4.
d.
1.
2.
3.
4.
1.
2.
3.
4.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
a.
i.
ii.
iii.
b.
i.
ii.
c.
i.
ii.
iii.
iv.
d.
i.
16.
repeat the calibration.
Example: Creating a Calibration Curve for Fe (Iron)
by Golda Yelaun
1. Creating a Calibration Curve
Preparing the calibration standards. Calibration standards are prepared from stock solution 1000 PPM Fe (Atomic Absorption standard).
We prepared three calibrations standards: 2ppm, 5ppm, 10ppm.
In the Manual Analysis Control window we have to click Analyze Blank, then Analyze Standard.Since the Method is already stored all
three standards (2,5,10 ppm) will be analyzed.
The instrument will create the plot Absorbance versus Fe-concentration automatically.
The calibration curves have to be linear. If any of the standards appear to be off the calibration curve, we have to check the standards
and repeat the calibration.
2. Analyzing the samples.
Before analyzing prepared samples we have to put QC sample and Blank for checking the instrument.
Analyzing Reagent Blank (absolute value have to be in the Range 0.2 mg/l)
Analyzing QC standard- 5ppm Fe (have to be closed to 5mg/l)
Analyzing prepared samples.(Concentration of the samples have to be in the Linear Dinamic Range – less than 10 ppm Fe)
To the end of the Run (around 10 samples) to check again Reagent Blank and 5ppm Fe.
Tips For Use
Manuals for the AA are either in the cabinet drawers under the instrument or in Golda Yelaun's office.
A good description of using the AA is available in the
, updated and released every year.
General Chemistry Lab Manual
The AA is calibrated every day, since there are different standards for different elements.
Note!: If the AA generates an error message
, check that the gas is not shut off on the wall behind the AA.
"Can't ignite the flame"
Note!: The numerical readings generated by the AA should be close together. If the numbers jump around, that indicates that the AA
should be cleaned. This might be needed after using a sample that hadn't been filtered well.
If the absorbance signal is low, there may be a problem with the lamp.
Note:!: If the AA is generating unexpected readings, check that the trap flask under the machine is not too full. If it is too full, fumes from
the material in the flask can alter the signal. Check the manual for cleaning instructions.
If the AA is still generating unexpected readings, run 1-1.5 liter distilled water through the trap flask tube to clean it out.
Also check the sample tube for blockages.
The compressed air
be dry grade. Humidity in the compressed air will damage the AA.
must
If the pressure level in the compressed air tank is 200 psi or less, change the tank, since it is almost emtpy.
If the pressure level in the acetylene tank is 10 psi or less, change the tank, since it is almost empty.
The AA software on the PC has the recommended conditions for burning. The different burners are in the cabinet drawers under the AA.
Each lamp has a readout showing usage and condition. Check this to insure that the lamp is in good working condition.
Some troubleshooting tips from Perkin Elmer:
If the results are low:
standard solutions may have be improperly made
blank solution maybe contaminated
weak lamp
If the results are “Noisy”:
burner may be contaminated. Clean the burner head and burner chamber.
sample contaminated.
Flame doesn’t ignite :
Check fuel and oxidant is maintained at proper pressure
make sure the drain interlock is connected
the level of liquid in the drain vessel too low: pour 200-300ml of deionized water into the drain hose.
the level of liquid in the drain vessel too high: empty the drain vessel
Lamp problems:
lamp will not light: lamp not plugged in; lamp is not aligned properly; lamp is old or damaged – try another lamp.
Contact Golda Yelaun with any questions.
