Research article

Chemistry Central Journal

, 6:93

Open Access This content is freely available online to anyone, anywhere at any time.

Validated TLC-densitometry method for the simultaneous analysis of pyrethroid insecticides in agricultural and domestic products

  • Syed Ghulam MusharrafAffiliated withH.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi Email author 
  • , Muhammad ShoaibAffiliated withDivision of Analytical Chemistry, Institute of Chemical Sciences, Bahauddin Zakariya University (B.Z.U.)
  • , Dileep KumarAffiliated withH.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi
  • , Muhammad Najam-ul-HaqAffiliated withDivision of Analytical Chemistry, Institute of Chemical Sciences, Bahauddin Zakariya University (B.Z.U.)

Abstract

Background

Pyrethroids are widely used for the control of pests and insects, as pyrethroids are believed to pose little risk to human health and environment. However, exposure to the pyrethroids exceeding the label directions might adversely affect human health and environment. Hence a careful selection of environment friendly household product is required that must contain exactly the label claimed pyrethroids amount.

Results

A sensitive and robust TLC-densitometric method for simultaneous quantification of commonly used synthetic pyrethroids including esbiothrin, alpha-cypermethrin and cis/trans permethrin in agricultural and domestic products has been developed and validated. TLC aluminum sheets, precoated with 0.2 mm thick layer of silica gel 60 F-254, were used for chromatographic process. Densitometric analysis of chromatoplates was carried out in absorbance mode at corresponding λmax of each pyrethroid. Equally valid common mobile phase for all pyrethroids consisted of hexane-dichloromethane-ethylacetate-formic acid (8:1.5:0.4:0.1 v/v/v/v) which provided sharp and symmetrical peaks of esbiothrin, alpha-cypermethrin, trans-permethrin and cis-permethrin, at R f 0.31, 0.53, 0.6 and 0.65, respectively. Linear regression data for respective calibration curves showed a good linearity for all pyrethroids with r = 0.991-0.996. Limits of detection (LOD) and limits of quantification (LOQ) for all pyrethroids were found in the range of 1.6-2.8 and 4.9-8.5 ng/spot, respectively.

Conclusions

The developed method is applicable for separating the mixture of pyrethroids and at the same time, it is also valid for separating their isomers. The method is reproducible, precise and accurate for the quantitative determination of pyrethroids in agricultural and domestic products.

Keywords

Pyrethroid insecticides Agricultural and domestic products TLC-densitometry