4,4'-DDT Insecticide Residue On
Mexican Imported Table Grapes



Victor A Cyr
School of Science and Natural Resources, Env. Sci.
Lake Superior State University
Sault Ste. Marie, MI 49783 U.S.A.




Abstract. Agricultural practices in Mexico include tile use of 4,4'-DDT insecticide during the
production of table grapes . Imported Mexican grape samples were analyzed to determine if
4,4'-DDT was present. As a comparison, Californian grapes were also analyzed. High
Performance Liquid Chromatography/Light Absorbance Detector, rather than the gold
standard of Gas Chromatography/Electron Capture Detector instrumentation, was utilized for
the detection of 4,4'-DDT residue. Six samples of Mexican imported grapes, purchased ftom
three local grocery stores, were analyzed. Each of the six grape samples were divided into
two smaller samples, for a total of twelve Mexican samples. The same process was applied to
five samples of Californian Grapes, for a total of twelve Californian samples. The laboratory
extraction technique perfomed was a modified version of the Luke II Pesticide Residue
Analytical Method, used by the Michigan Department of Agriculture. The extraction analyses
results showed many inconsistencies. In particular, the returns for spiked samples revealed
wide variances. The compiled data suggests an inconclusive study, which may be attributed to
the extraction process and/or the utilizahon of the HPLC/Light Absorbance Detector
instrumentation.



Selected References



Luke,	M . A . et al . 1981. Association of Official Analytical Chemists International, 64 1 187-
	1195.


Michigan. Department of Agriculture, Laboratory Division. Report of Analysis Pesticides
	June 1996. 31.