Chemical Analysis
Chemical Analysis
5940022ChemAnal.fm Page 33
Figure 9 Standard Additions Decision Tree
Branch B Perform multiple standard additions on a sample of deionized water
as follows:
Note: For this example, a 25 mL sample size and a 50 mg/L iron standard is used.
1. Pour 25 mL of deionized water into a 25-mL sample cell.
2. Add 0.1 mL of the appropriate standard solution to a second 25-mL sample of
deionized water.
3. Add 0.2 mL of the same standard to a third 25-mL sample of deionized water.
4. Add 0.3 mL of the same standard solution to a fourth 25-mL sample of
deionized water.
5. Analyze each of the solutions according to the appropriate procedure.
6. Tabulate the data as is shown below:
A
B
D
C
E
H
I
F
G
K
J
Standards Defective
Repeat B with New
Standards
Repair/Replace
Instrument Apparatus
and Repeat B
Is Instrument Apparatus Working Properly?
Repeat B with
New Reagents
Use Correct
Procedure and
Repeat B
Are
Interferences
Present?
Analysis
Is Correct
Analysis
Is Incorrect
Analysis May
be Correct
Do Multiple Standard
Additions On Sample
Give Uniform Increments?
Is the Procedure in
Use Correct?
Are the Reagents Working Properly?
Yes
No
No
No
Yes
No
Yes
Yes
No Yes
Do Multiple
Standard Additions
On DI Water Give
Correct Recovery?
Yes
No
Are
Interferences
Present?
Yes
No
No
Yes
Did a Single Standard Addition Give the Correct Recovery?
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