What is % purity? Different methods to determine % Purity. Determination of % purity of Organic Compound By Using DSC: •1) Polycyclic aromatic Hydrocarbons e. g Benzo[c]phenanthrene, BcPh, C18H12 •2) Ibuprofen medicine •3) Phenacetin samples at different purity ratios •4) Methamphetamine Paracetamol and Mixture of both. •5) AZT (C10H13N5O4; 3´-azido-2,3´-dideoxythymidine)

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Name Kashif Ali
Roll no. 29
Semester 1st
Section B
Class M.Phil Chemistry
School Of Chemistry
MINHAJ UNIVERSITY LAHORE (MUL)

3. “⊳ Presentation topic
Determination of % purity of Organic
Compound By Using DSC*
Presented to: Dr. Muhammad Mushtaq
Assistant Professor GCU Lahore
*Differential Scanning Calorimetry
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4. What is % purity?
⊳ % Purity indicates the amount of pure and impure
substance present in a sample.
⊳ % Purity is the percentage of the material which is
actually desired chemical in a given sample.
Note:
100% percentage purity of a chemical compound is not possible. This is due
to presence of different type of impurities (Organic impurities, inorganic
impurities etc) 4

5. Different methods to determine % Purity.
The analytical methods to be employed in examining a substance should be considered in relation to its
intended use. These analytical methods may be divided into three broad categories:
1) Those that
depend solely on an
intrinsic dynamic
property
(e.g. phase solubility
analysis and
differential scanning
Calorimetry)
2) Those that
require comparison
with an external
chemical reference
substance
(e.g. chromatographic
or
spectrophotometric
methods)
3) Other methods
UV spectrophotometry
IR spectrophotometry
Titrimetric methods.
Determination of water
and organic volatiles
Optical rotation methods
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6.  Determination of % purity of
Organic Compound By Using DSC
Some Practical examples are
give those show that % purity of
Organic compounds can be
determined with great ease
using DSC.
• 1) Polycyclic aromatic Hydrocarbons e.
g Benzo[c]phenanthrene, BcPh, C18H12
• 2) Ibuprofen medicine
• 3) Phenacetin samples at different purity
ratios
• 4) Methamphetamine Paracetamol and
Mixture of both.
• 5) AZT (C10H13N5O4; 3´-azido-2,3´-
dideoxythymidine)
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7. 1) Polycyclic aromatic Hydrocarbons e. g
Benzo[c]phenanthrene, BcPh, C18H12
“Development and validation of a differential scanning calorimetry
purity determination method for polycyclic aromatic hydrocarbons”
⊳ Article Published: Article in Accreditation and Quality
Assurance · May 2010 DOI: 10.1007/s00769-010-0632-6
Authors: 1) Vikram Kestens 2) Gert Roebben 3)Thomas P J Linsinger
Source: https://www.researchgate.net/publication/225623878
Mr (g mol-1) 228.29 Tm (K) 369.6
Purity (g g-1)l ± U(l) (k = 2) 0.9968 ± 0.0014
Inorganic impurities (g g-1) 0.0011
Compound name, abbreviation, formula and chemical
structure
Benzo[c]phenanthrene, BcPh, C18H12 7

8. 2) Ibuprofen medicine
Purity Determination and DSC Tzero
Technology
Author: R. Bruce Cassel, Ph.D.
TA Instruments, 109 Lukens Drive, New Castle
DE 19720, USA
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9. 3) Phenacetin samples at different purity ratios
The melting of a pure material takes place over an
infinitely narrow temperature range. The result is a sharp
melting spike on a DSC trace at a temperature
characteristic of that material. For a material that only has
a small amount of impurity (that dissolves in the melt, but
not in solid) the melting point is depressed and the
melting range is broadened. This is the basis of the
calorimetric purity determination by observed melting
point depression. The equations that predict the rate of
heat flow versus temperature for melting a material (of
given molecular weight, melting point, heat of fusion and
purity) are derived from thermodynamic relationships, and
predate the existence of commercial DSC’s.
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C10H13NO2
Mr 179.219g/mol
Tm 134.5*C

10. 4) Methamphetamine Paracetamol and
Mixture of both.
Evaluating the Use of Differential Scanning
Calorimetry for the Analysis of Illicit
Substances and Their Adulterants
Published : J Forensic Investigation April 2018 Vol.:6, Issue:1
© All rights are reserved by Fu et al.
Paracetamol: Pm 169 *C Mr 151.16 g/mol
Methamphetamine: Pm 140 *C Mr 149.2337gm/mol
It has been shown that DSC analysis can be used to calculate
the purity of pharmaceutical standards by utilizing melting
point depression
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11. 5) AZT (C10H13N5O4; 3´-azido-2,3´-
dideoxythymidine)
Determination of the melting temperature,
heat of fusion, and purity analysis of different
samples of zidovudine (AZT) using DSC
Article: Brazilian Journal of Pharmaceutical Sciences
vol. 46, n. 1, jan./mar., 2010
Authors: Adriano Antunes Souza Araújo1,*, Marília dos
Santos Bezerra1, Sílvia Storpirtis2, Jivaldo do Rosário Matos3
1Departament of Physiology, Federal University of Sergipe,
2Departament of Pharmacy, Faculty of Pharmaceutical
Sciences, University of São Paulo,
3Departament of Fundamental Chemistry, Institute of
Chemistry, University of São Paulo
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12. Results of differential scanning calorimetry for AZT (A sample) at different
weights.
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