Recovery

Recovery is used instead of bias 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. The table below shows whether or not a recovery is statistically or practically different from 100 percent.

POTENTIOMETRIC RECOVERY, Process ECN-2

Analyte

Recovery Value

Statistically Significant

Practically Significant

 

 

 

 

Hypo Index (1 mL)

76%

Yes

No

 

 

 

 

Thiosulfate (S2O3=)

74%

Yes

No

 

 

 

 

Sodium Sulfite (Na2SO3)

80.4%

No

No

 

 

 

 

Reliability

Customer Standard Deviation, 1sc & 95 Percent

Confidence Estimate (not including bias)

The customer standard deviation is an estimate of the variability a customer could expect when submitting a sample to any Photoprocessing Quality Services laboratory, where any trained analyst could test the sample using any instrument on any day.

The 95 percent confidence estimate (calculated using the customer standard deviation) around a single test result will include the mean value 95 percent of the time.

HYPO INDEX

Samples (Process

Mean Level

 

Reproducibility

95 Percent

(N)

Standard Deviation, 1Sc

Confidence Estimate

ECN-2 Fixer)

(mL 0.1 N I2)

 

(mL 0.1 N I2)

(mL 0.1 N I2)

 

 

 

“Fresh” at “Aim”

12.88

16

0.25

±

0.54

 

 

 

 

 

 

“Seasoned”, As

12.73

16

0.13

±

0.27

Received

 

 

 

 

 

 

 

 

 

 

 

“Seasoned” with

15.83

16

0.16

±

0.33

Standard Addition

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

THIOSULFATE

 

 

 

 

 

 

 

Samples (Process

Mean Level

 

Reproducibility

95 Percent

(N)

Standard Deviation, 1Sc

Confidence Estimate

ECN-2 Fixer)

=

(g/L S2O3 )

 

=

 

=

 

 

 

(g/L S2O3 )

(g/L S2O3 )

“Fresh” at “Aim”

108.14

16

0.94

±

2.00

 

 

 

 

 

 

“Seasoned”, As

114.86

16

0.73

±

1.56

Received

 

 

 

 

 

 

 

 

 

 

 

“Seasoned” with

142.23

16

0.78

±

1.67

Standard Addition

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SULFITE (Na2SO3)

 

 

Samples (Process

Mean Level

 

Reproducibility

95 Percent

(N)

Standard Deviation, 1Sc

Confidence Estimate

ECN-2 Fixer)

(g/L Na2SO3)

 

(g/L Na2SO3)

(g/L Na2SO3)

 

 

 

“Fresh” at “Aim”

20.79

15

0.59

±

1.26

 

 

 

 

 

 

“Seasoned”, As

15.70

16

0.68

±

1.45

Received

 

 

 

 

 

 

 

 

 

 

 

“Seasoned” with

19.85

16

0.76

±

1.63

Standard Addition

 

 

 

 

 

 

 

 

 

 

 

Processing KODAK Motion Picture Films, Module 3, Analytical Procedures

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Kodak ECN-0002/1 manual Recovery, Hypo Index