Voltammetric Behavior of the Insecticide Pymetrozine on a Mercury Meniscus Modified Silver Solid Amalgam Electrode

An Analytical Survey of Trace Heavy Elements in Insecticides

There are many types of insecticides traded in the local and international markets, which vary depending on the type of target insect (e.g., whether crawling or flying). This paper aimed to assess the concentration of trace elements present in the various pesticide formulations (solid, liquid, and gaseous). This study was conducted in two groups: the first group was comprised of zinc, copper, iron, chromium, phosphorus, selenium, and cobalt; the second group included four heavy toxic elements (arsenic, thallium, lead, and mercury). These elements were analyzed by inductively coupled plasma/optical emission spectrometry (ICP-OES).

Improved electroanalytical characteristics for flumetralin determination in the presence of surface active compound

ABSTRACT

The use of square wave voltammetry (SWV) and square wave adsorptive stripping voltammetry (SWAdSV) in conjunction with a cyclic renewable silver amalgam film electrode for the determination of flumetralin is presented. Poor separation of two overlapped reduction peaks is significantly improved when hexadecyltrimethylammonium bromide is used as a component of the supporting electrolyte solution (together with BR buffer pH 9.5). The SW technique parameters were investigated and found optimal as follows: frequency 50 Hz, amplitude 40 mV, and step potential 5 mV. Accumulation time and potential were studied to select the optimal conditions in adsorptive voltammetry. The analytical curve was linear for the flumetralin concentration range from 1.0 × 10-6 to 1.0 × 10-5 mol dm-3 and from 5.0 × 10-9 to 1.0 × 10-7 mol dm-3 for SWV and SWAdSV, respectively. Detection limit of 6.5 × 10-10 mol dm-3 was calculated for accumulation time 60 s at -0.2 V. The repeatability of the method was determined at a flumetralin concentration level equal to 5.0 × 10-9 mol dm-3 and expressed as %RSD = 5.0% (n = 6). The proposed method was applied and validated successfully by studying the recovery of herbicide content in spiked environmental samples.

GRAPHICAL ABSTRACT