Using the AA240
Atomic Absorption Spectroscopy

AAS Spectrometer Setup Instructions
pdf version

Switches | Gases| Worksheet | SamplingMode | Method| Standards | Calibration | Analyze-Setup | Flame-Setup | Sampe Run |

Miramar College, S5-210
Viarian AA240 AAS


 AA240 Spectrophotometer at Miramar College

Features of the Varian AA240 spectrometer


Basic Design of an Atomic Absorption Spectrometer





Preparing Instrument for Operaton

Flip the switch to turn on the fume hood above the spectrometer

Turn on the instrument by pressing the power button on the computer


Gas settings

Turn on the the first stage valve on the oxygen and acetylene gas cylinder

(Note that the acetylene tank should not go below the 400 psi.
If the pressure is less than 400 psi, it is time to replace the cylinder)

Acetylene: Turn the second stage valve to 75 psi

Oxygen: Turn the second stage valve to 40 psi.


Opening Screen for Specta AA

On the opening screen, click on Spectra AA

Click on the Worksheet.


Worksheet Menu.

Click on worksheet (create new worksheet)

Click on New

Type in filename


Worksheet → Filing

The opening menu after the worksheet is create opens under "filing"

Note the menu selection: Filing - Develop - Labels - Analysis


Worksheet → Development → Methods

Click on the Develpment tab and choose add methods

Select Method Type: Flame

Element Selection: Sodium, Copper Calcium

(Choose: Na)


Worksheet → Development → TypeMode→ Manual

Select Sampling mode: Manual


Worksheet → Development → Methods → Measure

Select Measure mode: Integration
Select Calculation mode: Concentration


Worksheet → Development → Methods → Optical

The lamp position is set for the element selected automatically.

The wavelength is set for the linemax of the element source.

Selec the wavelenght that will be used from the lamp.

Worksheet → Development → Methods → Standards

Skp the SIPS tab (The Instrument does not have SIPS accessories)

The menu will show a list of standards.
This list can be use to set up the calibration curve in a Beer-Lambert Analysis.

Concentrations are entered in the "Conc" column.

Enter the appropriate unist under "StdUnits" box.

Worksheet → Development → Methods → Calibration

Choose the Calibration tab

Selecvt the Linear (Beer-Lambert) calibration algorithm.

Worksheet → Development → Methods

Skip the following tabs:
QC Tests
Cookbook tab

Click on "OK" at the bottom

Worksheet → Labels

Select the Labels tab under worksheet.

The screen will show a list of samples to be analyze.
Choose the number of samples to be analyze (note these are not your standards).

Worksheet → Analyze

Select the Analyze tab under worksheet.

Adjust the lamp to maximize the lamp.

Adjust the screws at the base of the lamp to maximize lamp signal.

Worksheet → Analyze
(Turn on instrument Flame Switch)

Worksheet → Analyze

Under the Analysis screen-
Adjust the flame to maximize the signal detected

Click on "OK" at the bottom of the screen.

Worksheet → Analyze

Under the Analyze menu-

Click on select and select the standards and samples to analyze

Click on Analyze.

Worksheet → Analyze

The spectrometer will ask for standards and samples.

These values will be used to do a Beer-Lambert calculation

Upon completion of the experiment, the flame will be extinguished by the instrument

Processing the Data

Print the Results

Allow the instrument to cool down for 15 minutes then turn off the AA spectrometer.

Turn off the computers

Close the primary valve then the secondary valve for the acetylene and oxygen gas,

Turn off the ventilator fan