Dr. Guo-Fang Pang to Collaborate method for pesticides in tea

Dr. Guo-fang Pang is beginning a collaborative study for the multiresidue pesticide analysis in teas.  He is seeking qualified laboratories to participate in the collaborative and has provided a presentation of the research, scope and goals of the study.  If your laboratory is interested in participating, please feel free to contact Dr. Pang via email.   However, there will be some changes that differ from his presentation.  We suggest that the number of analytes be reduced to 20-30 compounds, two fortification levels, and the collaborative will also contain analysis of incurred tea samples.  Other edits will be presented later and Dr. Pang will be able to address all questions before August 15, 2010.   A study protocol will be submitted approximately about the time of the AOAC meeting in Orlando, Florida in which Dr. Pang plans to attend and present at the Pesticide subcommittee meeting.  Interested participants will have the opportunity to talk to Dr. Pang personally. 

About the Chemical Contaminants in Food Community - Pesticides Subgroup!

Current Projects of the Pesticide Subgroup

CALL FOR PARTICIPATION

Subgroup Chair, Jon Wong

Dear Pesticide Subgroup Members:

Two topics are on this update:
I) Important meeting dates (pertaining to pesticides) and -
II)  Pesticide Methods Needs.

I.  IMPORTANT DATES

        Some important dates of meetings with an emphasis on pesticides:

1.  June 1-5, 2008:  European Pesticide Residue Workshop, Berlin, Germany.  http://www.bfr.bund.de/cd/9683

2.  June 1-5, 2008:  4th Pan Pacific Conference on Pesticide Science, Honolulu, Hawaii USA.  http://acswebcontent.acs.org/meetings/panpacific2008/index.html

3.  July 20-23, 2008  Florida Pesticide Residue Wokshop, St. Pete Beach, FL USA.   http://www.flworkshop.com/

4.  September 21-25, 2008.  122nd AOAC Annual Meeting & Exposition, Dallas, TX USA  http://www.aoac.org/meetings1/main.htm

5.  Also, AOAC Section Meetings are listed on the website: http://www.aoac.org/SECTIONS/calendarsec.html  Most of the section meetings are held in April.

If I have omitted or left out any other pesticide related meetings, please bring this to my attention.

II.  PESTICIDE METHODS NEEDS

        In the last update (Feb 3), I listed  method needs that various subgroup members requested.  Two on the method needs list were for a multiresidue method and a strategy for these methods to be more efficient and adaptive (Method Needs 1 and 2 of the last email).  So far, there has been little response for participation and interest.  I think part of the reason is that there are many laboratories that have their own multiresidue method and will be difficult to abandon the method and the work that went into developing the methods for another procedure.   Finally, there are stakeholders who are not sure if a multiresidue method is equivalent to other methods because there is a lack of comparison. 

        I pose the following questions to all Subgroup members to initiate and stimulate some discussion and action:

1.  Do we really need another multiresidue method for fresh products of vegetal origin? 
2.  Should there be a study (or studies) that compares an established multiresidue method with other procedures in order to declare these methods as comparable?

3.  Should we take an official AOAC method and somehow modify it (i.e., QuEChERS) to meet the subgroup and stakeholders' needs?

        Regarding 1), personally I don't think another method is necessary because there are plenty of established multiresidue methods already.  Most multiresidue methods are similar involving an extraction step with an organic solvent (acetonitrile, acetone, ethyl acetate, etc.), clean-up steps (SPE, SP dispersion, etc.), and analysis by GC, LC, GC-MS and/or LC-MS.  I think developing another procedure from scratch may not be necessary.

         Regarding 2), this might be a good idea but in order to get this off, I think several things must be in play; 1) participating laboratories need to contribute their present and updated validation data, 2) a statistician will be needed to evaluate all of this complex data, 3) other studies may need to be conducted if methods change or evolve in cases where new pesticides are added to the screening list, and 4) detection limit data are needed to see if some detector or method procedures detect much lower than others.  This harmonization of methods seems feasible, but there are a lot of big "ifs" involved and it will require a statistician to process a huge amount of data.

        Regarding 3), QuEChERS has recently been added as an official AOAC method but there are modifications to the procedure, some modifications even developed by the originators themselves (see http://www.quechers.com/).  I know there are many who are interested in some of these modifications for GC, GC-MS and LC-MS analysis.  Could this be the way for a unified multiresidue procedure?  Or could QuEChERS be the focal point to which all procedures can be compared to as explained in 2)? 

        So, subgroup members, what are your thoughts?  I know all of you are busy but I do value your input and it will add to the discussion.

Thank you for your time,

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, February 3, 2008

Minutes of Meeting: September 17, 2007