Absorbance spectrophotometer , Physics

Assignment Help:

Absorbance spectrophotometer:

A schematic diagram of a simple instrument that is used to measure the absorption of visible light is shown in Figure below.

1116_absorbance spectrophotometer.png

When studying a compound in solution by spectrophotometry, you put it in a sample holder called a cuvette and place it in the spectrophotometer.  Light of a particular wavelength passes through the solution inside the cuvette and the amount of light transmitted (passed through the solution-Transmittance) or absorbed (Absorbance) by the solution is measured by a light meter. While a spectrophotometer can display measurements as either transmittance or absorbance, in biological applications we are usually interested in the absorbance of a given sample.

Because other compounds in a solution (or the solvent itself) may absorb the same wavelengths as the compound being analyzed, we compare the absorbance of our test solution to a reference blank.  Ideally, the reference blank should contain everything found in the sample solution except the substance you are trying to analyze or measure. For instance, in today's lab exercise you will be measuring the absorbance of a dye, bromphenol blue that was dissolved in water. The reference blank in this case would be water alone.

The amount of light transmitted through a solution is referred to as transmittance (T). The transmittance is defined as the ratio of the light energy transmitted through the sample (I) to the energy transmitted through the reference blank (I0). Since the compound being tested is not present in the reference blank, the transmittance of the reference blank is defined as 100%T.


Related Discussions:- Absorbance spectrophotometer

Find total capacity of each container, Containers in Illustrations C and D ...

Containers in Illustrations C and D are identical Each container is 3.25'w x 3.25'w  x 8.4'l Total capacity of each container 88.725 cubic feet Each container is filled wi

Velocity time, when the body is uniform motion

when the body is uniform motion

What are end-terminations, What are end-terminations? Again, we get our...

What are end-terminations? Again, we get ourselves in an area where many confusion and controversy are the order of the day. Several American institutions have tried to set sta

Illustrate what is the geocentric, Q. Illustrate What is the geocentric? ...

Q. Illustrate What is the geocentric? Answer:- It is science where the earth is the midpoint of the solar system and the other planets and the sun revolve around the earth

Evaluate types of charge, Questions: A neutral hollow metal ball is on ...

Questions: A neutral hollow metal ball is on the end of a glass rod consequently that one can move it around easily without touching the ball. A rubber rod is chafed with rabbi

Expression for the intensity distribution , Q.   Derive an expression for t...

Q.   Derive an expression for the intensity distribution due to Fraunhofer's diffraction at a single slit and shows that the intensity of the first subsidiary maxima is about 4.5 p

Interference, with the help of diagram explain the working of newton''s rin...

with the help of diagram explain the working of newton''s ring

The velocity of a body to be constant during of its motion, The velocity of...

The velocity of a body was noted to be constant during five minutes of its motion. What was acceleration during this interval its? As velocity of body remains same during given

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd