Particle size and shape analysis using microscope
OBJECTIVES
To determine the size and shape of different types of particles.
PROCEDURES
1. Using a microscope , 5 different types of sands and powders (MCC, lactose) with particular emphasis on the size and shape of the particles.
2. The particles observed microscopically is sketched and the general shape for the particular material is determined. The magnification that used are noted in sketching the particles.
RESULTS
QUESTIONS
1. The various statistical method that can be used
to measure the diameter of a particle are sieve method which is extremely old
technique. The advantage of this method is cheap and readily usable for large
particles. But its disadvantage is this method not possible to measure spray
and emulsion. The equivalent diameter of this method is equivalent diameter.
Second method is microscope method which is the excellent method as it directly
look at the particles in question. But this method is not suitable for quality
control slow preparation. Next is counter counter method. It is electrical
stream sensing zone method which developed by H Coulter to measure any
particulate material that can be suspended in an electrolyte and its equivalent
diameter is volume diameter. The other method which can be used is laser light
scattering method which using a laser diffraction and dynamic light scattering
method which involved photon correlation spectroscopy.
2. The best statistical method is a microscopic method as involve the
direct with particle in contact with question.
DISCUSSION
A sieve analysis is a practice or procedure
used to assess the particle size distribution of a granular material. Dimension
of particulates are important in achieving optimum production of efficacious
medicine. Solid particles are often considered to approximate to a sphere and
can be characterized by determination of its diameter. Fine particles have
irregular and different number of faces and thus, it would be difficult or
impractical to determine more than a single dimension. There are various
methods in which particle size analysis can be carried out. Among those are,
sieve method, microscopic method, coulter counter, laser light scattering
method and dynamic light scattering method. The method used in this experiment
is the microscopic method.
The errors that usually occur in a
microscopy method are, firstly, the observation varies from person to person
due to different types of vision. Secondly, there might be chances of using a
wrong magnification during the process of obtaining the results. This is
because there are three different magnifications for a light microscope and it
totally depends on one’s choice of magnification. Thirdly, the amount of sample
placed on the slide can also affect the result of the experiment because if too
much of a sample is used, the observation would not be clear and one would be
unable to obtain a clear image until an appropriate amount of sample is used.
There are a few steps that should be taken
to overcome the errors mentioned above. For example, only one person should
observe the image under the microscope and draw the image obtained to prevent
variation in observations of one sample.
Next, to overcome the probability of using a wrong magnification, one
should always start observing a sample under a magnification of 10, followed by
40, and then 100. Other than that, one should be aware that too much amount of
a sample cannot be placed on the slide because as mentioned above, this might
affect the results obtained. Thus, a fair amount of sample should be placed on
the slide for each observation.
CONCLUSION