UV/visible spectroscopy involves measuring the absorption of ultraviolet or visible light by molecules. It utilizes light in the wavelength range of 200-800 nm.
The key components of a UV-visible spectrophotometer are a light source, wavelength selector such as a monochromator, sample holder, detector, and associated electronics. Common light sources include deuterium lamps, tungsten lamps, and mercury lamps. Samples are typically held in quartz or glass cuvettes. Detectors include phototubes and photodiodes.
UV-visible spectroscopy can be used to analyze samples containing multiple components. Methods for multicomponent analysis include simultaneous equations using absorption data at two wavelengths, absorbance ratio methods
Various factor affecting vibrational frequency in IR spectroscopy.vishvajitsinh Bhati
various factor affecting vibrational frequency in IR,
• Coupled vibrations
• Fermi resonance
• Electronic effects
• Hydrogen bonding
and their examples
Various factor affecting vibrational frequency in IR spectroscopy.vishvajitsinh Bhati
various factor affecting vibrational frequency in IR,
• Coupled vibrations
• Fermi resonance
• Electronic effects
• Hydrogen bonding
and their examples
In this slide contains principle of IR spectroscopy and sampling techniques.
Presented by: R.Banuteja (Department of pharmaceutical analysis).
RIPER, anantpur.
In this slide contains Interference In Atomic Absorption Spectroscopy and applications.
Presented by: Shaik Gouse ul azam. ( department of pharmaceutical analysis.)
RIPER, anantpur.
Introduction
working principle
fragmentation process
general rules for fragmentation
general modes of fragmentation
metastable ions
isotopic peaks
applications
spectrofluorometer is the instrument for recording fluorescence emission and absorption spectra When a beam of light is incident on certain substances they emit visible light or radiations. This is known as fluorescence. Fluorescence starts immediately after the absorption of light and stops as soon as the incident light is cut off. The substances showing this phenomenon are known as flourescent substances.
INSTRUMENTAL METHODS OF ANALYSIS, B.PHARM 7TH SEM. AND FOR BSC,MSC CHEMISTRY. This is Geeta prasad kashyap (Asst. Professor), SVITS, Bilaspur (C.G) 495001
In this slide contains principle of IR spectroscopy and sampling techniques.
Presented by: R.Banuteja (Department of pharmaceutical analysis).
RIPER, anantpur.
In this slide contains Interference In Atomic Absorption Spectroscopy and applications.
Presented by: Shaik Gouse ul azam. ( department of pharmaceutical analysis.)
RIPER, anantpur.
Introduction
working principle
fragmentation process
general rules for fragmentation
general modes of fragmentation
metastable ions
isotopic peaks
applications
spectrofluorometer is the instrument for recording fluorescence emission and absorption spectra When a beam of light is incident on certain substances they emit visible light or radiations. This is known as fluorescence. Fluorescence starts immediately after the absorption of light and stops as soon as the incident light is cut off. The substances showing this phenomenon are known as flourescent substances.
INSTRUMENTAL METHODS OF ANALYSIS, B.PHARM 7TH SEM. AND FOR BSC,MSC CHEMISTRY. This is Geeta prasad kashyap (Asst. Professor), SVITS, Bilaspur (C.G) 495001
INTRODUCTION TO UV-VISIBLE SPECTROSCOPYJunaid Khan
UV-visible spectroscopy is the classical and the most reliable technique for qualitative and quantitative analysis of organic compounds. It involves detection of light absorbed by the sample and correlates it with concentration of the solute.
An electron gun generates an electron beam that is interacting with a slow-wave structure.
It sustains the oscillations by propagating a traveling wave backwards against the beam
. The generated electromagnetic wave power has its group velocity directed oppositely to the direction of motion of the electrons.
The output power is coupled out near the electron gun.
OES is the reference analysis technique for elemental analysis of solid metallic samples . that uses the light emitted of an excited element and (PMT) convert the light in an electrical signal. that can be read by the instrument computer and the software
Uv visible spectroscopy with InstrumentationSHIVANEE VYAS
It is the branch of science that deals with the study of the interaction of matter with light.
OR
It is the branch of science that deals with the study of the interaction of electromagnetic radiation with matter.
Electromagnetic radiation is energy that is propagated through free space or through a material medium in the form of electromagnetic waves, such as radio waves, visible light, and gamma rays, etc. Electromagnetic waves consist of discrete packages of energy which are called as photons.
How to Split Bills in the Odoo 17 POS ModuleCeline George
Bills have a main role in point of sale procedure. It will help to track sales, handling payments and giving receipts to customers. Bill splitting also has an important role in POS. For example, If some friends come together for dinner and if they want to divide the bill then it is possible by POS bill splitting. This slide will show how to split bills in odoo 17 POS.
How to Create Map Views in the Odoo 17 ERPCeline George
The map views are useful for providing a geographical representation of data. They allow users to visualize and analyze the data in a more intuitive manner.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
What is the purpose of the Sabbath Law in the Torah. It is interesting to compare how the context of the law shifts from Exodus to Deuteronomy. Who gets to rest, and why?
The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
For more information, visit-www.vavaclasses.com
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
1. UV / VISIBLE SPECTROSCOPY
P.SUDHA
M.Pharmacy Ist Year(Pharmaceutics)
February 22, 2014
2. Spectroscopy
It is the branch of science that deals with the study of
interaction of matter with light.
OR
It is the branch of science that deals with the study of
interaction of electromagnetic radiation with matter.
4. Electromagnetic Radiation
Electromagnetic radiation consist of discrete
packets of energy which are called as
photons.
A photon consists of an oscillating electric
field (E) & an oscillating magnetic field (M)
which are perpendicular to each other.
5.
6. Electromagnetic Radiation
Frequency (ν):
It is defined as the number of times electrical
field radiation oscillates in one second.
The unit for frequency is Hertz (Hz).
1 Hz = 1 cycle per second
Wavelength (λ):
It is the distance between two nearest parts of
the wave in the same phase i.e. distance
between two nearest crest or troughs.
7. Electromagnetic Radiation
The relationship between wavelength &
frequency can be written as:
c=νλ
As photon is subjected to energy, so
E=hν=hc/λ
11. Principles of Spectroscopy
The principle is based on the measurement
of spectrum of a sample containing atoms /
molecules.
Spectrum is a graph of intensity of absorbed
or emitted radiation by sample verses
frequency (ν) or wavelength (λ).
Spectrometer is an instrument design to
measure the spectrum of a compound.
12. Principles of Spectroscopy
1. Absorption Spectroscopy:
An analytical technique which concerns with
the measurement of absorption
electromagnetic radiation.
of
e.g. UV (185 - 400 nm) / Visible (400 - 800
nm) Spectroscopy, IR Spectroscopy (0.76 - 15
μm)
13. Principles of Spectroscopy
2. Emission Spectroscopy:
An analytical technique in which emission
(of a particle or radiation) is dispersed
according to some property of the
emission & the amount of dispersion is
measured.
e.g. Mass Spectroscopy
15. Interaction of EMR with matter
1.Electronic Energy Levels:
At room temperature the molecules are in the lowest energy
levels E0.
When the molecules absorb UV-visible light from EMR, one
of the outermost bond / lone pair electron is promoted to
higher energy state such as E1, E2, …En, etc is called as
electronic transition and the difference is as:
∆E = h ν = En - E0 where (n = 1, 2, 3, … etc)
∆E = 35 to 71 kcal/mole
16. Interaction of EMR with matter
2.Vibrational Energy Levels:
These are less energy level than electronic energy levels.
The spacing between energy levels are relatively small i.e.
0.01 to 10 kcal/mole.
e.g. when IR radiation is absorbed, molecules are excited from
one vibrational level to another or it vibrates with higher
amplitude.
3. Rotational Energy Levels:
These energy levels are quantized & discrete.
The spacing between energy levels are even smaller than
vibrational energy levels.
∆Erotational < ∆Evibrational < ∆Eelectronic
18. Beer Lamberts Law:
A=εbc
A=absorbance
ε =molar absorbtivity with units of L /mol.cm
b=path length of the sample (cuvette)
c =Concentration of the compound in solution,
expressed in mol /L
20. The possible electronic transitions are
1
• σ → σ* transition
2
• π → π* transition
3
• n → σ* transition
4
• n → π* transition
5
• σ → π* transition
6
• π → σ* transition
21. 1
• σ → σ* transition
• σ electron from orbital is excited to
corresponding anti-bonding orbital σ*.
• The energy required is large for this
transition.
• e.g. Methane (CH4) has C-H bond only and
can undergo σ → σ* transition and shows
absorbance maxima at 125 nm.
22. 2
• π → π* transition
• π electron in a bonding orbital is excited to
corresponding anti-bonding orbital π*.
• Compounds containing multiple bonds
like alkenes, alkynes, carbonyl, nitriles,
aromatic compounds, etc undergo π → π*
transitions.
e.g. Alkenes generally absorb in the
region 170 to 205 nm.
23. 3
• n → σ* transition
• Saturated compounds containing atoms
with lone pair of electrons like O, N, S and
halogens are capable of n → σ* transition.
• These transitions usually requires less
energy than σ → σ* transitions.
• The number of organic functional groups
with n → σ* peaks in UV region is small
(150 – 250 nm).
24. 4
• n → π* transition
• An electron from non-bonding orbital is
promoted to anti-bonding π* orbital.
• Compounds containing double bond
involving hetero atoms (C=O, C≡N, N=O)
undergo such transitions.
• n → π* transitions require minimum
energy and show absorption at longer
wavelength around 300 nm.
25. 5
&
• σ → π* transition
• π → σ* transition
6
• These electronic transitions are forbidden
transitions & are only theoretically possible.
• Thus, n → π* & π → π* electronic
transitions show absorption in region above
200 nm which is accessible to UV-visible
spectrophotometer.
• The UV spectrum is of only a few broad of
absorption.
28. Chromophore
The part of a molecule responsible for imparting color,
are called as chromospheres.
OR
The functional groups containing multiple bonds
capable of absorbing radiations above 200 nm due to n
→ π* & π → π* transitions.
e.g. NO2, N=O, C=O, C=N, C≡N, C=C, C=S, etc
29. Auxochrome
The functional groups attached to a chromophore which
modifies the ability of the chromophore to absorb light ,
altering the wavelength or intensity of absorption.
OR
The functional group with non-bonding electrons that
does not absorb radiation in near UV region but when
attached to a chromophore alters the wavelength &
intensity of absorption.
33. 1 • Bathochromic Shift (Red Shift)
• When absorption maxima (λmax) of a
compound shifts to longer wavelength, it is
known as bathochromic shift or red shift.
• The effect is due to presence of an
auxochrome or by the change of solvent.
• e.g. An auxochrome group like –OH, -OCH3
causes absorption of compound at longer
wavelength.
34. 1 • Bathochromic Shift (Red Shift)
• In alkaline medium, p-nitrophenol shows
red shift. Because negatively charged oxygen
delocalizes more effectively than the
unshared pair of electron.
O
+
O
-
O
N
+
O
-
N
OH
-
Alkaline
OH
medium
p-nitrophenol
λmax = 255 nm
O
-
λmax = 265 nm
35. 2 • Hypsochromic Shift (Blue Shift)
• When absorption maxima (λmax) of a
compound shifts to shorter wavelength, it is
known as hypsochromic shift or blue shift.
• The effect is due to presence of an group
causes removal of conjugation or by the
change of solvent.
36. 2 • Hypsochromic Shift (Blue Shift)
• Aniline shows blue shift in acidic medium, it
loses conjugation.
NH2
+
+
H
NH 3 Cl
-
Acidic
medium
Aniline
λmax = 280 nm
λmax = 265 nm
37. 3 • Hyperchromic Effect
• When absorption intensity (ε) of a
compound is increased, it is known as
hyperchromic shift.
• If auxochrome introduces to the compound,
the intensity of absorption increases.
N
Pyridine
λmax = 257 nm
ε = 2750
N
CH3
2methylpyridine
λmax = 260 nm
ε = 3560
38. 4
• Hypochromic Effect
• When absorption intensity (ε) of a
compound is decreased, it is known as
hypochromic shift.
CH3
Naphthalene
naphthalene
ε = 19000
2-methyl
ε = 10250
41. Principle
The UV radiation region extends from 10 nm to 400
nm and the visible radiation region extends from 400
nm to 800 nm.
Near UV Region: 200 nm to 400 nm
Far UV Region: below 200 nm
Far UV spectroscopy is studied under vacuum
condition.
The common solvent used for preparing sample to be
analyzed is either ethyl alcohol or hexane.
44. Five Basic Optical Instrument Components
1) Source – A stable source of radiant energy at the desired
wavelength (or
range).
2) Wavelength Selector – A device that isolates a restricted
region of the EM spectrum used for measurement
(monochromators, prisms & filters).
3) Sample Container – A transparent container used to
hold the sample (cells, cuvettes, etc).
4) Detector/Photoelectric Transducer – Converts the
radiant energy into a useable signal (usually electrical).
5) Signal Processor & Readout – Amplifies or attenuates the
transduced signal and sends it to a readout device as a
meter, digital readout, chart recorder, computer, etc.
47. LIGHT SOURCES
Various UV radiation sources are as follows
a. Deuterium lamp
b. Hydrogen lamp
c. Tungsten lamp
d. Xenon discharge lamp
e. Mercury arc lamp
Various Visible radiation sources are as follow
a. Tungsten lamp
b. Mercury vapour lamp
c. Carbonone lamp
48. Wavelength Selectors
Wavelength selectors output a limited, narrow,
continuous group of wavelengths called a band.
Two types of wavelength selectors:
A) Filters
B) Monochromators
A)Filters –
Two types of filters:
a) Interference Filters
b) Absorption Filters
49. Cont..
B. Monochromators
Wavelength selector that can continuously scan a
broad range of wavelengths.
Used in most scanning spectrometers including UV,
visible, and IR instruments.
Refractive type
PRISM TYPE
Reflective type
Diffraction type
GRATING TYPE
Transmission Type
50. SAMPLE COMPARTMENT
Spectroscopy requires all materials in the beam path other than
the analyte should be as transparent to the radiation as possible.
The geometries of all components in the system should be such
as to maximize the signal and minimize the scattered light.
The material from which a sample cuvette is fabricated controls
the optical window that can be used.
Some typical materials are:
Optical Glass - 335 - 2500 nm
Special Optical Glass – 320 - 2500 nm
Quartz (Infrared) – 220 - 3800 nm
Quartz (Far-UV) – 170 - 2700 nm
51. Detectors
After the light has passed through the sample, we want to
be able to detect and measure the resulting light.
These types of detectors come in the form of transducers
that are able to take energy from light and convert it into
an electrical signal that can be recorded, and if necessary,
amplified.
Three common types of detectors are used
Barrier layer cells
Photo emissive cell detector
Photomultiplier
52. SUMMARY
Types of source, sample holder and detector for
various EM region
REGION
SOURCE
SAMPLE
HOLDER
DETECTOR
Ultraviolet
Deuterium lamp
Quartz/Fused
silica
Phototube, PM
tube, diode array
Visible
Tungsten lamp
Glass/Quartz
Phototube, PM
tube, diode array
54. (a) Simultaneous equation method:
If a sample contains two absorbing drugs (X and Y) each of
which absorbs at the λ-max of the other (λ1 and λ2), it may
be possible to determine both the drugs by the
simultaneous equations method.
55. The information required is
The absorptivities of X at λ1 and λ2, aX1 and aX2.
The absorptivities of Y at λ1 and λ2, aY1 and aY2.
The absorbances of the diluted sample at λ1 and λ2, A1 and
A2.
Let, Cx and Cy be the concentration of X and Y
respectively in the sample.
The absorbance of the mixture is the sum of the individual
absorbances of X and Y
56. At λ1 A1 = aX1* Cx + aY1* Cy …………..(1)
At λ2 A2 = aX2* Cx + aY2* Cy …………..(2)
Multiply the equation (1) with aX2 and (2) with aX1
A1 aX2 = aX1 Cx aX2 + aY1 Cy aX2 …………(3)
A2 aX1 = aX2 Cx aX1+ aY2 Cy aX1 ………….(4)
A1 aX2 - A2 aX1 = aY1 Cy aX2 - aY2 Cy aX1
A1 aX2 - A2 aX1 = Cy (aY1 aX2 - aY2 aX1)
Cy = (A1 aX2 - A2 aX1) / (aY1 aX2 - aY2 aX1) ……….(5)
Same way we can derive
Cx = (A2 aY1 – A1 aY2) / (aY1 aX2 - aY2 aX1)………... (6)
These equations are known as simultaneous equations and by solving
these simultaneous equations we can determine the concentration of X
and Y in the sample.
57. (b) Absorbance ratio method:
The absorbance ratio method is a
modification of the simultaneous equations procedure.
In the quantitative assay of two components in
admixture by the absorbance ratio method, absorbances
are measured at two wavelengths, one being the λ-max of
one of the components (λ2) and other being a wavelength
of equal absorptivity of two components (λ1), i.e. an isoabsorptive point.
58. At λ1
A1 = aX1* Cx + aY1* Cy …………… (1)
At λ2 A2 = aX2* Cx + aY2* Cy…………....(2)
Now divide (2) with (1)
A2/A1 = (aX2* Cx + aY2* Cy)/(aX1* Cx + aY1* Cy)
Divide each term with (Cx + Cy)
A2/A1 = (aX2* Cx + aY2* Cy) / (Cx + Cy) (aX1* Cx + aY1* Cy) / (Cx + Cy)
Put Fx = Cx / (Cx + Cy) and Fy = Cy / (Cx + Cy)
A2/A1 = [aX2 Fx + aY2 Fy] / [aX1 Fx + aY1Fy]
Where Fx is the fraction of X and Fy is the fraction of Y i.e. Fy = 1-Fx
Therefore,
A2/A1 = [aX2 Fx + aY2 (1-Fx)] / [aX1 Fx + aY1(1-Fx)]
= [aX2 Fx + aY2 – aY2Fx] / [aX1 Fx + aY1 – aY1Fx]
59. At iso-absorptive point
aX1 = aY1 and Cx = Cy
There fore
A2/A1 = [aX2 Fx + aY2 – aY2Fx] / aX1
= (aX2 Fx/ aX1) + (aY2/ aX1) –( aY2Fx/ aX1)
Let Qx = aX2/aX1 , Qy = aY2/aY1 and absorption ratio Qm = A2/A1
Qm = Fx Qx + Qy - Fx Qy
= Fx (Qx-Qy) + Qy
Fx = (Qm – Qy) / (Qx – Qy) ………………………..(3)
From the equations (1) A1 = aX1 (Cx + Cy)
there fore Cx + Cy = A1 / aX1
There fore Cx = (A1/aX1) – Cy ……………………(4)
From the equation (3)
Cx / (Cx + Cy) = (Qm – Qy) / (Qx – Qy)
There fore
Cx / (A1 / aX1) = (Qm – Qy) / (Qx – Qy)
There fore
Cx = [(Qm – Qy) / (Qx – Qy)] X (A1 / aX1) …………(5)
60. (c) Geometric correction method:
A number of mathematical correction procedures have been developed
which reduce or eliminate the background irrelevant absorption that
may be present in samples of biological origin.
The simplest of this procedure is the three point geometric procedure,
which may be applied if the irrelevant absorption is linear at the three
wavelengths selected.
61. If the wavelengths λ 1, λ 2 and λ 3 are selected to that the
background absorbances B 1 , B 2 and B 3 are linear, then
the corrected absorbance D of the drug may be calculated
from the three absorbances A 1 , A 2 and A 3 of the sample
solution at λ 1, λ 2 and λ 3 respectively as follows,
Let v D and w D be the absorbance of the drug alone in the
sample solution at λ 1 and λ 3 respectively, i.e. v and w are
the absorbance ratios vD/D and wD/D respectively.
B 1 = A 1 – vD, B 2 = A 2 –D and B 3 = A 3 –wD
62. Let y and z be the wavelengths intervals (λ 2 – λ 1 ) and
(λ 3 - λ 2 ) respectively
D= y(A 2 -A 3 ) + z(A 2 – A 1 ) / y (1-w) + z(1-v)
This is a general equation which may be applied in any
situation where A 1, A 2 and A 3 of the sample, the
wavelength intervals y and z and the absorbance ratio
v and w are known.
63. (d) Orthogonal polynomial method:
The technique of orthogonal polynomials is another
mathematical correction procedure, which involves
more complex calculations than the three-point
correction procedure. The basis of the method is that
an absorption spectrum may be represented in terms
of orthogonal functions as follows
A(λ ) = p P (λ ) + p1 P1 (λ ) + p2 P2 (λ ) ….. pn Pn (λ )
Where A denotes the absorbance at wavelength λ
belonging to a set of n+1 equally spaced wavelengths
at which the orthogonal polynomials, P (λ ) , P1 (λ ),
P2 (λ ) ….. Pn (λ ) are each defined.
64. (e)Derivative Spectroscopy:
For the purpose of spectral analysis in order to relate
chemical structure to electronic transitions, and for
analytical situations in which mixture contribute
interfering absorption, a method of manipulating the
spectral data is called derivative spectroscopy.
Derivative spectrophotometry involves the conversions of a
normal spectrum to its first, second or higher derivative
spectrum. In the context of derivative spectrophotometry,
the normal absorption spectrum is referred to as the
fundamental, zero order, or D 0 spectrum.
65.
66. The first derivative D 1 spectrum is a plot of the rate of change of
absorbance with wavelength against wavelength i.e. a plot of the slope
of the fundamental spectrum against wavelength or a plot of dA/dλ vs.
λ. . The maximum positive and maximum negative slope respectively in
the D spectrum correspond with a maximum and a minimum
respectively in the D 1 spectrum. The λmax in D spectrum is a
wavelength of zero slope and gives dA/dλ = 0 in the D 1 spectrum.
The second derivative D 2 spectrum is a plot of the curvature of the D
spectrum against wavelength or a plot of d 2 A/ dλ 2 vs. λ. The
maximum negative curvature in the D spectrum gives a minimum in
the D 2 spectrum, and the maximum positive curvature in the D
spectrum gives two small maxima called satellite bands in the D 2
spectrum. The wavelength of maximum slope and zero curvature in the
D spectrum correspond with cross-over points in the D 2 spectrum.
67. (f)Difference Spectroscopy:
Difference spectroscopy provides a sensitive method for detecting
small changes in the environment of a chromophore or it can be used
to demonstrate ionization of a chromophore leading to identification
and quantitation of various components in a mixture.
The essential feature of a difference spectrophotometric assay
is that the measured value is the difference absorbance (Δ A) between
two equimolar solutions of the analyte in different forms which exhibit
different spectral characteristics.
The criteria for applying difference spectrophotometry to the assay of a
substance in the presence of other absorbing substances are that:
A)Reproducible changes may be induced in the spectrum of the analyte
by the addition of one or more reagents.
B) The absorbance of the interfering substances is not altered by the
reagents.
68. The simplest and most commonly employed technique for altering the
spectral properties of the analyte properties of the analyte is the
adjustment of the pH by means of aqueous solutions of acid, alkali or
buffers
A
A)The Spectrum of compound in A(acid) and B(Base)
B) The difference spectrum of B relative to A
B
69. Conclusion:
Qualitative & Quantitative Analysis:
It is used for characterizing aromatic compounds and
conjugated olefins.
It can be used to find out molar concentration of the
solute under study.
Detection of impurities:
It is one of the important method to detect impurities
in organic solvents.
Detection of isomers are possible.
Determination of molecular weight using Beer’s law.
70. Reference Books
Introduction to Spectroscopy
Donald A. Pavia
Elementary Organic Spectroscopy
Y. R. Sharma
Practical Pharmaceutical Chemistry
A.H. Beckett, J.B. Stenlake
This template can be used as a starter file for presenting training materials in a group setting.SectionsRight-click on a slide to add sections. Sections can help to organize your slides or facilitate collaboration between multiple authors.NotesUse the Notes section for delivery notes or to provide additional details for the audience. View these notes in Presentation View during your presentation. Keep in mind the font size (important for accessibility, visibility, videotaping, and online production)Coordinated colors Pay particular attention to the graphs, charts, and text boxes.Consider that attendees will print in black and white or grayscale. Run a test print to make sure your colors work when printed in pure black and white and grayscale.Graphics, tables, and graphsKeep it simple: If possible, use consistent, non-distracting styles and colors.Label all graphs and tables.
Give a brief overview of the presentation. Describe the major focus of the presentation and why it is important.Introduce each of the major topics.To provide a road map for the audience, you can repeat this Overview slide throughout the presentation, highlighting the particular topic you will discuss next.
This is another option for an Overview slides using transitions.
What will the audience be able to do after this training is complete? Briefly describe each objective how the audiencewill benefit from this presentation.
This is another option for an Overview slides using transitions.
What will the audience be able to do after this training is complete? Briefly describe each objective how the audiencewill benefit from this presentation.
What will the audience be able to do after this training is complete? Briefly describe each objective how the audiencewill benefit from this presentation.
What will the audience be able to do after this training is complete? Briefly describe each objective how the audiencewill benefit from this presentation.
What will the audience be able to do after this training is complete? Briefly describe each objective how the audiencewill benefit from this presentation.
This is another option for an Overview slides using transitions.
What will the audience be able to do after this training is complete? Briefly describe each objective how the audiencewill benefit from this presentation.
What will the audience be able to do after this training is complete? Briefly describe each objective how the audiencewill benefit from this presentation.
What will the audience be able to do after this training is complete? Briefly describe each objective how the audiencewill benefit from this presentation.
What will the audience be able to do after this training is complete? Briefly describe each objective how the audiencewill benefit from this presentation.
What will the audience be able to do after this training is complete? Briefly describe each objective how the audiencewill benefit from this presentation.
This is another option for an Overview slide.
This is another option for an Overview slide.
This is another option for an Overview slide.
This is another option for an Overview slide.
This is another option for an Overview slide.
This is another option for an Overview slide.
This is another option for an Overview slide.
Add slides to each topic section as necessary, including slides with tables, graphs, and images. See next section for sampletable, graph, image, and video layouts.
Add slides to each topic section as necessary, including slides with tables, graphs, and images. See next section for sampletable, graph, image, and video layouts.
Add slides to each topic section as necessary, including slides with tables, graphs, and images. See next section for sampletable, graph, image, and video layouts.
This is another option for an Overview slide.
This is another option for an Overview slide.
This is another option for an Overview slide.
This is another option for an Overview slide.
This is another option for an Overview slide.
This is another option for an Overview slide.
This is another option for an Overview slide.
Use a section header for each of the topics, so there is a clear transition to the audience.
Give a brief overview of the presentation. Describe the major focus of the presentation and why it is important.Introduce each of the major topics.To provide a road map for the audience, you can repeat this Overview slide throughout the presentation, highlighting the particular topic you will discuss next.
Discuss outcomes of the case study or class simulation.Cover best practices.