Atomic absorption spectroscopy aas i
This presentation is the property of its rightful owner.
Sponsored Links
1 / 14

Atomic Absorption Spectroscopy (AAS)I PowerPoint PPT Presentation


  • 109 Views
  • Uploaded on
  • Presentation posted in: General

Atomic Absorption Spectroscopy (AAS)I. Mentor : Prof. Kuniyuki KITAGAWA Assistant: Dr. Eng.Nelfa Desmira. Visible and Ultraviolet Light. Uv -Vis Spectrometer Double Beam. Light Source UV (Deuterium/D2). Diffraction Grating. 1a. 2. Mirror 1. Slit 1. 1b.

Download Presentation

Atomic Absorption Spectroscopy (AAS)I

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Atomic absorption spectroscopy aas i

Atomic Absorption Spectroscopy (AAS)I

Mentor :

Prof. Kuniyuki KITAGAWA

Assistant:

Dr. Eng.NelfaDesmira


Visible and ultraviolet light

Visible and Ultraviolet Light


Uv vis spectrometer double beam

Uv-Vis Spectrometer Double Beam

Light Source UV (Deuterium/D2)

Diffraction Grating

1a

2

Mirror 1

Slit 1

1b

Light Source Vis (Tungsten)

Slit 2

3

Detector-2

Filter

I0

Reference

Cuvette

Mirror 4

7a

Reference Beam

6a

Lens 1

Half Mirror

5

4

Detector-1

Mirror 2

Sample

Cuvette

6b

7b

Sample Beam

I

Mirror 3

Lens 2


Uv vis spectrometer double beam1

Uv-Vis Spectrometer Double Beam

  • No 1a and 1 b

    • The UV-Visible spectrophotometer uses two light sources, a deuterium (D2) lamp for ultraviolet light and a tungsten (W) lamp for visible light. Two light sources hit Mirror 1 one pass through slit 1 go to diffraction grating (no.2)

  • No 2

    • The grating is able to rotated so a specific wavelength is selectable. From diffraction grating goes to slit 2 and filter (No. 3)

  • No 3

    • A filter is used to remove unwanted higher orders of diffraction.

  • No 4

    • The light beam hits a second mirror

  • No 5

    • splited by a half mirror to 6a and 6b

  • No 6a and 6b

    • Half of the light is reflected (6a), the other half passes through (6b)

  • No 7a

    • One of the beams is allowed to pass through a reference cuvette.

  • No 7b

    • the other passes through the sample cuvette. The intensities of the light beams are then measured at the end


Beer lambert law

Beer-Lambert Law

  • The Beer-Lambert law is the linear relationship between absorbance and concentration of an absorbing species.

  • Experimental measurements are usually made in terms of transmittance (T), which is defined as:T = I / Iowhere I is the light intensity after it passes through the sample and Io is the initial light intensity.

  • The relation between A and T is:A = -log T = - log (I / Io)

    where A is the measured absorbance


Transmittance

Transmittance

The relationship between absorbance and transmittance is illustrated in the following diagram:


Assignment

Assignment

  • Calculate the transmission for absorbance A 0.6 and 0.06

  • How to make correction for background absorption caused by sample matrices   using a one-beam spectrophotometer?

  • Explain the system of single beam Uv-Vis Spectrometer


Atomic absorption spectroscopy aas ii

Atomic Absorption Spectroscopy(AAS) II

Mentor :

Prof. Kuniyuki Kitagawa

Assistant :

Dr. Eng. NelfaDesmira


Atomic spectroscopy

Atomic Spectroscopy

  • A method to analyze the elemental composition using atomic absorption or emission

  • Energy transition electrons of atoms

Absorption

Emission

E1

E1

1

2

3

1

v1

Excited State

Excited State

E2

E2

v2

2

E3

E3

3

v3

E0

Ej

Ground State

Ground State

h = Ei– E0

i = 1.2 and 3

h = Ej – Ei

i = 1.2 and 3


Atomic absorption spectroscopy

Atomic Absorption Spectroscopy

Ej

Beer Lambert Law :

I

I0

E0

Where :

A = absorbance/Emission

T = Transmitance

Atomic Absorption Spectroscopy :

The term used when the radiation absorbed by atoms is measured

E0 and Ej : energy levels where Ej higher than E0.

Arrow line: Absorption


Atomic absorption spectrometry

Atomic Absorption Spectrometry

Atomized Sample

(Flame)

Lens

Radiation Source

Lens

Monochromator

Detector

Flame Atomic Absorption Spectrometry

AAS consist of two type: Flame AAS and Graphite-furnace AAS.

Please open this link : http://www.cee.vt.edu/ewr/environmental/teach/smprimer/aa/aadiag.gif

Output


Atomic absorption spectrometry1

Atomic Absorption Spectrometry

  • Radiation Source

    • Hollow-Cathode Lamp

  • AtomizationSample

    • AAS analyzes atoms in gas phase so atoms in a sample must heated/vaporized in a high-temperature source such as a flame or graphite furnace. Flame AA is suitable to analyze solutions, while graphite furnace AA is able to analyze solutions, slurries, or solid samples.


Atomic absorption spectrometry2

Atomic Absorption Spectrometry

  • Monochromator and Detector

    • AA spectrometers use monochromators and detectors for UV and visible light.

    • Monochromator is used to isolate the absorption line from background light due to interferences.


Atomic absorption spectroscopy aas i

Assignment

  • Explain the detail of flame atomization absorption spectrometry (FAAS)

  • Explain the detail of graphite furnace atomization absorption spectrometry (GAAS)

  • Compare the detection limits of FAAS and GAAS and mention their applications respectively


  • Login