Micro December 2018

3M Petrifilm Rapid E. coli /Coliform Count Plate

BAM e Chapter 4

95% CI g

Cont. level a

Matrix

Mean b 0.000 1.210 2.472 4.424

s r

RSD r

Mean 0.000 1.414 2.513 4.514

s r

RSD r

Mean diff. f

LCL h

UCL i

c

d

Un

NA

NA

NA

NA

NA

NA

NA

Low Med High

0.154 0.146 0.093

12.71 5.892 2.094

0.133 0.083 0.059

9.406 3.310 1.295

-0.204 -0.041 -0.091

-0.378 -0.216 -0.202

0.051 0.105 0.021

Sealed concrete

a All matrices are artificially contaminated when an uncontaminated (Un) level is reported. 1 b Mean of five replicate portions, plated in duplicate, after logarithmic transformation: Log 10 [CFU/g + (0.1)f]. 2 c Repeatability standard deviation. 3 d Relative standard deviation for repeatability. Reported as a percentage. 4 e U.S. Food and Drug Administration Bacteriological Analytical Manual , Chapter 4, Enumeration of Escherichia coli and the Coliform Bacteria. 5 f Mean difference between the candidate and reference methods. 6 g Confidence interval based on paired statistical analysis. 7 h 95% Lower confidence limit for difference of means. 8 i 95% Upper confidence limit for difference of means. 9 k Uncontaminated matrix sample.

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