ATOMIC ABSORPTION SPECTROSCOPY
Hands-on Laboratory Experiments
A number of experiments or procedures are available that
support training in atomic absorption spectroscopy for chemical laboratory
Methods offered by ASTM,
will test the students ability to follow an industrial standard method.
Suggested standard methods include:
- E1613-94 Standard
Test Method for Analysis of Digested Samples for Lead by Inductively
Coupled Plasma Atomic Emission Spectrometry (ICP-AES), Flame
Atomic Absorption (FAAS), or Graphite Furnace Atomic Absorption
(GFAAS) Techniques. This test method is intended for use
with digested samples that were collected originally during the
abatement of lead hazards from buildings and related structures.
It covers the determination of lead in sample digestates (for
example, digested paint, soil, dust, and airborne particulate)
using inductively coupled plasma atomic emission spectrometry
(ICP-AES), flame atomic absorption spectrometry (FAAS), and graphite
furnace atomic absorption spectrometry (GFAAS) techniques. It
is a good introduction to the use of AA methods without the difficulties
introduced by more complex samples.
- D3237-97 Standard
Test Method for Lead In Gasoline By Atomic Absorption Spectroscopy.
This test method covers the determination of the total lead content
of gasoline within the concentration range of 0.010 to 0.10 g
of lead/U.S. gal (2.5 to 25 mg/L). The method compensates for
variations in gasoline composition and is independent of lead
alkyl type. The method incorporates extensive sample preparation
but the analysis by AA is relatively simple.
- E1770-95 Standard
Practice for Optimization of Electrothermal Atomic Absorption
Spectrometric Equipment and/or E1184-98
Standard Practice for Electrothermal (Graphite Furnace) Atomic
Absorption Analysis. These practices cover a procedure for
the determination of microgram per millilitre (ug/mL) or lower
concentrations of elements in solution using an electrothermal
atomization device attached to an atomic absorption spectrophotometer.
A general description of the equipment is provided. Recommendations
are made for preparing the instrument for measurements, establishing
optimum temperature conditions and other criteria which should
result in determining a useful calibration concentration range,
and measuring and calculating the test solution analyte concentration.
- D3223-95 Standard
Test Method for Total Mercury in Water (Cold-vapor AA). This
test method covers the determination of total mercury in water
in the range from 0.5 to 10.0 ug Hg/L. The test method is applicable
to fresh waters, saline waters, and some industrial and sewage
effluents. The cold vapor atomic absorption measurement portion
of this method is applicable to the analysis of materials other
than water (sediments, biological materials, tissues, etc.) if
an initial procedure for digesting and oxidizing the sample is
carried out, ensuring that the mercury in the sample is converted
to the mercuric ion, and is dissolved in aqueous media. Both
organic and inorganic mercury compounds may be determined by
this procedure if they are first converted to mercuric ions.
Using potassium persulfate and potassium permanganate as oxidants,
and a digestion temperature of 95°C, approximately 100% recovery
of organomercury compounds can be obtained.
Experiments using AA at academic sites
on the WWW include:
Absorption Spectroscopy (PDF) from the California State University
- Northridge. This is a simple experiment involving the determination
of calcium and magnesium in an artifically-prepared aqueous sample.
It provides a good introduction to the operation of the atomic
absorption spectrometer. A local copy of the PDF file is here.
Furnace Atomic Absorption Spectrophotometry (PDF) from the
California State University - Northridge. This experiment involves
both sample preparation and analysis using an electrothermal
atomizer. Wheat flour is digested using sulfuric acid and hydrogen
peroxide and the manganese concentration is then determined using
electrothermal AA. A local copy of the PDF file is here.
- Effect of Instrumental
Variables on Measurement - Atomic Absorption Spectrometry (PDF) from Hood
College, Frederick, MD. This is an advanced experiment intended to illustrate
the influence of wavelength, slit width, flame stoichiometry, and absorption
pathlength (burner geometry) on the sensitivity and noise in an AA measurement
using copper and potassium. A local copy of the PDF file is here.
Return to Skill Development Module L6.12
Atomic Absorption Spectroscopy Introduction