Processing kodak motion picture films, module 3 analytical procedures

Salt Formation
1. Add one drop of Foamex to the flask. Reassemble the
apparatus, but do not apply suction.
2. Pipet 50.0 mL of standardized sodium hydroxide into
the beaker. Swirl the beaker to dissolve any citranzinic
acid that may still be in the beaker.
3. Cautiously transfer the sodium hydroxide to the
Millipore holder.
Note: Do not rinse the beaker; the strength of
hydoxide must not be reduced at this time. See Step 6
below.
4. Swirl the Millipore holder for one minute.
Note: The Celite and citrazinic acid material must
become suspended during the swirling action.
5. Apply suction and filter the solution.
6. Rinse the beaker with distilled water, and cautiously
transfer the rinses to the holder. All solid material must
be transferred to the holder.
7. Cautiously rinse the holder and the Celite with at least
two 20 mL portions of distilled water.
8. Disconnect the suction line, and quantitatively transfer
the filtrate to a 400-mL beaker.
Titration
1. Add six drops of meta cresol purple indicator to the
beaker.
2. While stirring on a magnetic stirrer, titrate the solution
with standardized 0.1 N sulfuric acid to the first clear
yellow.
3. Determine the acid-base blank by pipetting 50.0 mL of
standardized 0.1 N sodium hydroxide into a 150-mL
beaker. Proceed by repeating Steps 1 and 2.
Calculations
Subtract the buret reading recorded in Step 2 of the Titration
procedure above from the reading in Step 3 of the Titration
procedure above. Substitute the difference, (∆mL) in the
following equation:
∆mL = mL Acid blk – mL Acid spl
Citrazinic acid, g/L = 0.0831(∆mL) + 0.01
2 Processing KODAK Motion Picture Films, Module 3, Analytical Procedures H24.03