Ionics Instruments 2004 Page E - 5 DLM 30007-08 Rev. A
mL volumetric flask with low TOC, DI water. Calculate and record the
concentration of stock TC standard using the formula:
Concentration
=
Weight of KHC
8
H
4
O
4
in grams * 8 mol C*12.01 g C/mol * 1000
of stock TC (0.1 L) * (204.23 g/mol)
standard (ppm C)
Conc. of stock TC standard (ppm C) ____________________________
Part 3 – Prepare a Dilute TC Standard
Use a volumetric pipette to transfer 25 mL of the stock TC standard to a 1 liter
volumetric flask and dilute with low-TOC deionized water. Calculate and record
the concentration of the dilute standard (~25 ppm C) using the formula:
TC
ADJ.,TC
= (TC
STC
) + (TC of DI Water)
(adjusted TC value) (TC value of standard- calculated in step 2 (TC value of water used to prepare standard in step 1
or TOC value copied from the vial) or TC value measured from the Reagent Water vial)
Conc. of dilute TC standard (ppm C) ____________________________
Use the dilute TC standard immediately. The stock TC standard may be stored
in a sealed dark bottle under refrigeration for 1 week.
Preparation of the IC Calibration Standard
Part 1 – Prepare a Stock IC Standard:
Place a small quantity (1-2 grams) of anhydrous Na
2
CO
3
in a beaker and dry
in an oven at 110° C (230°F) for 2-3 hours. Transfer the beaker to a desiccator
and allow the sample to cool. If the bottle of anhydrous Na
2
CO
3
is always
stored in a desiccator, the drying may be omitted.
Weigh out 0.441 grams of anhydrous Na
2
CO
3
(dried to a constant weight).
Record the weight. Dissolve the Na
2
CO
3
in a 100 mL volumetric flask with low
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