Abstract:
WHO-approved insecticides were co-intercalated with hexadecyl-trimethylammonium
(HDTMA) chloride in bentonite in an attempt to improve their persistence. XRD and FTIR
confirmed successful co-intercalation of the insecticides. Bioassays revealed that the
activity of co-intercalated insecticides deteriorated after just one week of accelerated
aging at 40◦C and 90% H. However, when the pH of the bentonite slurry used for
intercalation was reduced with acetic acid to pH = 4.5, the persistence life increased to
113 days. The performance rankingwith respect to both knockdown and mortality was as
follows: Co-intercalated α-cypermethrin > co-intercalated propoxur > co-intercalated
DDT > DDT.
