Nephelometry and turbidimetry are light scattering techniques used to measure particle concentration in solutions. Nephelometry measures the intensity of scattered light, while turbidimetry measures the intensity of transmitted light. Both techniques rely on the principle that light scattering is dependent on particle size, wavelength, distance of observation, particle concentration, and molecular weight. The instrumentation for both techniques includes a light source, monochromators, sample cells, and detectors. Factors like particle concentration and size can affect measurements. Nephelometry and turbidimetry have applications in water quality analysis, biochemistry, and other areas.
3. NEPHELOMETRY: IN NEPHELOMETRY THE
INTENSITY OF THE SCATTERED LIGHT IS
MEASURED!
4. TURBIDIMETRY: IN TURBIDIMETRY INTENSITY OF
TRANSMITTED LIGHT IS MEASURED!
5. LIGHT SCATTERING PHENOMENON:
LIGHT SCATTERING IS THE PHYSICAL
PHENOMINON, IT’S RESULTING FROM THE
INTRACTION OF LIGHT WITH A PARTICLE IN
SOLUTION!
THIS IS DEPENDENT ON:
-) PARTICLE SIZE
-) WAVELENTH
-) DISTANCE OF OBSERBATION
-) CONC. OF PARTICLES
-) M.W. OF PARTICLES
6. PRINCIPLE OF NEPHELOMETRY & TURBIDIMETRY:
NEPHELOMETRY: INTENSITY OF THE SCATTERED
LIGHT(Is) IS DIRECTLY PROPORTIONAL TO THE
CONC. OF THE SUSPENDED PARTICLES (C) !
( Is ∝c )
WHERE:
Is= INTENSITY OF THE SCATTERED LIGHT
C= CONC. OF THE SUSPENDED PARTICLES
7. TURBIDIMETRY: INTENSITY OF THE TRANSMITT
ED LIGHT (It) IS INVERSELY PROPORTIONAL TO
THE CONC. OF THE SUSPENDED PARTICLES!
( It ∝1/C)
where:
It= INTENSITY OF THE TRANSMITTED LIGHT
C = CONC. OF THE SUSPENDED PARTICLES
9. -)LIGHT SOURCE:
TUNGUSTEN LAMP!
MURCURY ARC LAMP!
-)MONOCHROMATORS:
-)ENTERANCE SLIT: DIFINES THE INCOMING
POLYCHROMATIC LIGHT INTO NARROW BEAM!
-)COLLIMATOR- IT COLLIMATES THE RADIATIONS
FROM THE ENTRANCE SLIT!
-)PRISM- IT DISPERSE THE RADIATIONS WITH
RESPECT TO THE COMPONENT WAVELENTH!
10. -)EXIT SLIT- IT SELECT A NEAR BAND OF
DISPERSED RADIATION!
-) SAMPLE CELL- THESE ARE ALSO CALLED
CUVETTES & THEIR SHAPE & CONC. OF MATERIAL
SEPRATELY DPENDENT ON THE ISTRUMENT!
IN NEPHELOMETRY & TURBIDIMETRY MATHODS
GLASS IS USED!
THICKNESS = 1cm
LENTH = 1-2 mm
SHAPE =
CYLINDRICAL,RACTANGULAR, OR SPECIAL CELLS
WITH FLAT BOTTEM!
11. )DETECTORS- THESE ARE DIVICES WHICH
CONVERT’S THE LIGHT ENERGY INTO THE
ELECTRICAL SIGNALS,THAT ARE DISPLAYED ON
THAT ARE DISPLAYED ON THE READOUT
DIVICES!
PHPTOMULTIPLIER TUBE DETECTOR ARE MAINLY
USED IN THE NEPHELOMETRY!
12. TURBIDIMETRY: THE INSTRUMENTATION FOR
NEPHELOMETRY & TURBIDIMETRY IS SIMILAR
ONLY THE DIFFRENCE IS WITH THE DETECTORS!
HERE WE USE THE PHOTOVOLTAIC CELL &
PHOTOTUBES!
15. FACTORS AFFECTING MEASUREMENT:
THE AMOUNT OF RADIATION REMOVED OR
DEVIATED FROM PRIMARY RADIATION BEAM
DEPENDS UPON THE FOLLOWING FACTORS-:
1)CONCENTRATION-:
-) TURBIDIMETRY-:
S = LogI/I0 = Kbc
WHERE-:
T = TRANSMITTANCE = I/I0
S = TURBIDENCE
K = TURBIDITY CONSTANT
b = PATH LENTH
c = CONC. OF SUSPENDED
MATERIAL
16. -) NEPHELOMETRY-:
Is = KsI0c
WHERE-:
Is = SCATTERED INTENSITY
Ks = EMPIRICAL CONSTANT
I0 = INCIDENT INTENSITY
c = CONC. OF SUSPENDED MATERIAl
17. 2) EFFECT OF PARTICLE SIZE ON SCATTERING-:
SIZE & SHAPE OF THE PARTICLES RESPONSIBLE
FOR THE SCATTERING!
18. APPLICATION’S OF NEPHELOMETRY &
TURBIDIMETRY-:
1)Analysis of water clearty, conc. Of ions!
2)Determination of CO2!
3)Determination of Inorganic Substances-:
Sulphuric-Barium Chloride
Ammonia-Nessler’s Reagent
Phosphorus-Strychine Molybedate
4)In Biochemical Analysis!
5)Miscellaneous-:Water Treatmen inPlant’s, in
Sewagework,Refineries, Paper Industries!
6)Determination of M.W. of High Polymer’s!
19. 7)In Oraganic Analysis Clearity of Citrus juices,
benzene In Alcohol!
8)In Drug Devlopment!
9) In Atmospheric Pollution-Smokes & fog’s!
20. *) Advantages-:
1) Very Rapid Procedure!
2)Simplicity In Measurement!
3)They Are Accurate!
*) Disadvantages-:
1) High Costly!
2) Easialy Damaged!
3) They Require High Power supply!
4) Turbidity is used for Higher Concentration!
5) Nephelometry is used for Lower conc.!
