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

Define the period and the square root of the length, What is the relationsh...

What is the relationship among the period and the square root of the length? The graph is linear, so the period is proportional to the square root of the length of the string.

Polarisation of light, Light propagates as transverse EM rays. The magnitud...

Light propagates as transverse EM rays. The magnitude of electric field is much larger as compared to magnitude of magnetic field. We generally prefer to define light as electric f

What is maser, Q. What is Maser? Give the principle of it. 1) The term...

Q. What is Maser? Give the principle of it. 1) The term MASER for Microwave Amplification through Stimulated Emission of Radiation. 2) The working of maser is similar to th

Zeener diode, how zeener diode work as a regulator?

how zeener diode work as a regulator?

#PhysicsofVolleyball, Is there a way that you can gain potential energy and...

Is there a way that you can gain potential energy and release kentic energy in Volleyball?

State the characteristics of antennas isolated, a. Explain the following te...

a. Explain the following terms in connection with electro-magnetic waves: (i) Transverse waves (ii) Power density (iii) Wave impedance (iv) Polarization b. State the chara

By which helium is produced from hydrogen in the sun, Normal 0 ...

Normal 0 false false false EN-IN X-NONE X-NONE

Determine the applications of MOSFET, Determine the Applications of MOSFET ...

Determine the Applications of MOSFET MOSFETs can  also  be  used  for  most  applications  where JFET is used. MOSFETs have become very popular for  digital logic circuits bec

Linear acceleration, The rope shown in the figure attached hereto is wound ...

The rope shown in the figure attached hereto is wound around a cylinder of of mass 4.0 kg, radius 10cm and I=0.020kgm2 , where I is the moment of inertia about an axis along the cy

Degree of freedom of monoatomic gas, If instead of molecule, we assume a mo...

If instead of molecule, we assume a molecular of a monatomic gas, which having of a one atom, the translational motion can take place in any direction in space. Thus it can be solv

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