Current Projects of the Pesticide Subgroup

by Subgroup Chair, Jon Wong
September 22, 2008

Pesticide Subgroup Members:

   The Pesticide Subgroup met at the 122nd AOAC meeting in Dallas in September.  Julie Kowalski of Restek Corp. was kind enough to summarize the meeting (see attachment).  The subgroup, the largest of the four, has over 350 members representing government agencies, private laboratories, academia, and industry.  The only means of communication between members is through the website:  www.flworkshop.com\community-1st.html.  AOAC needs to support and improve networking among members.  

Dr. Guo-Fang Pang of the Qinhuangdao Entry-Exit Inspection and Quarantine Bureau, People’s Republic of China, has announced that he will initiate a collaborative for a multiresidue procedure to analyze pesticides in teas.  Anyone interested in participating in this collaborative or has any questions can contact Dr. Pang directly: qhdciqgfpang@yahoo.com.cn.  The collaborative is expected to begin next year (2009).  Dr. Pang was the seminal speaker of the Contaminant Community Session and his talk “The Systematic Study on Analytical Techniques of Over 1000 World Commonly-Used Pesticide and Veterinary Drug Residues in Food of Plant and Animal Origin” is attached for your viewing.    

Some issues were brought to the attention of the subgroup members who attended the meeting and brought their input, experience and expertise.  One issue was that AOAC wanted guidelines for single laboratory validation for pesticides, similar to the AOAC guidelines for single laboratory validation for dietary supplements.  There was a general consensus among members that there are already single laboratory validation protocols for pesticides established by other organizations (the European Commission, the U.S.  Environmental Protection Agency, and the Florida Department of Agriculture and Consumer Services) that AOAC can refer to as reliable and well written references.  Any procedure (such as a manuscript) or collaborative ought to be able to refer to these sources and references for validation criteria.

QuEChERS is an official AOAC and European Commission method and its popularity has grown to not only include the analysis of pesticides but also to mycotoxins, antibiotics, and other organic contaminants.  However, the official QuEChERS method is currently being modified by researchers and there is a concern whether these modifications ought to be validated.  Some of these modifications include the use of different salts (NaCl, Na-citrate, Na-acetate, etc.), solvents (i.e., ethyl acetate) and sorbents (C-18, graphitized carbon, anion/cation exchange sorbents). The general feeling from members was that multilaboratory validation of the QuEChERS modifications is not necessary because accredited laboratories are performing single laboratory validation on the modified versions according to ISO guidelines.  There are also so many factors that can be modified that all of these variations cannot all be validated.  QuEChERS is a modular process and its flexibility allows it to be easily modified or adapted to optimize the analysis of the analyte.   

Subgroup members were asked if there was a need for an official AOAC multiresidue method for pesticide analysis.  The reason is that industry may need a validated multiresidue procedure for screening pesticides in food and agricultural products.  Subgroup members felt that this was not necessary since there are many validated procedures available.  Instead, members felt that there ought to be an efficient procedure for the analysis of pesticides in fatty foods or foods containing a high lipid content.   Finally, it was suggested that a study between these multiresidue methods could be compared in a collaborative study.  This type of collaborative could be an effective way to ensure data quality and validity between the various methods. 

That was about all that was presented and discussed.  Please don’t hesitate to communicate your thoughts to the community.

Jon

Contact Sub Group Chair at: Wong, Jon [jon.wong@fda.hhs.gov]

Pesticide SubGroup Members (based on database on 2007-06-26)

SubGroup Report, April 14, 2008

SubGroup Report, February 3, 2008

Minutes of Meeting: September 17, 2007