Processing kodak motion picture films, module 3 analytical procedures

95 Percent Confidence Estimate (not including bias)
The 95 percent confidence estimate (calculated using the
customer standard deviation) around a single test result will
include the sodium sulfite level 95 percent of the time.
ECN-2 Sample
Fresh 3 g/L Na2SO3 Seasoned Sample
(mean = 1.66 g/L Na2SO3) ECP-2D Sample
Fresh 3 g/L Na2SO3 Seasoned Sample
(mean = 3.35 g/L Na2SO3 )
95 Percent Confidence
Estimate
± 0.090 g/L
± 0.090 g/L
95 Percent Confidence
Estimate
± 0.098 g/L
± 0.260 g/L
Bias
Bias is a statistically significant deviation of the mean from
the known sodium sulfite 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 cannot be determined independently of
the test method.
A statistically significant bias was found at all levels for
the Process ECN-2 samples. A low bias of 4.1 percent,
2.4 percent, and 2.9 percent was found at the 1 g/L, 3 g/L,
and 5 g/L levels, respectively. These bias were judged not to
be practically significant.
A low bias of 4.9 percent, 2.5 percent, and 3.6 percent was
found at the 1 g/L, 3 g/L, and 5 g/L levels, respectively for
the Process ECP-2D samples. These bias were judged not to
be statistically or practically significant.
Recovery
Recovery is used instead of bias for seasoned samples, since
the component concentration level cannot be determined
independently of the test method. It is defined as the
calculated mean for the seasoned sample with a standard
addition of the component, divided by the calculated mean
for the seasoned sample plus the actual amount of the
standard addition. It is expressed as a percentage.
The recovery of the standard addition was not statistically
different from 100 percent.
Apparatus
All volumetric glassware should meet all “Class A”
specifications, as defined by American Society for Testing
and Materials (ASTM) Standards E 287, E 288, E 969, and
E 1272 and all referenced documents.
10.0-, 15.0-, and 20.0-mL pipets
250-mL beakers
Automatic titrator with stirrer, METROHM
Potentiograph, Model E536 or equivalent
ORION double-junction reference electrode 900200 or
equivalent (10% KNO 3 outer filling solution)
Platinum inlay electrode, BECKMAN #39373 or
equivalent
Reagents
All chemicals are ACS Reagent Grade unless otherwise
stated.
0.1 N Potassium Iodate, KIO 3 (standardized to 4 places)
0.6 M Potassium Iodide, KI
0.1 N Sodium Thiosulfate, Na2S2O3 (standardized to
4 places)
7 N Sulfuric Acid, H2SO4 Water, Type I Reagent – This method was developed, and
the resulting statistical data were obtained using reagent
water equivalent to purer than Type I Grade, as defined in
ASTM Standard D 1193. Other grades of water, e.g.,
reverse osmosis (RO), demineralized, or distilled water,
may give equivalent results, but the effects of water
quality on method performance have not been studied.
2 Processing KODAK Motion Picture Films, Module 3, Analytical Procedures H24.03