A simple method for the separation and detection of trace levels of buprofezin, flubendiamide and imidacloprid by NP-HPTLC and RP-HPTLC

Abstract

A study was undertaken to evaluate the retention (RF and RM) and separation (?RF, R F ?, ? and RS) of buprofezin (B), flubendiamide (F) and imidacloprid (I) using n-hexane-acetone (6.5: 3.5 v/v) in the case of NPHPTLC and methanol-water (8: 2 v/v) for RP-HPTLC as mobile phase. The study revealed that increasing the acetone content in NP-HPTLC and decreasing the water content in RP-HPTLC resulted in high resolution with increase in RF values for B, F and I. ?RF > 0.04 and RS > 1.5 were achieved for all pairs of compounds (?RF(B-F) = 0.35, ?RF(F-I) = 0.19, ?RF(B-I) = 0.54, RS(B-F) = 4.12, RS(F-I) = 7.34, RS(B-I) = 2.02 using NP-HPTLC; ?RF(F-B) = 0.23, ?RF(I-F) = 0.26, ?RF(I-B) = 0.49, RS(F-B) = 2.63, RS(I-F) = 2.97, RS(I-B) = 5.92 using RP-HPTLC). Imidacloprid was adsorbed strongly on NP-HPTLC layer and buprofezin on RP-HPTLC layer, as indicated by their high RM values. The maximum absorption of UV for B, F and I was found to be 252, 242 and 276 nm respectively. Stability analysis indicated that these compounds were stable up to 6 h in methanol and on the plates (NP-HPTLC and RPHPTLC layers). This protocol is useful for toxicologists to detect a mixture of these insecticides in forensic as well as environmental samples. © 2018 Current Science Association, Bengaluru.