1. Atomic Emission Spectrometry By: Alexa Kunch
Chapter 10
Atomic Emission Spectrometry
By: Alexa Kunch

2. Plasma Sources Total rate of Argon gas consumption
Plasma: An electrically conducting gaseous mixture
that contains a significant concentration of
cations and electrons
Overall Net charge due to the concentration
of cations and electrons is zero
Plasmas that use Argon ions can sustain
temperatures as high as 10,000K
Total rate of Argon gas consumption
ranges from 5-20 L/min
The sample is first nebulized, then it is
introduced into the plasma

3. ICP Source Schematic of a typical ICP source similar to the one
found on page 255 of the textbook

4. Applications of Plasma Sources
Useful for both qualitative and quantitative elemental
analysis because plasma sources produce spectra that
are rich in characteristic emission lines
High quality results due to:
High stability
Low noise
Low background
Freedom from interferences
Plasma emission spectrometry allows the determination
of all metallic elements

5. Number of Elements Detected at Concentrations of:
Detection Limits
Number of Elements Detected at Concentrations of:
Method
< 1 ppb
1-10 ppb
ppb
ppb
> 500 ppb
ICP Emission 9 32 14 6
Flame Atomic Emission 4 12 19
Flame Atomic Fluorescence 16
Flame Atomic Absorption 1 25 3
Table 10-3 Comparison of Detection Limits for Several Atomic Spectral Methods (page 269)

6. Chapter 13
An Introduction to Ultraviolet-Visible Molecular Absorption Spectrometry
By Tim Cumming and Meg Dailey

7. Beer’s Law and Other Equations
Transmittance: T=P/P0
Absorbance: A=log(P0/P)
Beer’s Law: A=-logT
A=logP0/P
A=εbc

8. Beer’s Law
“Few exceptions are found to the generalization that absorbance is linearly related to path length. On the other hand, deviations from the direct proportionality between the measured absorbance and concentration frequently occur when I> is constant.”

10. Sources of Instrumental Noise
Case 1: Limited readout resolution or dark current and amplifier noise.
Case 2: Photon detector shot noise
Case 3: Cell positioning uncertainties and source flicker

11. Effect of Slit Width on Absorbance Measurements
As the bandwidth increases, fine detail is lost
Less peaks
Peaks are more rounded
As the bandwidth increases, peak height decreases
Higher peaks with smaller bandwidth

13. Instrumentation Sources Wavelength Selectors Sample Containers
Deuterium and Hydrogen lamps, Tungsten filament lamps, light-emitting diodes, and xenon arc lamps
Wavelength Selectors
Types are filters and monochromators
Sample Containers
Radiation Transducers
Types include photon transducers and heat transducers
Signal Processors and Readout Devices

14. Single-Beams vs. Double Beam
Single-beam instrumentation includes of a lamp, a filter or monochromator, cells, a transducer, an amplifier, and a readout device
Double-beam instruments includes a beamsplitter
Double-beam instruments have more advantages
Compensate for wide variations in source intensity with wavelength
Continuous recording of transmittance and absorbance spectra

15. Single-Beam vs. Double-Beam

17. Typical Instruments Photometers Ultraviolet Absorption Photometers
Visible photometers, probe-type photometers, filter selection
Ultraviolet Absorption Photometers
Spectrophotometers
Instruments for the visible region, single-beam instruments for the ultraviolet-visible region, single-beam computerized spectrophotometers, double-beam instruments, double-dispersing instruments, and multichannel instruments