ORGANIC ANALYSIS
a classical way
Jiří PAZOUREK | winter term | University of Veterinary and Pharmaceutical Sciences Brno
ANALYTICAL CHEMISTRY I 3150/FAAI1

ORGANIC ANALYSIS
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•State, other physical properties
•Color
•solubility
Inorganic
chemistry
=cca 50
elements

IDENTIFICATION PROCEDURE
•1. Purification
•2. Physical appearance
•3. Physical properties (melting point, boiling point, refractive index, density….spectra )
•4. Elemental analysis
•5. Confirmation / determination of functional groups
•6. Preparation of derivatives - final identification
•7. Literature comparison
•8. ( confirmation of constitution )
•REQUIRED:  mg – g of the analyte
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• chromatography (relative method)
• combination of spectral methods: UV-VIS, IR, NMR, MS
• interpretation of results, identification with libraries, structural prediction
REQUIRED:  mg - mg of the analyte
Classical                                                   Instrumental

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CLASSICAL ANALYSIS OF ORGANIC COMPOUNDS
Compounds with an identical chemical formula
Limited number of elements:

COLOR
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PHYSICAL APPEARANCE
state
colour
mixed organic dyes, oxidable or decomposed compounds

SOLUBILITY * INTERMOLECULAR FORCES * STRUCTURE
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http://img.sparknotes.com/figures/0/07cf18f888c9c21f4b45687743b63ac3/solnform.gif

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Rules:
•Similis similibus solventur  (=like dissolves like)
Intermolecular forces
Solubility of homologues
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•
•Reactive solubility
= an ACID dissolves in a BASE  or  a BASE dissolves in an ACID
Solvents
qPolar (water)
qlow polar (ether)
qReactive
SOLUBILITY/MISCIBILITY CLASSES

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•Similis similibus solventur
•Acid-base reactions
SOLUBILITY CLASSES

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SOLUBILITY CLASSES


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SOLUBILITY CLASSES


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SOLUBILITY CLASSES


ELEMENTAL ANALYSIS
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THERMAL DECOMPOSITION
A. Lavoisier
http://www.chem.yale.edu/~chem125/125/history/Analysis/Liebiganal.html
lavoisier_jl_david

Absorbs water
Absorbs CO2
D.C. Harris, Quantitative Chemical Analysis, 6th Ed., p.691
Find the empirical formula for a 13.72 mg organic compound that produced 6.97 mg of water and 28.44
mg of carbon dioxide
COMBUSTION ANALYSIS (QUANTITATIVE ANALYSIS)

MINERALIZATION
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http://www.wellesley.edu/Chemistry/chem211lab/Orgo_Lab_Manual/Appendix/ClassificationTests
http://www.umsl.edu/~orglab/experiments/UNKEXP.html?referer=www.clickfind.com.au#Class

ELEMENTAL ANALYSIS
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BEILSTEIN TEST FOR HALOGENES
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SILVER NITRATE REACTION FOR HALOGENES
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TESTS FOR FUNCTIONAL GROUPS
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BAYER (PERMANGANATE) TEST FOR UNSATURATION
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https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcRxfwAFrBWnZBGPJqjD9W0jR4dvEka1ohk5YDz2vuFsMv_
nYIjWtg Adolf von Baeyer (1905).jpg

CHROMIC ACID (JONES) TEST FOR ALCOHOLS
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Výsledek obrázku pro jones oxidation
SIR EWART RAY HERBERT JONES
1911 — 2002

LUCAS TEST FOR ALCOHOLS
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Howard Lucas
1885—1963
Související obrázek

TOLLENS TEST FOR ALDEHYDES
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Výsledek obrázku pro tollens Tollens Bernhard.jpg

2,4-DNPH TEST FOR ALDEHYDES AND KETONES
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Výsledek obrázku pro 2,4-DNPH test

LABORATORY EXERCISE No.3
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•Moodle links - quiz
•Laboratory exercise No.3 manual
•
•
•sample A = elemental analysis
•sample B = functional analysis
•flowcharts 1/2/3

LABORATORY EXERCISE No.3
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SOURCES
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PHYSICAL PROPERTIES