INSTRUMENTAL METHOD OF ANALYSIS
1. Chromatography :-
it is defined as an analytical technique for identification and separation of components of amixture on the basis of difference in their affinity for stationary and mobile phases
- it is an excellent method for separation and identification of components
@ Adsoption chromatography :-
in this highly absorbed material is most readily adsorbed substances tend to be retained near the top and the other penetrate various distances down the column depending upon their degre from where they are absorbed
# Process of visualization of a colourless chromatogram , by spraying with a developing agent called development of chromatogram
# Advantages :-
- determining mixture that contain number of components
- In this very small quantities of substances also determined
- It also help in purifiaction of components
2. Gas chromatography :-
is a technique by which a mixture is separated into its constituents by a moving gas phase passing over a stationary adsorbent
@ Instrument used :-
i) A supply of gas crrier from high pressure cylinder having a pressure regular and flow meteres
ii) A sample injection system
iii) The separation column made from variety of material including glass, cooper steel or organic polymer like teflon about length about 0.7-2 m, while open tubular column have length between 30-300m
iv) Detector is situated at the exist of th separation column which senses and measures the small amount of separated components present in the carrier gas leaving the column
v) The recorder is fed by the output of the detector
vi) THermostated compartment fot the column and detector
#Advantages :-
- Very small amount even analysed
- It produce to raise only one pick for a components
- Gives good accuracy
# Application :-
* In analysis gasoline plant sample
* In analysis of refinary gases
* In analysis of natural gases
@ Absorption spectroscopy :-
this is a spectroscopic technique, qualitative or quantitative depending upon the measurement of an absorption spectrum
* There are some transition of electron in this are
- Electronic transition :-
electron are raised from one orbit of the constituent atom to higher orbit
- Vitrational transition :-
in this streching, contracting and bending of covalent bond take place
- Rotational transition :-
change in rotational energies of the molecule
@ Absorbance or Lambert-Beer law:-
When a monochromatic light of intensity (I) is passed through a solution of concentration ,(C) molar and thickness,(dx) then intensity of transmitted light change by (dl) . then probability of absorption of radiation is given by
dI/I=kC.dx
@ Spectroscopy:-
include study of entire radiation spectrum and its components which include their wavelength, wave number, frequency etc
# Absorption of radiatians :-
thia happen when some species brought near EMW wave and it absorbed some of its intensity
# Various intrument used to measure absorption are :-
i) calorimeter :-
it help in determination of concentration of substance by measurement of the realtive adsorption of light with respect to known concentration of substance
ii)Absorptionmeter :-
this intrument used for other spectrum length then previous one
iii) Spectrophotometer :-
this instrument mainly used in UV , visible, infrared region by using suitable source
@ Calorimetric analysis :-
this method generally for coloured solution , where their intensity of colour can easily be measured by using photoelectric calorimeter
, in this narrow beam of light passes thru the solution under test toward a sensitive photocell, light generated in photocell proportional to the amount of light transmitted by the solution, thus photocell current will be greatest when light transmitted by the solution will be greater,
@ Visible and ultra violet spectroscopy :-
absorption of UV and visible light of organic compounds involves invariably transition of valence electron
i) sigma to sigma* :-
in which a sigma bonding electron is excited to an antibonding sigma * orbital , this transition shown by only saturated hydrocarbon in which valence electron are involved in formation of sigma bonding
ii) n to Sigma* :-
This are eletronic excitation from a non bonding sigma* orbital compound having non bonding electron on heteroatom such as O,S or halogen can shown n-Sigma* transition
this transition are of lower energy and hence occur at the longer wavelength
iii) n-n* Transition :-
this are transition in which an electron in a non bonding atomi orbital is promoted to an antibonding pie* orbital
compond having double bond Double between heteroatom
Ex:- C=O, C=S, N=O
showing this type of transition appear at weak absorption bond, yhis transition require only small amount of energy and take place with in range of ordinary spectrophoto meter
iv) pie to pie* Transition :-
this transition in which a pie electron is excited to an antibonding pie* callled pie to pie* transition, they require high energy as compare to n to pie* transition
ex;- like ethylene, such as transtion take place in still for UV region
@ Chromophore :-
phenomenun by which after adding a group shows change in colour compound
or
Term, chromophore was originally used to denotee a functional group or same other structural feature , presence of which impart colour to compound
Ex:-
Nitro (No2) is chromophore , it presence in compound impart yellow colour to the compound , but this day term chromophore used in a much broad way
defined as any group which exhibite absorption of EMR in visible or UV region or may not impart any colour to compound
@ Infrared spectroscopy :-
atom in any molecule are continuely vibrating, every molecule vibrate in several way since while all molecule absorp radiation of various wavelength which can be lanmda= 1.5 to 20 micrometer in infrared region which different functional group produce easily recognisable band at nearby definite position on spectral range
# Application of IR :-
-In establishing the identity of compund
- To ascertain hydrogen bonding in a molecule
_ Provide valuable knowledge about compound
@ nuclear magnetic resonance (NMR) Spectroscopy :-
this based on fact that every atom have even or odd number of proton in centre which spin creates tiny current on placong this component in a magnetic field it align in two of one orientation from which help us to defined the structure of a molecule
* these are of many type
1. Carbon type :-
in which C type presence can be identified
2. Flourine type :-
In Which Presence of F atom can be identified and etc
# Application :-
- In identifying methanol structure which contain 3:1 ratio of CH3 and OH
_ In iidentying structure as ethanol
@ Electron spin Resonance Spectroscopy :-
this based on fact that every electron posses spin angular momemtum and by virtue of its spin it has magnetic moment
@ Raman spectra :-
molecule are either gaining or loosing energy as a result of transition between vibrational or rotational energy level called raman scattering , it is defined by formula as delta(V)= Vi-Vs , where Vi= frequency of oncident light and Vs = frequency of light scattered
# Application :-
- in determining nature of bond in diatomic molecule
_ In Determining bond in Triatomic molecule
@ Microwave spectroscopy ;-
this based on fact that transition between the rotational level og gasseous molecule possessing permanent dipole moments
@ Thermogravimetric Analysis (TGA) ;-
in this graph plotted between mass (m) versus temperatue (T) , wich provide quantitative data and qualitative data about the sample under investigation some physical and chemical changes are in as follow
- Dehydration of substance
_ Vaporization of substance
- Dissociation od substance
- Oxidation of substance
- Reduction of substance
@ Differential Thermal analysis ;-
this based on fact carefully observing and measuring heat absorbed and emitted as in chemical reaction and temperature difference occur in this during this process
@ differential Scanning Calorimetry :-
In tHis Sample with refernce sample heated continously and add some heat if sample or reference needed to maintain both temperature same
1. Chromatography :-
it is defined as an analytical technique for identification and separation of components of amixture on the basis of difference in their affinity for stationary and mobile phases
- it is an excellent method for separation and identification of components
@ Adsoption chromatography :-
in this highly absorbed material is most readily adsorbed substances tend to be retained near the top and the other penetrate various distances down the column depending upon their degre from where they are absorbed
# Process of visualization of a colourless chromatogram , by spraying with a developing agent called development of chromatogram
# Advantages :-
- determining mixture that contain number of components
- In this very small quantities of substances also determined
- It also help in purifiaction of components
2. Gas chromatography :-
is a technique by which a mixture is separated into its constituents by a moving gas phase passing over a stationary adsorbent
@ Instrument used :-
i) A supply of gas crrier from high pressure cylinder having a pressure regular and flow meteres
ii) A sample injection system
iii) The separation column made from variety of material including glass, cooper steel or organic polymer like teflon about length about 0.7-2 m, while open tubular column have length between 30-300m
iv) Detector is situated at the exist of th separation column which senses and measures the small amount of separated components present in the carrier gas leaving the column
v) The recorder is fed by the output of the detector
vi) THermostated compartment fot the column and detector
#Advantages :-
- Very small amount even analysed
- It produce to raise only one pick for a components
- Gives good accuracy
# Application :-
* In analysis gasoline plant sample
* In analysis of refinary gases
* In analysis of natural gases
@ Absorption spectroscopy :-
this is a spectroscopic technique, qualitative or quantitative depending upon the measurement of an absorption spectrum
* There are some transition of electron in this are
- Electronic transition :-
electron are raised from one orbit of the constituent atom to higher orbit
- Vitrational transition :-
in this streching, contracting and bending of covalent bond take place
- Rotational transition :-
change in rotational energies of the molecule
@ Absorbance or Lambert-Beer law:-
When a monochromatic light of intensity (I) is passed through a solution of concentration ,(C) molar and thickness,(dx) then intensity of transmitted light change by (dl) . then probability of absorption of radiation is given by
dI/I=kC.dx
@ Spectroscopy:-
include study of entire radiation spectrum and its components which include their wavelength, wave number, frequency etc
# Absorption of radiatians :-
thia happen when some species brought near EMW wave and it absorbed some of its intensity
# Various intrument used to measure absorption are :-
i) calorimeter :-
it help in determination of concentration of substance by measurement of the realtive adsorption of light with respect to known concentration of substance
ii)Absorptionmeter :-
this intrument used for other spectrum length then previous one
iii) Spectrophotometer :-
this instrument mainly used in UV , visible, infrared region by using suitable source
@ Calorimetric analysis :-
this method generally for coloured solution , where their intensity of colour can easily be measured by using photoelectric calorimeter
, in this narrow beam of light passes thru the solution under test toward a sensitive photocell, light generated in photocell proportional to the amount of light transmitted by the solution, thus photocell current will be greatest when light transmitted by the solution will be greater,
@ Visible and ultra violet spectroscopy :-
absorption of UV and visible light of organic compounds involves invariably transition of valence electron
i) sigma to sigma* :-
in which a sigma bonding electron is excited to an antibonding sigma * orbital , this transition shown by only saturated hydrocarbon in which valence electron are involved in formation of sigma bonding
ii) n to Sigma* :-
This are eletronic excitation from a non bonding sigma* orbital compound having non bonding electron on heteroatom such as O,S or halogen can shown n-Sigma* transition
this transition are of lower energy and hence occur at the longer wavelength
iii) n-n* Transition :-
this are transition in which an electron in a non bonding atomi orbital is promoted to an antibonding pie* orbital
compond having double bond Double between heteroatom
Ex:- C=O, C=S, N=O
showing this type of transition appear at weak absorption bond, yhis transition require only small amount of energy and take place with in range of ordinary spectrophoto meter
iv) pie to pie* Transition :-
this transition in which a pie electron is excited to an antibonding pie* callled pie to pie* transition, they require high energy as compare to n to pie* transition
ex;- like ethylene, such as transtion take place in still for UV region
@ Chromophore :-
phenomenun by which after adding a group shows change in colour compound
or
Term, chromophore was originally used to denotee a functional group or same other structural feature , presence of which impart colour to compound
Ex:-
Nitro (No2) is chromophore , it presence in compound impart yellow colour to the compound , but this day term chromophore used in a much broad way
defined as any group which exhibite absorption of EMR in visible or UV region or may not impart any colour to compound
@ Infrared spectroscopy :-
atom in any molecule are continuely vibrating, every molecule vibrate in several way since while all molecule absorp radiation of various wavelength which can be lanmda= 1.5 to 20 micrometer in infrared region which different functional group produce easily recognisable band at nearby definite position on spectral range
# Application of IR :-
-In establishing the identity of compund
- To ascertain hydrogen bonding in a molecule
_ Provide valuable knowledge about compound
@ nuclear magnetic resonance (NMR) Spectroscopy :-
this based on fact that every atom have even or odd number of proton in centre which spin creates tiny current on placong this component in a magnetic field it align in two of one orientation from which help us to defined the structure of a molecule
* these are of many type
1. Carbon type :-
in which C type presence can be identified
2. Flourine type :-
In Which Presence of F atom can be identified and etc
# Application :-
- In identifying methanol structure which contain 3:1 ratio of CH3 and OH
_ In iidentying structure as ethanol
@ Electron spin Resonance Spectroscopy :-
this based on fact that every electron posses spin angular momemtum and by virtue of its spin it has magnetic moment
@ Raman spectra :-
molecule are either gaining or loosing energy as a result of transition between vibrational or rotational energy level called raman scattering , it is defined by formula as delta(V)= Vi-Vs , where Vi= frequency of oncident light and Vs = frequency of light scattered
# Application :-
- in determining nature of bond in diatomic molecule
_ In Determining bond in Triatomic molecule
@ Microwave spectroscopy ;-
this based on fact that transition between the rotational level og gasseous molecule possessing permanent dipole moments
@ Thermogravimetric Analysis (TGA) ;-
in this graph plotted between mass (m) versus temperatue (T) , wich provide quantitative data and qualitative data about the sample under investigation some physical and chemical changes are in as follow
- Dehydration of substance
_ Vaporization of substance
- Dissociation od substance
- Oxidation of substance
- Reduction of substance
@ Differential Thermal analysis ;-
this based on fact carefully observing and measuring heat absorbed and emitted as in chemical reaction and temperature difference occur in this during this process
@ differential Scanning Calorimetry :-
In tHis Sample with refernce sample heated continously and add some heat if sample or reference needed to maintain both temperature same
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