1969 EVALUATIONS OF SOME PESTICIDE RESIDUES IN FOOD
Issued jointly by FAO and WHO
The content of this document is the result of the deliberations of the
Joint Meeting of the FAO Working Party of Experts and the WHO Expert
Group on Pesticide Residues, which met in Rome, 8 - 15 December 1969.
FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
WORLD HEALTH ORGANIZATION
This compound was considered at the Joint Meetings in 1965 when a
monograph was issued (FAO/WHO, 1965b), and in 1966 and 1968 when
addenda were issued (FAO/WHO, 1967b and 1969b).* The latter addendum
(page 262) expressed the need for "an analytical method that is
specific for phosphamidon and its N-de-ethyl derivative". Information
received from CIBA Ltd. concerning such a method was drawn to the
attention of the 1969 Joint Meeting which decided to issue this
addendum on the subject.
METHOD OF RESIDUE ANALYSIS
The plant or other material is extracted with acetonitrile or
methylene chloride. After portioning between solvent phases, the
extract in chromatographed on a silica gel column and then on a
thin-layer chromatoplate. The appropriate portions of adsorbent are
removed from the plate and the compounds elated. Quantitative
determinations are then made by gas chromatography using a phosphorus
flame photometric detector.
The procedure will determine both cis-and trans-phosphamidon and also
its N-des-ethyl derivative. Sensitivity is about 0.02 to 0.04 ppm and
the method is considered to be generally satisfactory.
CIBA Ltd. Determination of phosphamidon residues (Unpub, rept.).
* See Appendix II