Vol. 8, Issue 12 (2019)

Author(s):
P Janaki, C Chinnusamy and N Sakthivel

Abstract:
Achieving the separation and detection of glufosinate from different matrices by chromatograph below MRL level is a cumbersome and challenging task since it is ionic and highly water soluble. A rapid and sensitive analytical method for glufosinate determination in soil, water and tea was achieved involving Hydrophilic Interaction Liquid Chromatography (HILIC) separation and HPLC-ELSD (Evaporative Light Scattering Detector) detection. The limit of detection of residue by the method was ranged 0.01 mg/kg for tea, soil and water. The method was validated using spiked blank matrix and the mean glufosinate recovery ranged 78.4 to 90.5 percent with replicate standard deviation (RSD) of 1.00 to 2.39%. Developed method was also validated using real samples from tea field experiment conducted with different glufosinate rates. Glufosinate residue was found below MRL (0.01 mg/kg) in tea leaves. Glufosinate dissipation in soil was studied at two rates and found more than 40 percent was dissipated on 30th day. Glufosinate dissipation in soil followed first order reaction kinetics and half-lives were 9.51 and 10.04 days respectively at 0.5 and 1.0 kg/ha application rate. Developed method can be used to evaluate quality of glufosinate formulations and compound safety in food matrices.