The U.S. Environmental Protection Agency (USEPA) recently conducted a validation study of Method 1103.1 (mTEC) for E. coli in wastewater effluent to
characterize method performance across multiple laboratories and disinfected wastewater matrices and to develop
quantitative quality control (QC) acceptance criteria. Ten volunteer participant laboratories, a verification
laboratory, and two research laboratories participated in the study. Each laboratory spiked samples with laboratory-prepared
and BioBall™ E. coli (ATCC 11775) spikes. Method 1103.1 mean laboratory-specific recoveries of E.
coli from disinfected wastewater samples spiked with laboratory-prepared and BioBall™ spikes had an overall
mean recovery of 75.8% and 57.8%, respectively. Laboratory-specific relative standard deviations (RSDs) from
disinfected wastewater samples spiked with laboratory-prepared spikes ranged from 3.7% to 114.6%, with an
overall pooled, within-laboratory RSD of 40.8%. Laboratory-specific relative standard deviations (RSDs) from
disinfected wastewater samples spiked with BioBalls ranged from 0% to 34.6%, with an overall pooled, within-laboratory
RSD of 15.4%. Method 1103.1 laboratory-specific false positive confirmation rates for unspiked
disinfected/secondary results combined, ranged from 0% - 50%. Laboratory-specific false negative confirmation
rates for unspiked disinfected/secondary results combined, ranged from 0% - 66.7%. Results from the
interlaboratory validation studies of Method 1103.1 and Method 1603 were used to compare method performance
based on recovery, precision, false positive and false negative confirmation rates. Method 1103.1 had significantly
higher false positive and negative confirmation rates in comparison to Method 1603.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 150 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 4 |
| Published : | 11/01/2005 |
