.)

19. 1C: A Typical Quantitative Analysis

20. Steps in Conducting a Quantitative Analysis
1C: A Typical Quantitative Analysis
1. Choose a Method
Considerations: required accuracy level,
number of samples, sample
complexity/components
Challenges: intuition-based, large
investment time/money

21. Steps in Conducting a Quantitative Analysis
1C: A Typical Quantitative Analysis
2. Acquire Sample (rep. sample)
Considerations: large/bulk and heterogenous -
> great effort is required to get the
representative sample
Solution: Sampling (process of collecting a
small mass of a material whose composition
accurately represents the bulk of the material
being sampled); Assay (process of determining
how much of a given sample is the material by
its indicated name)

22. Steps in Conducting a Quantitative Analysis
1C: A Typical Quantitative Analysis
3. Processing the Sample
3.1 Preparing a Lab Sample
- solid samples must be ground to decrease
size and ensure homogeneity and stored for
various lengths of time before analysis begins.
- dry sample before the start of analysis
- If liquid/gas samples, keep in sealed
containers to prevent contamination

23. Steps in Conducting a Quantitative Analysis
1C: A Typical Quantitative Analysis
3. Processing the Sample
3.2 Defining Replicate Samples
- Replication improves the quality of the
results and provides a measure of their
reliability.

24. Steps in Conducting a Quantitative Analysis
1C: A Typical Quantitative Analysis
3. Processing the Sample
3.3 Preparing Solutions: Physical & Chemical
Changes
- Dissolution

25. Steps in Conducting a Quantitative Analysis
1C: A Typical Quantitative Analysis
4. Eliminating Interferences
- Species other than the analyte that affect the
final measurement are called interferences, or
interferents.
Matrix/sample matrix – is the collection of all
the components in the sample containing an
analyte.

26. Steps in Conducting a Quantitative Analysis
1C: A Typical Quantitative Analysis
4. Eliminating Interferences
- Techniques or reactions that work for only
one analyte are said to be specific. Techniques
or reactions that apply to only a few analytes
are selective.

27. Steps in Conducting a Quantitative Analysis
1C: A Typical Quantitative Analysis
5. Calibrating and Measuring
Concentration
- All analytical results depend on the final
measurement X of a physical or chemical
property of the analyte.
- The measurement of the property X is
directly proportional to the concentration 𝑐𝐴:
𝒄𝑨 = 𝒌𝑿
where 𝑘 is a proportionality constant

28. Steps in Conducting a Quantitative Analysis
1C: A Typical Quantitative Analysis
6. Calculating Results
- Computing analyte concentrations from
experimental data is usually relatively easy,
particularly with computers.
- Computations are based on raw
experimental data collected in the
measurement step, characteristics of the
measurement instruments, and the
stoichiometry of the analytical reaction.

29. Steps in Conducting a Quantitative Analysis
1C: A Typical Quantitative Analysis
7. Evaluating Results by Estimating
Reliability
- Analytical results are complete only when
their reliability has been estimated.

30. 1D: An Integral Role for
Chemical Analysis:
Feedback Control
Systems

31. An Integral Role for Chemical Analysis
1D: An Integral Role for Chemical Analysis: Feedback Control Systems

32. Feedback Control System – refers to the
process of continuous measurement and
control.
Feedback Loop – refers to the cycle of
measurement, comparison, and control.
1D: An Integral Role for Chemical Analysis: Feedback Control Systems
An Integral Role for Chemical Analysis

33. Reference
Skoog, D.A., West, D.M., Holler, F.J.,
Crouch, S.R. (2021). Fundamentals of
Analytical Chemistry (10th ed.). Cengage
Learning.