Processing kodak motion picture films, module 3 analytical procedures

Spectrophotometric Determination of Kodak Reversal Agent in Reversal Color Developer
ECR-0001-1
INTRODUCTION
KODAK Reversal Agent, reducing agent Tertiary
Butylamine Borane (RA-1), reduces molybdophosphoric
acid to molybdenum blue. Since the intensity of the
molybdenum blue is affected by KODAK Anti-Calcium
No. 4, several milliliters of the sequestrant are added to the
reaction mixture to saturate the system. The absorbance of
the molybdenum blue formed is measured at 725 nm.
The molybdenum blue color is both temperature and time
dependent, however it was determined that the temperature
effect is not practically significant when reagents are at room
temperature (20°C-25°C). Time dependence effect is
minimized using a specified procedure time of five minutes.
Use of this method requires handling potentially
hazardous chemicals. Material Safety Data Sheets
(MSDS) should be consulted for each chemical before
use. These can be obtained from each chemical supplier.
PRECISION AND BIAS
A. Repeatability Standard Deviation, 1sr and
95 Percent Confidence Estimate (not including
Bias)
Repeatability standard deviation is an estimate of the
variability one trained analyst should be able to obtain under
favorable conditions (analyzing a sample, with one
instrument, within one day).
The 95 percent confidence estimate (calculated using the
repeatability standard deviation) around a single test result
will include the mean value 95 percent of the time.
To obtain the repeatability data, a single skilled analyst
performed five (5) replicates on each of the following
solutions during methods development.
1. A “fresh” Reversal Color Developer tank prepared
with all components at their respective “working tank”
aim concentrations.
2. A “seasoned” Reversal Color Developer tank
analyzed spectrophotometrically as received, at
113.3 mg/L RA-1.
3. The same “seasoned” solution as in number 2, above,
reanalyzed after making an analytically weighed,
standard addition of 33.0 mg/L RA-1.
Sample
“Fresh”
(prepared at
82.2 mg/L)
“Seasoned”
as Received
“Seasoned”
plus Standard
Addition
Bias
Bias is a statistically significant deviation of the mean from
the known mix level at a 95 percent confidence level. It is
determined for fresh samples only. Bias is not determined for
seasoned samples, since the component concentration level
was not determined independent of the test method.
A bias of 0.8 mg/L RA-1 was found not to be statistically
significant at the 95 percent confidence level.
Recovery
Recovery is used for seasoned samples, since the component
concentration level was not determined independently of the
test method. It is defined as the calculated mean for the
seasoned sample with a standard addition of the component
minus the mean for the seasoned sample, divided by the
actual amount of the standard addition. It is expressed as a
percentage.
Statistically, the recovery of 78.79 percent was
significantly different from 100 percent at the 95 percent
confidence level, but was judged not to be practically
significant.
Processing KODAK Motion Picture Films, Module 3, Analytical Procedures H24.03 1
RA-1
Mean
(mg/L RA-1) N
Repeatability
Standard
Deviation, 1s r
(mg/L RA-1)
95 Percent
Confidence
Estimate
(mg/L RA-1)
83.0 5 1.48 ± 4.1
113.3 5 3.25 ± 9.0
139.3 5 0.84 ± 2.3