centrifugation 1 (1)
TRANSCRIPT
Centrifugation Faculty
Zaki Farhad HabibLecturer, Department of
Pharmaceutical Sciences, NSU
Group members
Md Samrul IslamSabbir Ahmed
Mimma Sultana ChandniReeti Sushan Roy
Faria Iqbal Mosharaf Hossain
Definition Principle of Centrifugation Classification of Centrifugation CONSTRUCTION ADVANTAGES AND DISADVANTAGES Application in industry Application in Water Treatment References
Contents
Centrifugation is a process used to separate or concentrate materials suspended in a liquid medium. The theoretical basis of this technique is the effect of gravity on particles (including macromolecules) in suspension. Two particles of different masses will settle in a tube at different rates in response to gravity.
Centrifugation
A particle,whether it is precipitate,a macromolucle or cell organelle when rotated at high speed is subjected to a centrifugal force. Centrifugal force is defined as F=mw2r Where F=intensity of centrifugal force m= effective mass of sedimenting particle w= angular velocity of rotation r = distance of migrating particles from central axis of rotation
CENTRIFUGATION:
Principle of Centrifugation
Principles of Centrifuges
Basis of Separation : Size Shape Density
Methodology:
Utilizes density difference between the particles and the medium in which these are dispersed
Dispersed systems are subjected to artificially induced gravitational fields.
The centrifugal force causes the sedimentation of heavier solid particles.
Centrifugal Force :Consider a body of mass m rotating in a circular path of radius r at a velocity v. The force acting on the body in a radial direction is given by:
F =
Here, F = centrifugal force m = mass of the body v = velocity of body r = radius of circle of rotation
mv 2r
The same body will be acted upon by a gravitational force. It can be expressed as: G = mgwhere, G = gravitational force , and g = gravitational constant
The centrifugal effect is the ratio of the two forces, so that: C = F / G = mv2 / mgr = v2 / grBut, v = 2πrn Where, n = speed of rotation.
So, F / G = (2πrn)2 / gr = 4π2r2n2 / gr = 2 π2n2d / g ……………(1)Where, d = diameter of rotation.
Continued…..
The gravitational constant has a value of 9.807 m/s2, so that equation (1) may be
simplified to:
Centrifugal effect = 2.013 n2d
Provided that , n is expressed in s-1 and d is in meter.
From the equation, it can be drawn that the centrifugal effect is proportional
directly to the diameter, but is proportional to the square of the speed of the
rotation. Thus, if it is necessary to increase the centrifugal effect, it is of greater
advantages to use a centrifuge of the same size at a higher speed, rather than use
a larger centrifuge at the same speed of rotation.
Continued…..
Classification of Centrifugation
Types of Centrifuges Centrifuges can be classified on the basis of :• speed• temperature • use
On the basis of speed:
The "speed" of a centrifuge is measured in rotation per minute, or rpm. Centrifuges are generally divided into 3 categories based on their maximum attainable speed:
Low-speed : to maximum of 5 x 103 rpm.High-speed : to maximum of 2 x 104 rpm. Ultracentrifuges : to maximum of 105 rpm.
On the basis of temperature :
Refrigerated centrifuges have a built-in refrigeration unit surrounding the rotor, with a temperature sensor and thermostat permitting selection of a particular temperature or a permissible temperature range that is maintained during centrifugation. Many biological samples are temperature sensitive, and centrifugation in the cold (1-4oC) is frequently required.
Centrifuges that are not refrigerated are normally used at whatever temperature the room they are in happens to be. This is typically described in research reports as "room temperature" or “ambient temperature”.
On the basis of use :
Centrifuges
Laboratory equipment
1. Swing-out arm type
2. Angle type3. Ultracentrifuge
Commercial equipment
Perforated bowl types
Sedimentation centrifuges
Batch1. Top driven2. Under
driven
Semi continuous
Continuous or Super centrifuge
Vertical1. Simple bowl2. Bowl with
plates
Horizontal continuous decanters
Types of Centrifugation Techniques
Density gradient centrifugation
Differential centrifugation
Ultra centrifugation
It allow separation of many or all components in a mixture and allows for measurement to be made
There are two forms of Density gradient centrifugation :
Density gradient centrifugation
Rate zonal centrifugation
Isopycnic or sedimentation equilibrium centrifugation
In Rate zonal centrifugation the solution have a density gradient. The sample has a density i.e. greater than all the layers in the solution.
The sample is applied in a thin zone at the top of the centrifuge tube on a density gradient. Under centrifugal force, the particles will begin sedimenting through the gradient
Rate zonal centrifugation
The particles will begin sedimenting in separate zones according to their size shape and density.
In this type of centrifugation ,the solution contains a greater range of densities.
The density gradient contains the whole range of densities of the particles in the sample.
Each particle will sediment only to the position in the centrifuge tube at which the gradient density is equal to its own density.
In Isopycnic centrifugation separation of particles occurs into zones on the basis of their density differences, independent of time.
Isopycnic Centrifugation:
Differential centrifugation is a common procedure in microbiology and cytology used to separate certain organelles from whole cells for further analysis of specific parts of cells.
In the process, a tissue sample is first homogenized to break the cell membranes and mix up the cell contents.
The homogenate is then subjected to repeated centrifugations, each time removing the pellet and increasing the centrifugal force.
Differential centrifugation
Ultracentrifuge The ultracentrifuge is a centrifuge optimized for spinning a rotor at very high speeds, capable of generating acceleration as high as 2 000 000 g (approx. 19 600 km/s²). There are two kinds of ultracentrifuges, the preparative and the analytical ultracentrifuge. Both classes of instruments find important uses in molecular biology , biochemistry, and polymer science.
There are different types of laboratory centrifuges:
Micro Centrifuges:Devices for small tubes from 0.2 ml to 2.0 ml (micro tubes), up to 96 well-plates, compact design, small footprint; up to 30,000 g
Clinical Centrifuges:Moderate-speed devices used for clinical applications like blood collection tubes
Multipurpose High-Speed Centrifuges:Devices for a broad range of tube sizes, high variability, big footprint
INDUSTRIAL CENTRIFUGEDefinition:
An industrial centrifuge is a machine used for fluid/particle separation.
Types:
Industrial centrifuges can be classified into two main types:
1.sedimentation centrifuge and
2. filtering centrifuges.
Sedimentation centrifuge:Sedimentation centrifuges use centrifugal force to separate solids from liquids as well as two liquids with different specific gravities.
Sedimentation centrifuges include decanter, disk-stack, solid-bowl basket and tubular bowl centrifuges.
Filtering Centrifuges:Filtering centrifuges use centrifugal force to pass a liquid through a filtration media, such as a screen or cloth while solids are captured by the filtering media. Filtering centrifuges primarily deal with perforate basket, pusher and peeler centrifuges.
TYPES:
The main parts of the Centrifuge are Bearing and Shaft, Basket, Drive and Brake BEARING AND SHAFT:The Heavy duty bearing is chosen to withstand vibratory load and centrifugal force and the shaft is made up of suitable material and duly balanced independently without the basket for higher accuracy. BASKET: The basket is made up of adequate thickness so as to withstand the loads caused by the centrifugal forces . DRIVE: The drive consists of Motor mounted at the basket casing driven through V belt with provision of the tensioning the belts. BRAKE: The Centrifuge are fitted with external shoe brakes with brake liners.
CONSTRUCTION:
Centrifuges can be used in variety of applications within the manufacturing and chemical industry.
Workshop liquids can be cleaned and be efficiently re-used by using Separator centrifuges, Examples: honing oil, quench oil, compressor oil, lube oil, hydraulic oil, wash liquids and coolants.
astewater contamination can be reduced by removal of solids (decanter) or by removing oily residues (Separator).
Sludge dewatering in a pulp and paper mill can be done more efficiently with a decanter centrifuge.
Industrial and Chemical
Advantages:• Centrifuges have a clean appearance and have little to no odour problems.• Not only is the device easy to install and fast at starting up and shutting down, but
also only requires a small area for operation. They can be selected for different applications. The machine can operate with a higher capacity than smaller machines. The device is simple to operate . Centrifuge has more process flexibility and higher levels of performance.
• Disadvantages: The machine can be very noisy and can cause vibration. The device has a high-energy consumption due to high G-forces. The decanter centrifuge has high equipment capital costs.
ADVANTAGES AND DISADVANTAGES:
Applications in Industry
Production of bulk drugs: aspirin is separated from its mother liquor by centrifugation.
Production of biological products:a) Separation of blood cells.b) Purification of insulin by selectively
precipitating other fraction of proteins.c) Separation of most of the proteinaceous drugs
and macromolecules.
Biopharmaceutical analysis of drugs:Centrifugation is used for separating the drugs which is essential for the evaluation of pharmacokinetic parameters and bioequivalence studies.
Application of Centrifuges
Evaluation of suspension and emulsion:
Centrifugation method is used as a rapid empirical test parameter for the evaluation of suspension and emulsion.
Ultracentrifugation are used for determination of molecular weight of serum albumin, insulin etc.
Isolation of bacterial cells, fungal and actinomycete mycelium and fermentation media is facilitated by laboratory centrifuge.
Removal of finely suspended solid matter (clarification) from aqueous or oily materials.
Ultracentrifuge can be used for separation of virus particles which has potential industrial applications.
IDENTIFICATION
2 mg halcinonide cream in a 50 mL centrifuge tube 15 ml water added and shaked to disperse 20 mL of chloroform added and shake for 5 minutes Cooling & Centrifugation Transfer the chloroform layer in a conical flask Repeat the process
ASSAY: Chromtography is used .
HALCINONIDE CREAM
IDENTIFICATION
centrifuge a portion of it and separate the solid by several portion of water
re crystalized from hot alcohol and crystals are used for identification
ASSAY Measured volume of oral suspension equivalent to 1 gram
sulfixazole Mixed with 40 mL of HCl and 25 mL glacial acetic acid swirl to dissolve and add 100 mL water Nitrite titration 0.1 M sodium nitrite equivalent to 26.73mg sulfisoxazole
SULFISOXAZOLE ACETYL ORAL SUSPENSION
References: 1.USP & 2. Centrifugation in biology and medical sciences by Philip Sheeler
Centrifugation
Application in Water Treatment
Separating chalk powder from water Removing fat from milk to produce skimmed
milk Separating textiles Removing water from lettuce after washing
it in a salad spinner Separating particles from an air-flow
using cyclonic separation
Other applications
The clarification and stabilization of wine Separation of water particles from clothes
while spin-drying in washing machines Separation of urine components and blood
components in forensic and research laboratory
http://trishul.sci.gu.edu.au/courses/7204BPS/Centrifugation_Lecture_2008.pdf
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http://www.ruf.rice.edu/~bioslabs/methods/fractionation/centrifugation.html
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cle/Types-of-Centrifugation-1112.html http://s3.amazonaws.com/ppt-download/cnt
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References
http://s3.amazonaws.com/ppt-download/b-150317231121-conversion gate01.ppt?response-content-disposition=attachment & Signature=jJDYNt%2F%2FdVE6sNv25yb2V0lsSxk%3D&Expires=1432267127&AWSAccessKeyId=AKIAIA7QTBOH2LDUZRTQ
http://s3.amazonaws.com/ppt-download/principlesandapplicationsofcentrifugation-140221075923-phpapp01.pptx?response-content-disposition=attachment&Signature=W%2B2TwJ7BZ7j%2B2zIC4zyW6Nh68YE%3D&Expires=1432267185&AWSAccessKeyId=AKIAIA7QTBOH2LDUZRTQ
http://www.ehow.com/list_5912175_types-rotor-centrifuges.html
References
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