Processing kodak motion picture films, module 3 analytical procedures

Cerimetric Determination of CD-2 Contamination in Eastman Color Print-2 First Fixer
ECP-2-2020
Process ECN-2 ECP-2D VNF-1/LC RVNP
Formulas — F35B, 35D — —
PRINCIPLE
A sample of fix is made alkaline (over pH 9.0) and the CD-2
is extracted with chloroform. The CD-2 in the chloroform is
then extracted into dilute acid and titrated with sulfato cerate
using ferroin as an indicator.
RELIABILITY
CD-2 additions were made to a sample of seasoned fix. Four
samples were each run by two analysts. Using the
stoichiometric equation:
0.0107 (mL of cerate) – .001 = g/L CD-2
The results were:
CD-2 Added g/L CD-2 Found g/L
0 0.03 , 0.03
0.10 0.12, 0.12
0.20 0.22, 0.22
0.40 0.41, 0.41
REAGENTS
10 N Sodium Hydroxide, NaOH
pH 11.1 Sodium Carbonate Buffer, Na 2CO 3
1.0 N Sulfuric Acid, H 2SO 4
0.0500 N Sulfato Cerate, (NH 4) 2Ce(NO 3) 6
Ferroin Indicator
PROCEDURE
Extraction of CD-2 into Chloroform
1. Add from graduated cylinder 500 mL of sample to a
one-litre separatory funnel.
2. Add 25 mL of 10 N sodium hydroxide from a tip-up
pipet to the funnel.
3. Add 100 mL of pH 11.1 sodium carbonate buffer with
a 50-mL tip-up pipet to the funnel.
4. Add 100 mL of chloroform with a tip-up pipet to the
funnel stopper and shake 30 seconds, venting
occasionally.
Extraction of CD-2
1. Add 50 mL of 1.0 N sulfuric acid to a 250-mL
separatory funnel.
2. Drain the chloroform layer from the one-litre
separatory funnel into the 250-mL funnel. Shake for
30 seconds.
3. Allow the layers to separate and discard the lower
chloroform layer.
4. Drain the acid layer into a 150-mL beaker equipped
with a magnetic stirring bar. Rinse the 250-mL funnel
with distilled water, adding the rinse to the beaker.
5. Ad 4 drops of ferroin indicator to the beaker and titrate
with 0.0500 N sulfato cerate to a green end point.
Calculations
0.0107 (mL cerate) – .001 = CD-2, g/L
Processing KODAK Motion Picture Films, Module 3, Analytical Procedures H24.03 1