Fate of Pesticides in Surface Waters, Laboraty and Field Experiments
Appendix E. Experiment with glass and plastic pipettesPlastic pipettes were used in the procedure of adding pesticide work solutions to the test glasses. Therefore, the retention of the pesticide, pendimethalin, with plastic pipettes was compared with that of glass pipettes. The results showed (t-test) that for this compound at a 95% confidence level, there was a measurable difference in the retention by glass and plastic pipettes for both a high and a low concentration. The activity of the glass-pipetted solution was about 2-3% higher than that of the plastic-pipetted solution. Therefore, a small systematic error is introduced when using plastic pipettes, which may account for at least 2-3% of the deficit in the mass balance.  Click on the picture to see the html-version of: ‘‘Table E.1‘‘
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