Processing kodak motion picture films, module 3 analytical procedures

Potentiometric Determination of Total Alkalinity of EASTMAN Color Films Developer
ECN-0001/1
ECP-0001/1
Process ECN-2 ECP-2D VNF-1/LC RVNP
Formulas SD-49
SD-50
SD-51
TBD TBD
INTRODUCTION
The total alkalinity of a photoprocessing solution is defined
as the millilitres of 0.1000 N sulfuric acid required to adjust
a specified volume of photoprocessing solution to a pH of
4.3. To determine total alkalinity, a pH meter with a pH
indicator electrode and a calomel reference electrode is
calibrated according to the procedure described in Method
ULM-191-2, pH Measurement of Photographic Processing
Solutions, or subsequent pH method. A specified volume of
photoprocessing solution is titrated to a pH of 4.3 with
0.1000 N sulfuric acid. The volume of sample used in the
titration must be reported along with the mL of 0.1000 N
sulfuric acid required for the titration
A pH of 4.3 was chosen for the end point because, when
titrated with acid, most buffering constituents in
photoprocessing solutions show an inflection point near 4.3.
The end point determination will be more precise when the
pH of the solution is changing quickly (near an inflection
point) than when the pH is changing very gradually.
Use of this methods requires handling of potentially
hazardous chemicals. Material Safety Data Sheets should be
consulted for each chemical before use. These can be
obtained from each chemical supplier.
PRECISION AND BIAS
A fresh tank solution was analyzed four times on one day by
both a manual and an automated titration. The manual
titration was performed by an experienced analyst. The
automated titration was supported by a robotic sample
handling system.
A replenisher sample and a seasoned developer tank
sample were obtained from a processor and were analyzed as
received in the same manner as the fresh sample.
Repeatability Standard Deviation, 1s r
All values are expressed in units of mL of 0.1000 N sulfuric
acid, and were determined using a sample size of 5.00 mL.
ECN-2 Developer
Manual Method,
1S r
Automated Method,
1S r
Fresh Tank 0.0 0.06
Seasoned Tank 0.0 0.81
Replenisher 0.082 1.92
ECP-2D
Developer
Manual Method,
1S r
Automated Method,
1S r
Fresh Tank 0.05 0.05
Seasoned Tank 0.08 0.71
0.05 0.05 0.70
95 Percent Confidence Estimate
(not including bias)
The 95 percent confidence estimate (calculated using the
repeatability standard deviation) around a single test result
will include the mean total alkalinity 95 percent of the time.
ECN-2
95 Percent Confidence Estimate
Developer Sample Manual Method Automated Method
Fresh Tank ± 0.0 ± 0.18
Seasoned Tank ± 0.0 ± 2.60
Replenisher ± 0.26 ± 6.12
ECP-2D 95 Percent Confidence Estimate
Developer Sample Manual Method Automated Method
Fresh Tank ± 0.16 ± 0.16
Seasoned Tank ± 0.26 ± 2.25
Replenisher ± 0.16 ± 2.24
Comparison of Precision for Manual and
Automated Procedures
The total alkalinity of forty-one photoprocessing solutions
from fourteen different photoprocesses * were determined
four times each by both the manual and automated
procedures described here. The manual procedure was
performed by an experienced analyst. The standard
deviations resulting from the manual titrations were pooled,
as were the standard deviations of the automated titration
results. The pooled standard deviations (n=41) represent a
good estimate of the variability for each procedure.
Procedure Pooled Standard Deviation
Manual 0.13
Automated 0.41
Note: The precision study for the manual method was
performed by a single, experienced analyst. If a multiple
analyst study were performed, the pooled standard deviation
would likely be greater than the pooled standard deviation of
the automated method.
* PROSTAR, POLYMAX, RP X-OMAT, ULTRTEC, X-OMAT RA/30,
C-41, E-6, ECN-2, ECP-2, EP-2, R-3, RA/RA4, RA 100, RA/RT
Processing KODAK Motion Picture Films, Module 3, Analytical Procedures H24.03 1