Analytic Chemistry

ANALYTICAL CHEMISTRY I
Introduction
■Definitions
■Analytical methodology
■Stages of the general analytical process
■Analytical methods: classification
■Importance of chemical analysis
DEFINITIONS OF ANALYTICAL
CHEMISTRY
• Analytical Chemistry can be defined as the science that develops

and improves methods and instruments to obtain information about the
composition and chemical nature of matter.
• Analytical Chemistry is the part of Chemistry that is interested in

knowing the composition of matter. The techniques and methods of
Analytical Chemistry allow us to know the type and quantity of the
compounds or elements found in a given sample, as well as the
distribution of the various chemical species present in it.
• It is the branch of Chemistry that aims to study the chemical
composition of a material or sample, using different methods. It is
divided into Quantitative Analytical Chemistry and Qualitative
Analytical Chemistry.
Analytical chemistry provides the methods and tools necessary
to understand our material world… to answer four basic questions
about a sample of material:
That?
Where?
How much?
What arrangement, structure or form?
K. Cammann Fresenius' J. Anal. Chem., 343 (1992):812-813
From all these definitions it is clear that ANALYTICAL CHEMISTRY “is a

Metrological Science, with a clear applied mission, aimed at solving problems,
and that from a philosophical point of view allows human beings to expand their
knowledge and vision of the world.”
DEFINITIONS
Chemical analysis is the set of operating techniques and their study,
put at the service of Analytical Chemistry.
Analytical Chemistry is the SCIENCE, chemical
analysis is the TECHNIQUE
OTHER IMPORTANT DEFINITIONS
Sample : Representative part of the material under analysis.

Analyte : Chemical species object of analysis.
Matrix: All components of a sample that are not the analytes.
Interference : Species present in the sample that makes analysis
difficult.
Technique : Medium used that provides information about the analyte
Method : Set of precise techniques and operations for the analysis of the
sample.
Identification : Confirmation of the presence of a specific substance in a
sample.
Validation : Demonstration of certainty, reliability, reproducibility and
applicability of an analytical methodology.
A sample is analyzed, an analyte is determined and one or

several physicochemical characteristics are measured.
That?
Qualitative Analytical Chemistry ( focuses on identifying the
presence or absence of an analyte)
How much? -> Quantitative Analytical Chemistry (develops methods to determine

its concentration)
ANALYTICAL METHODS
The way in which the analyte is quantified or identified allows different

types of analysis methods to be differentiated:
• Classic : they are based on chemical properties of the analyte;
gravimetric (mass) and volumetric (volume) methods.
• Instrumental s: based on chemical-physical properties; optical

(spectroscopic), electrochemical, thermal, chromatographic,
radiochemical, etc.
Signal ~ Analyte C
Pardue and Woo Í show N in this figure the
Analytical str, where Chemical Analysis E
occupies a dominant position. or
N
|
EDUCATION DEVELOPMENT
BB CHEMICAL ANALYSIS —
SELECTION
SELECTION OF HYPOTHESIS B
INTERPRETATION
OF DATA
PROBLEM <
PLANNING ASSIMILATION
OF DATA
DETERMINATION -
Sampling
Yo
Sample Treatment
Yo Yo
Physical-changes--------------------Chemical reactions
Separations -
EXTENT
Yo
Data treatment
Yo
Statistical evaluation
Stages of the analytical
process
Introduction to Analytical Chemistry
Sample Small portion, selected for your

examination of a much larger amount of material
BATC
H
GROSS SAMPLE
ANALYTICAL SAMPLE
LABORATORY SAMPLE
Unanalyzable parts
i REPRESENTATIVENESS!!
ANALYTICAL SAMPLE
ANALYTICAL PORTION
Smaller sample obtained from the raw sample by reduction processes and which must have the same
composition as this.
Explanatory table of method selection
rethinking
Definition umrimmiimimaLarmsimriminm inman maremi w iminmin
Problem
optimization
Choice of method
Treatment intake Data acquisition Treatment

•p > \ i- 1 \ pESTQQI statistical
sample sample (measurement)" data
Preliminary operations
—- ----------•
Introduction to Chemistry results
Analytics, Dr. Frine Ruiz. ANALYTICAL METHOD
https://www.academia.
SUMMARY
Method selection requires:
1. Define the analysis problem very well.
2. Take stock of the available techniques.
3. Its validation if there are no standard methods.
All operations must be optimized through operations and methods

specific to statistics.
Whatever the method chosen, some common and basic analysis
operations are almost always required:
1. Sampling.
2. Previous treatment of the sample.
3. Measurement (identification or quantification of the analyte).
4. Statistical interpretation of results.
IMPORTANCE AND APPLICATIONS
Analytical Chemistry is one of the most important branches of modern

Chemistry. It includes the separation, identification and determination of
the relative quantities of the components that make up a sample of
matter.
• In medicine, analytical chemistry is the basis of clinical laboratory tests that

help doctors diagnose illness and monitor the progress of recovery.
• In industry, analytical chemistry provides the means to test raw materials and
to ensure the quality of finished products where chemical composition is of
primary importance. To analyze household products, such as fuels, paints, drugs,
etc., procedures developed by analytical chemists are followed before selling
them to consumers.
• Environmental quality is often assessed by testing for the suspected presence
of contaminants, using analytical chemistry techniques.
• The nutritional value of foods is determined by chemical analysis of major
components, such as proteins and carbohydrates, as well as microcomponents,
such as vitamins and minerals. Even the calories of a food are often calculated
from its chemical analysis.
❖................... R.O.B.........................
Problem Analytical problem
Identification and determination of

Pollution of a river organic and inorganic contaminants
Determination of amphetamines,
“Doping” in the Olympic Games hormones, etc., in urine samples
Determination of vegetable and animal

Adulteration of olive oil with other fats
fats in the oil
Toxicity in toys Determination of Cd in yellow paints
Determination of Pb isotopic ratios in the

Age of a zircon (Th and U mineral)
mineral
GENERAL ANALYTICAL PROCESS
❖ PARAMETERS TO DEFINE IN THE ANALYTICAL PROBLEM WHAT?

ID
{ I n f orm atio n HOW MUCH? Determination

AS? Structural, surface information and spatial distribution
Nature (physical state, solubility, volatility, etc.)
• Sample Analyte concentration (sensitivity)
Matrix (interferences)
V Analysis time
V Analysis cost
V Possibility of destroying the sample
V Sample quantity available
V Means available to the analyst
V Number of analyzes (need to automate)
V Quality of results (accuracy and precision)
❖ SAMPLE TAKING
V The basic objective of the sampling program is to ensure that the sample
taken is REPRESENTATIVE of the composition of the material to be analyzed
VStages of the sampling program:
1 .-Preliminary studies
2 .-Definition of parameters to be determined
3 .-Sampling frequency and sample size
4 .- Choice of sampling points
5 .-Type of sample to analyze
6 .-Physical state of the fraction to be analyzed
7 .-Chemical properties of the material
8 .-Selection of the preparation, transportation and storage system
9 .-Reduction of the sample to an adequate size
10 .- Preparation of the sample for the laboratory
VTo the extent that the samples are homogeneous and representative, the
sampling error is reduced

❖ TRANSFORMATION OF THE ANALYTE INTO MEASURABLE FORM
1st Stage: Measurement of the quantity to be analyzed to refer the amount of
the analyte found in the analysis to the composition of the test material
2nd Stage: Dissolution
VObjectives:
■ Dissolution of the entire sample (attack and/or disintegration)
> Reagents:
• Liquids: water, acids, others
• Solids: fluxes
• Gases: air, oxygen
■ Dissolution of the analyte or matrix (leaching)
> Extractants:
• Liquids: water, acids, organic solvents
• Supercritical fluids
3rd Stage: Separation to isolate the analyte from possible interferences.
4th Stage: Preconcentration. when the concentration of the analyte in the
sample is very low.
❖ MEASUREMENT OF THE ANALYTE

V Once part of the analytical process has been completed, the final
measurement of an analytical property of the species to be determined is
reached, which will give us the real amount present in the sample.
V Any measurable property that is a function of the concentration or

quantity of the analyte serves as the basis of a method for the determination
of said component.
V Measurement constitutes a physical process performed by a measuring

instrument, any mechanism that converts a property of the system into a
useful reading.
V The measurable properties are very varied, so a wide variety of analytical
methods are available
❖ DATA PROCESSING, CALCULATIONS AND INTERPRETATION OF

RESULTS
{ OBJECTIVES OF DATA PROCESSING

■ Optimize analysis methods.
■ Check the correct functioning of the stages of the general analytical
process.
■Provide satisfactory information on the composition of the material
under analysis
{ CALCULATIONS AND INTERPRETATION OF RESULTS

■Chemometrics is currently the discipline that uses mathematical and
statistical methods, allowing greater quality in the information obtained.
■The analysis concludes when the results obtained are expressed clearly,
in such a way that they can be understood and related to the purpose of
the analysis.
❖ CHARACTERISTICS OF AN ANALYTICAL METHOD
V ACCURACY: Degree of agreement between the value obtained from the

concentration of the analyte in the sample and the true value.
V PRECISION: degree of mutual agreement between a group of results
obtained by repetitively and independently applying the same analytical
method to aliquots of the same sample.
V SENSITIVITY: ability of an analytical method to discriminate between
similar concentrations of the analyte in the sample or ability to detect
(qualitative analysis) or determine (quantitative analysis) small concentrations
of the analyte in the sample.
V SELECTIVITY: Capacity of a method to produce results that depend
exclusively on the analyte for its identification or quantification in the sample.
V ROBUSTNESS: Property of an analytical method, which describes its
resistance to change in response (result) when applied independently to
aliquots of the same sample by slightly varying the experimental conditions.
(Selects and quantifies the experimental “weak points”).
V RELIABILITY: ability of a method to maintain its accuracy and precision
over time.
ANALYTICAL METHODS
❖ CLASSIFICATIONS OF ANALYTICAL METHODS
Bibliography
GENERAL ANALYTICAL CHEMISTRY COURSE, VOLUME 1, AQUEOUS AND NON-AQUEOUS

SOLUTIONS
Gaston Charlot
Ed. Toray-masson
ANALYTIC CHEMISTRY
G.D. Christian
6th ed., McGraw-Hill, 2009
QUANTITATIVE CHEMICAL ANALYSIS

D.C. Harris
2nd ed., Reverté, 2001
QUANTITATIVE CHEMICAL ANALYSIS

G.H. Ayres
2nd ed., Harla, 1970
FUNDAMENTALS OF ANALYTICAL CHEMISTRY

GIVES Skoog, D.M. West, F.J. Holler, S.R. crouch
8th ed., Thomson, 2005
FUNDAMENTALS OF ANALYTICAL CHEMISTRY - THEORY AND EXERCISES

M. of Fr. Cañizares Macías, GA Duarte Lisci
1st ed., Faculty of Chemistry, UNAM, 2007
EQUILIBRIUM IN SOLUTION IN ANALYTICAL CHEMISTRY-THEORY, EXAMPLES AND

EXERCISES
R. Sandoval Marquez
1st ed., Faculty of Chemistry, UNAM, 2011.

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ANALYTICAL CHEMISTRY I

• Analytical Chemistry can be defined as the science that develops

• Analytical Chemistry is the part of Chemistry that is interested in

From all these definitions it is clear that ANALYTICAL CHEMISTRY “is a

OTHER IMPORTANT DEFINITIONS

Sample : Representative part of the material under analysis.

A sample is analyzed, an analyte is determined and one or

How much? -> Quantitative Analytical Chemistry (develops methods to determine

The way in which the analyte is quantified or identified allows different

• Instrumental s: based on chemical-physical properties; optical

Sample Small portion, selected for your

Treatment intake Data acquisition Treatment

All operations must be optimized through operations and methods

Analytical Chemistry is one of the most important branches of modern

• In medicine, analytical chemistry is the basis of clinical laboratory tests that

Problem Analytical problem

Identification and determination of

Determination of vegetable and animal

Toxicity in toys Determination of Cd in yellow paints

Determination of Pb isotopic ratios in the

❖ PARAMETERS TO DEFINE IN THE ANALYTICAL PROBLEM WHAT?

{ I n f orm atio n HOW MUCH? Determination

• Sample Analyte concentration (sensitivity)

GENERAL ANALYTICAL PROCESS

❖ MEASUREMENT OF THE ANALYTE

V Any measurable property that is a function of the concentration or

V Measurement constitutes a physical process performed by a measuring

GENERAL ANALYTICAL PROCESS

❖ DATA PROCESSING, CALCULATIONS AND INTERPRETATION OF

{ OBJECTIVES OF DATA PROCESSING

{ CALCULATIONS AND INTERPRETATION OF RESULTS

❖ CHARACTERISTICS OF AN ANALYTICAL METHOD

V ACCURACY: Degree of agreement between the value obtained from the

GENERAL ANALYTICAL CHEMISTRY COURSE, VOLUME 1, AQUEOUS AND NON-AQUEOUS

QUANTITATIVE CHEMICAL ANALYSIS

QUANTITATIVE CHEMICAL ANALYSIS

FUNDAMENTALS OF ANALYTICAL CHEMISTRY

FUNDAMENTALS OF ANALYTICAL CHEMISTRY - THEORY AND EXERCISES

EQUILIBRIUM IN SOLUTION IN ANALYTICAL CHEMISTRY-THEORY, EXAMPLES AND

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