OMB First to Final Action Recommendation Checklist 11-12-18

3/9/2017

 Special study on the effect of tea hydration on the efficiency of the analytical method Correlation comparison of fortified recoveries of 456 pesticides with pesticide logKow values with the three methods of M1, M2 and M3

Spiked level 0.1mg/kg

M2

100.0

M3

80.0

60.0

M1

40.0

20.0

average of REC

0.0

0.3

1.6

2.6

3.5

4.5

5.4

6.0

median of logKow

Conclusion: M3’s pure acetonitirle extraction has achieved relatively good results for pesticides of different polarities, which takes a balanced, stable and similar to straight trend line. While M1’s hydration increases the extraction efficiency of certain polarity water-soluble pesticides; but the adoption of hexane liquid/liquid partitioning further causes certain loss of extracted polarity pesticides, leading to an arc trend line high in the middle and low at both ends; Overall speaking, M3’s extraction efficiency is superior to M1’s. For M2, hydration procedures are likewise adopted, which increases the extraction efficiency of the pesticides of strong polarities and lowers the extraction efficiency of the pesticides of weak polarity. Because of the application of SPE, the line of M2 is similar to downtrend line with the front rise and the back-end fall. The recovery change diagram for 7 polarity sectors by the three methods

 Organization and implementation of AOAC collaborative study

Collaborators for AOAC collaborative study: 30 labs from 11 countries and regions participated in the collaborative study by GC-MS, GC-MS/MS and LC-MS/MS

USA

Canada

Germany

Spain

Italy

Belgium

Japan

Korea

India

China

Taiwan

America ： USA, Canada; Europe: Germany, Spain, Italy, Belgium; Asia: Japan, Korea, India, China and Taiwan

6