AA Barebones Guide

SAFETY INFORMATION:

• SAFETY GOGGLES SHOULD BE WORN AT ALL TIMES!!
• DO NOT LEAVE FLAMMABLE/COMBUSTIBLE MATERIALS NEAR THE AA!!
• DO NOT LET ACETYLENE TANK LEVEL DROP BELOW 70 PSI!!
• DO NOT STARE INTO THE LAMP!!

 

Installing and Aligning a Hollow Cathode Lamp

• Choose a lamp of your interest and carefully insert it all the way into the lamp compartment, then pull it back about 2-5mm.
• Connect the lamp plug to the appropriate socket.
• Set the wavelength and the slit width (refer to the AA cookbook).
• Turn on the instrument (switch on the bottom of right side). Wait a few seconds until the screen shows “PERKIN-ELMER MODEL 3100”.
• Press [Param Entry]. Enter the operating lamp current (found on box or lamp). Press [Enter].  (AUTOMATIC GAIN APPLIED flashes).
• Enter the integration time.  This is how long the instrument waits before taking an absorbance reading.  Typical times are .1-.5 seconds.  Press [Enter].
• Press [Energy].  A horizontal bar will show on the screen, press [Gain] to bring the bar on scale if necessary.
• Rotate the Wavelength Control Dial back or forth until you obtain maximum energy as shown by the bar and the number of counts (CTS).
• Adjust the knobs on top of the lamp housing until you get maximum energy.
• Wait at least 10-15 min. before taking data so the lamp can warm up.

 

Igniting and Optimizing the Flame (Air/Acetylene operation)

• Adjust the burner height by turning the horizontal adjustment knob until the light beam (which can be seen by placing a piece of white paper perpendicular to the burner head) is centered over the burner slot.
• Adjust the vertical positioning of the burner head by rotating the knob until the light is near but not hitting the top of the burner head.
• Open the acetylene tank and check the flow to be from 85-100 kPa.
• Open the air valve (on the wall) and check the flow to be from 50-65 psi.
• Turn on the oxidant switch to Air.
• Press the Ignite button.
• Aspirate the blank (water) for 60-90 seconds. Press [A/Z].
• Aspirate a mid-concentration standard. Rotate the horizontal and vertical adjusts to obtain maximum absorbance.
• Aspirate a blank.  Leave the aspiration hose in the water or blank unless you are running samples.

 

Measurement of Atomic Absorption

• Aspirate a blank, press [Cont], [A/Z].
• Aspirate the standards and record the absorbance for each one.
• Aspirate the samples and record the absorbance for each one.

 

Shut Down Procedure

• Aspirate water for a few minutes to clean the burner head.
• Turn the gas control switch on the Pneumatics Control Panel to Off.
• Close all gas source valves.
• Turn the gas control switch to Air to allow the gasses to bleed. Then turn the gas control switch to Off.
• Turn the instrument off.

 

**Note: If you wish, Atomic Emission (AE) can be set up. Please contact Sara or the UIC TA for assistance.