High performance thin layer chromatography analysis of deltamethrin residue on the impregnated bed nets during a leishmaniasis control program in Iran

The control of leishmaniasis, a tropical neglected disease, has been concern of Iranian health authorities due to the increasing number of cases during the last two decades. The objective of this study was to determine deltamethrine residue on the impregnated bed nets using HPTLC technique in a leishmaniasis control program in Iran. During this experimental study, a total of 130 small pieces of polyester netting were sewn to top, upper, and lower sides of some bed nets and then were impregnated with deltamethrin .The treated bed nets were distributed in Isfahan and Mashhad areas in April 2003. The samples were cut randomly after impregnation intervals. Deltamethrin was extracted using acetone from samples and the extract was applied for spotting onto plates. The plates were developed with n-hexane: ethyl acetate, 90+10[v/v], as a mobile phase in a Camage chamber. The qualifying of residue was observed in UV cabinet with lambda =254 nm wavelength. Data were analyzed using SPSS version 11.5. and Stata Version 8. A three way ANOVA was used to compare the means of deltamethrin residue in each area, group and measuring time. The Kruskal-Wallis test was used to compare the means of residue for each of these factors with the control separately. The retardation factor of deltamethrin was calculated 0.50 +/- 0.02. The residues of deltamethrin persisted well on impregnated nets at least for 15 weeks after impregnation. No significant difference could be detected in the loss of residue of insecticide in comparison to measuring times and positions of sampling pieces on the bed nets in these areas. Based on the results of the present study the use of HPTLC technique is recommended instead of other chromatographic methods for analysis of insecticide residue on the impregnated bed nets

Residual effect of etofenprox [trebon 20 % WP] as a new insecticide on different surfaces in south of Iran

The residual activity and air-borne efficacy of Etofenprox [trebon 20% WP] were studied on different surfaces in hut scale trial, in Kazeroun south of Iran, in 1992. The bio-assay contact mortality tests with trebon against Anopheles stephensi showed similar responses on pluster, cement and mud surfaces [except wooden surfaces], i.e. at 250, 400 and 500 mg/m2, trebon had residual activity for about 75 to 82, 95 and 110 days respectively. On wooden surfaces, trebon showed longer residual activity than the latter surfaces, i.e. at 250, 400 and 500 a.i. mg/m2, trebon had residual activity for 90, 110 and 127 days respectively. Fumigation test with trebon at different rates of application showed no remarkable effect on An.stephensi. Based on the results of this study, trebon at 500, 400 and 250 mg/m2 had a residual activity for about 4, 3 and 2.5 months on different surfaces and hence the recommended dosages for continuation study could be 500 and 250 mg/m2 in a large scale trial in south of Iran

Residual and air-borne effects of pirimiphos-methyl on different surfaces in South of Iran

An investigation was made to study the residual activity and air- borne effect of pirimiphos- methyl, at 2g a.i./m2 in hut scale trials on different surfaces in kazeroun, and Bandar-Abbas, south of Iran. In Kazeroun area, bio-assay contact mortality test with pirimiphos methyl on mud, wood, cement and plaster surfaces, 54 days after hut spraying, decreased from 100% to 46.7%, 61.25%, 36.6% and 40%, respectively. In Baridar-Abbas area, after 72 days of hut spraying, the mortalities on cement and plasters surfaces decreased from 100% to 63.4% and 45.4%, respectively. The fumigation effect of pirirnlphosmcthyl on mud and plaster walls with wooden ceiling were studied in Kazeroun. 'The activity of pirimiphos- methyl on mud and plaster surfaces dropped from 100% to 52% and 46.53% after 54 days of hut spraying respectively. The results suggested that pirimiphos-methyl has effective contact and vapour effect at least for about 50 days on different surfaces in south of Iran