Full year results presentation

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Methods of Analysis of New Chemistry N.V.korga
onkar 09/10/2006,Nagpur
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Physico-Chemical Testing

• Pesticide Formulation

Content
Physical tests
Depend on formulation type. SL,SC,EC,WDG,SG,WP
Instrumental Methods
Titration Methods
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Titration methods

• Iodometry

An oxidation-reduction titrations for the
quantitative analysis in certain chemical
compounds, in which iodine is used as a reductant
and the iodine freed in the associated reaction
is titrated, usually in neutral or slightly acid
mediums with a standard solution of a reductant
such as sodium thiosulfate and starch solution as
indicator (it forms blue complex with iodine
molecules ). The principial reaction is the
reduction of iodine by thiosulfate I2 2 S2O32-
? S4O62- 2 I-
Iodimetry When an analyte that is a reducing
agent is titrated directly with a standard iodine
solution, the method is called "iodimetry".
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Titration methods

• Drawbacks
• Time consuming.
• Susceptible to personal errors.
• General methods -not specific to product.
• Too many variables.
• Mulitiple operations.
• Low acceptability .

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Why Modern Analytical Methods ?

• Reduction in Analysis time.
• Introduction of New big molecules.( Emamectin
• Benzoate, Azoxystrobin , Luifenuron,
  Difenthiuron,
• Thiamethoxam)
• Quantitation of Byproducts.
• Separation and Quantitation of isomers.( Chiral
• chromatography)
• Authanticity Traceability of Analytical Data.
• Wider accepatance.

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Modern Analytical Techniques

• Advantages
• Quick Methods.
• Identification and Quantitation of molecule and
  
• byproducts.
• Reliability Repeatability.
• Authanticity of data.
• Traceability of data.
• Global acceptance of data.

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Gas Chromatography.

• Separation mechanism using gas as mobile phase in
  a column with stationary phase being solid
  support or inert solid support coated with liquid
  phase. Separations is due to differentiation
  Distribution coefficients.

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Gas Chromatography

• Block Diagram of GC

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Separation in column
Retention Time time spent by a compound inside
the column
From Injection Port
To Detector
Column
From Injection Port
To Detector
Column
From Injection Port
To Detector
Column
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Gas chromatography

• Columns
• Packed columns Metal,Glass,GLT.
• Capillary Column ( WCOT) Capillary,wide
  Bore,Mega
• Bore.
• Detectors
• FID,TCD,ECD,FPD,NPD
• Injectors
• PTV,On-Column,Direct,Split-Splitless

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Gas Chromatography

• Quantitative analysis
• GC is an excellent quantitative tool for
  macro determination of various types of compound.
• However the following factors must be taken
  into account to obtain reliable quantitative
  results -
• Proper sampling and sample preparation.
• Precise sample injection
• Resolution of the mixture using the right columns
  and chromatographic conditions.
• Selecting the proper detector which has adequate
  sensibility and linearity.
• Reliable data acquisition and handling system.

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Gas chromatography

• On-Column Injection.
• In this technique needle of the syringe is
  directly introduced into the wide bore column
  such technique are suitable for the analysis of
  thermally labile sample.
• Split Injection.
• Sample is injected into a heated injection port
  that contains a deactivated glass liner. The
  sample is rapidly vaporized and only 1 to2 of
  the vapour enters the column the rest of the
  vaporized sample and large flow of carrier gas
  passes out through a split or purge valve .

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Gas Chromatography

• Splitless Injection
• In splitless injection hardware is same as the
  split injection but the split outlet remains
  closed until nearly all sample material reaches
  the column and hence it is very much suitable for
  traces level analysis.
• Direct Injection
• The bottom of the vaporizing chamber is directly
  connected to the column inlet and the sample are
  directly injected and subsequently introduced
  into the column without any split hardware
  provisions.

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Gas Chromatography

• Routine Checks
• Choose high quality low bleed septa
• Change septa regularly
• Always use high quality gas
• Use and regularly change gas filters
• Use good quality clean tubing
• Regularly check and adjust gas flows
• Periodically clean the detector
• Consider detector temperature
• Ensure correct positioning of the column to
  detector
• Do not push column into FID flame.

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Gas Chromatography

• Column can be properly maintained by-
• Do not heat until purged with oxygen free gas.
• Always note injector and detector ends.
• Always cut end of the column after passing
  through ferrule.
• Do not over heat column unnecessarily.
• Use good quality ferrules and change as needed.
• Support the column cage in the oven.
• Set correct flow rate using linear carrier gas
  velocity.

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Gas Chromatography

• Things that can deteriorate a column
• Very large volume injections.
• Dirty samples, very acidic and basic samples.
• Poor gas management.
• Over heating

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HPLC

• Insufficient volatility and thermal instability
  of compounds are mainly responsible for the
  limitation imposed on G.C. On the contrary L.C.
  does not suffer from the limitations of G.C.
  mentioned above. It is ideally suited for
  separations of non-volatile or unstable material.
• In HPLC the carrier is a liquid mobile phase
  which is not inert as in the case of GC and also
  contributes towards the separation of components
  in a test mixture.

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HPLC

• Common Problems
• Broadening of Peak Sample over load,poorcolumn
  efficiency,retention time too long.
• Changing RT -Inconsistent online mobile phase
  mixing, contamination buildup,varying column
  Temperature.
• Peak Tailing - column( silica)degradation at
  high pH and Temp.,Dead volume.
• High backpressure Salt precipitation,Microbial
  growth in column,plugged frit,inline filter or
  guard column.
• Ghost peaks Retaintion of previous injection,
  Contamination ,unknowns in sample.

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HPLC

• Noise- Detector lamp problem,dirty flow
  cell,lack of solvent mixing,bubble in
  detector,pump pulses.
• All these factors lead to bad resolution and
  incorrect area of peaks and hence wrong
  estimation of the component.

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What is Required

• Infrastructure-Laboratory equiped with modern
• analytical Instruments.
• Competency -Trained staff.
• Good laboratory practices- Sampling,Calibration
  etc.
• Traceability -Good data handling and
  documentation
• system.

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• Thank You