Basic principles of spectrophotometry, Physics

Basic principles of spectrophotometry:

An absorbance spectrophotometer is an instrument that measures the fraction of the incident light transmitted through a solution.  In other words, it is used to measure the amount of light that passes through a sample material and, by comparison to the initial intensity of light reaching the sample, they indirectly measure the amount of light absorbed by that sample.

Spectrophotometers are designed to transmit light of narrow wavelength ranges (see Figure 1 the electromagnetic spectrum).  A given compound will not absorb all wavelengths equally-that's why things are different colors (some compounds absorb only wavelengths outside of the visible light spectrum, and that's why there are colorless solutions like water).  Because different compounds absorb light at different wavelengths, a spectrophotometer can be used to distinguish compounds by analyzing the pattern of wavelengths absorbed by a given sample.  Additionally, the amount of light absorbed is directly proportional to the concentration of absorbing compounds in that sample, so a spectrophotometer can also be used to determine concentrations of compounds in solution. Finally, because particles in suspension will scatter light (thus preventing it from reaching the light detector), spectrophotometers may also be used to estimate the number of cells in suspension.

We will be using a spectrophotometer several times this semester to quantify the concentration of chemicals present in a solution.

 

922_Basic principles of spectrophotometry.png

 

Posted Date: 10/15/2012 5:40:15 AM | Location : United States







Related Discussions:- Basic principles of spectrophotometry, Assignment Help, Ask Question on Basic principles of spectrophotometry, Get Answer, Expert's Help, Basic principles of spectrophotometry Discussions

Write discussion on Basic principles of spectrophotometry
Your posts are moderated
Related Questions
A beam of light of wavelength λ = 5000Å falling normally on a plane diffraction grating. The 1 st order spectrum is derived in a direction making an angle θ 1 with the norma

Define Space Station Pressure (MIT)? A space station consists of a huge cylinder of radius Ro filled with air. The  cylinder revolve about its symmetry axis at an angular  spee

A cheetah can reach a top speed of 27.8 m/s in 5.2 s. What is the cheetah's average acceleration?


A proton with a velocity of 3.98 x 10 4 m/s perpendicular to the direction of a magnetic field follows a circular path with a diameter of 4.12 cm. If the mass of a proton is 1.


define pseudo force and mathematical expression and explanation

The radioisotope 222 84 Po undergoes alpha decay to form an isotope of lead (lead has atomic number 82). Verify what the mass number of that isotope must be by writing a nuc

does lights of different wavelengths help us to see different colour

A projectile is launched from zero height with an initial angle, θ, above the horizontal and with an initial velocity, vi. a. Show that the range of the projectile the distance