High Performance Thin Layer Chromatography Analysis of Deltamethrin Residue on the Impregnated Bed Nets during a Leishmaniasis Control Program in Iran

BACKGROUND 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. METHODS 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 λ=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. RESULTS 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. CONCLUSION 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.