Development of analytical method for simultaneous determination of chlorantraniliprole and fipronil residues in Moringa leaf using LC–MS/MS and decontamination of Moringa leaves using household reagents

Abstract

Moringa (Moringa oleifera, F: Moringaceae), popularly referred to as the ‘drumstick tree’ or ‘horse-radish tree’ and colloquially known as ‘Muringai’ in Tamil, is a highly sought-after crop in the Indian subcontinent for its nutritious leaves. A modified QuEChERS method was developed for accurate and simultaneous detection and quantification the residues of the two insecticides from Moringa leaves using LC–MS/MS. The method offered high degree of linearity (r2 > 0.99), recovery (70–90 %), and precision (<20%) for analysis of both the insecticides. The matrix interferences, which is a prevalent complication in the analysis of leafy and dark-pigmented matrices, was suppressed by the developed method. Three decontaminating reagents of household importance – sodium chloride, acetic acid and sodium bicarbonate – were tested for their efficacy to reduce the insecticide residue on the Moringa leaves by washing. The combination of sodium bicarbonate carbonate and sodium chloride at 5% each, was found to be the more efficacious among the treatments lowering the chlorantraniliprole residues up to 85.71% and 71.79% in case of X and 2X doses of chlorantraniliprole while the same combination lowered the concentration of fipronil to 67.95 % and 61.15 % for the two doses of the insecticide sprayed on the Moringa leaves. Moringa is an underexploited crop which has immense potential for addressing the nutritional security in the country as well as for export owing to the demand. This work attempts to address the unscientific management practices in on the crop as well as to suggest measures for minimizing the current residue loads by taking the first stride towards developing regulatory limits, which could benefit the researchers and policy makers.