Hach BioTector B3500e, User Manual

Page: 64 / 163

Page 64
6.2 Calibration Standards
The following compounds can be used to prepare calibration standard solutions in BioTector.
To prepare a 1000mgC/l Total Organic Carbon (TOC) standard solution, use one of the following:
•
Potassium Hydrogen Phthalate, C
8
H
5
KO
4
, 2.13g (99.9% purity) in one liter of deionized water. Water
solubility: 80 g/L at 20°C.
•
Acetic acid, C
2
H
4
O
2
, 2.51g (99.8% purity) in one liter of deionized water. Water solubility: Miscible in
all proportions.
• Glucose, C
6
H
12
O
6
, 2.53g (99% purity) in one liter of deionized water. Water solubility: 512g/L at 25°C.
To prepare a 1000mgC/l Total Inorganic Carbon (TIC) standard solution, use one of the following:
•
Sodium Carbonate, CNa
2
O
3
, 8.84g (99.9% purity) in one liter of deionized water.
• Sodium Hydrogen Carbonate, CHNaO
3
, 7.04g (99.5% purity) in one liter of deionized water.
•
Potassium Carbonate, CK
2
O
3
, 11.62g (99.0% purity) in one liter of deionized water.
All hygroscopic chemicals in crystal form should be dried in an oven set at 105°C for 3
hours to remove any traces of absorbed water. All prepared solutions must be mixed
thoroughly with a magnetic stirrer or inverted manually at least ten times or until all
crystals are completely dissolved inside the solution.
The quantity of concentrated chemical required to prepare stock calibration solutions
will change with the % purity of the chemical used. If the purity of the chemical is
different than the figures displayed above, the necessary quantity needs to be
recalculated from the purity of the chemical. See example in the following page.
Depending on the system analysis ranges (see System Range Data menu), every
BioTector requires specific calibration standard solutions. The required concentration of
the calibration standard solutions can be identified in Span Calibration menu.
Caution
Caution