Processing kodak motion picture films, module 3 analytical procedures

Titrimetric Determination of Citrazinic Acid in Reversal Color Developers
ECR-1612
Process ECN-2 ECP-2D VNF-1/LC RVNP
Formulas — — DR-150/151 DR-150
PRINCIPLE
The citrazinic acid is removed from solution by precipitation
with acid. Celite is added to aid the precipitation by acting as
a collecting agent. A known excess of sodium hydroxide is
added, and a portion of it reacts with an equivalent amount
of the precipitate. The excess hydroxide is then titrated with
sulfuric acid.
This method requires handling potentially hazardous
chemicals. Consult the Material Safety Data Sheet for each
chemical before use. MSDS's are available from your
chemical supplier.
RELIABILITY
The calibration equations were calculated by the method of
least squares from the data obtained by three analysts who
analyzed four laboratory standard mixes of each developer.
The range of calibration for developers is from 1.00 to
2.00 g/L citrazinic acid. Based on 12 analyses, the
95 percent confidence limits for an individual determination
are ± 0.07 g/L citrazinic acid in the developers.
SPECIAL APPARATUS
Millipore filter holder, Pyrex, Catalog No. XX 1004700,
Millipore Corp., Bedford, Mass. 01730
984H Ultra filter, glass paper 4.25 cm, H. Reeve Angel &
Co., Inc., 9 Bridewell Place, Clifton, N. J.
Note: Use pipets and volumetric glassware meeting the
“Class A” definition by the National Institute of Standards
and Technology (NIST).
REAGENTS
Use ACS Reagent Grade reagents unless specified
otherwise.
Celite filter-aid
7.0 N Sulfuric Acid, H 2 SO 4
Foamex
0.10 N Sodium Hydroxide, NaOH
(standardized to 4 decimal places)
Meta Cresol Purple indicator
0.10 N Sulfuric Acid, H 2 SO 4
(standardized to 4 decimal places)
PROCEDURE
Precipitation
1. Add 3 to 4 g of Celite to a 400-mL beaker.
2. Pipet 100.0 mL of sample into the beaker.
3. Add 10 mL of 7.0 N sulfuric acid from a tip-up pipet.
4. Stir on a magnetic stirrer for 15 minutes.
Filtration
1. Prepare a filtration setup using a Millipore filter holder
and a 500-mL filtering flask. Place the glass-fiber filter
paper in the filter holder.
2. After 15 minutes have elapsed, apply full suction.
Transfer the mixture onto the filter paper using a glass
rod; filter the solution. (The precipitate will be easier
to wash if it does not collect on the holder.) Retain the
stirring bar in the beaker by placing a second bar on the
outside of the beaker.
3. Rinse the beaker, stirring bar, and glass rod with two
10 mL portions of distilled water. Transfer each rinse
to the Millipore holder.
4. Disconnect the aspirator filter assembly and discard
the filtrate. Rinse the flask and the tip of the Millipore
holder three times with distilled water. Discard the
rinses.
Processing KODAK Motion Picture Films, Module 3, Analytical Procedures H24.03 1