GC ANALYSIS OF SOME ORGANOCHLORINE PESTICIDES USING A BROMINATED INTERNAL STANDARD

The brominated compound 1, 1-bis(4-chlorophenyl)2-bromoethane was spec ifically synthesized for use as internal standard (IS) in the GC analy sis of some organochlorine pesticides. The IS was prepared by reacting commercially available 2,2-bis(4-chlorophenyl)ethanol with triphenylp hosphine and tetrabromomethane. Organochlorine pesticides were tested together with this IS for the linearity of the analytical method in th e pg range of injected pesticides (HCB, alpha- and gamma-HCH, heptachl or, aldrin, op'-and pp'-DDT and its metabolites: op'-and pp'-DDE, op'- and pp'-DDD), using MS detection in the negative ion chemical ionizat ion mode (NICI). GC-ECD was also used to test the IS response and line arity of the method for some of the above pesticides in the pg range o f injected analytes. The synthesized IS was added and analyzed in vege table samples (spruce needle and branch) to prove the applicability of this compound in a GC-NICI-MS analytical method for organochlorine pe sticides in such samples.