Development and validation of a new sensor for methomyl detection

Abstract

Award Number: N00014-14-1-0425 https://www.sfos.uaf.edu LONG-TERM GOALS To promote the use of endocrine techniques to advance our knowledge of the physiology of cetaceans and their responses to change in their environment. OBJECTIVES Two objectives are being nested under the overall goal of developing techniques that can be used for the detection of stress and pregnancy in large whales. 1)The first objective is to develop and conduct analytical and preliminary biological validations of pregnancy and stress hormones for large whales (humpback whales, blue whales, and possibly insular false killer whales). 2) The second objective is to complete the biological validation using archived samples from whales with known life history or behaviors. APPROACH The project has a two year approach in which the first year will serve as the proof of concept and the second year will complete the validation and add in life history and behavior data. Details of each year's activities are separated below. Year 1-Commercially available radioimmunoassays (RIA) previously validated in other marine mammal species will be validated for corticosterone or cortisol and progesterone in humpback whale blubber. The validation will follow two forms, analytical and biological, described below. Analytical Validation: The analytical validation will be conducted using standard methods of parallelism, accuracy and metabolite identification using high-pressure liquid chromatography (HPLC). Briefly, pooled blubber extract from animals of known gender will be serially diluted 1:2 and run as samples, in duplicate, in the assay to determine displacement by the pool. Accuracy of the assay will be determined by spiking the pool at the appropriate dilution with known amounts of hormone then performing the assays. Mass of the pool will be calculated and subtracted from the mass measured

A Review of Nanocomposite-Modified Electrochemical Sensors for Water Quality Monitoring

“…Electrochemistry of pesticides using oxide-based electrodes is also a relatively new approach for pesticide detection. Methomyl detection using copper-oxide modified carbon paste electrode was demonstrated by Abbaci et al [ 78 ] with a LOD of 0.02 μM. At the same time, CuO microspheres were employed for the detection of α-endosulfan using differential pulse voltammetry [ 79 ].…”

Selective Detection of Methomyl Pesticide by a Catalytic Chemosensing Assay

“…National tolerances of the maximum amount of methomyl residue (0.2–6 mg kg −1 ) in fruits and vegetables have been established in several countries [9] . The general approaches for the determination of methomyl are based on GC, HPLC, electrochemistry, and enzyme immunoassay [8b,10] . However, these methods for methomyl have several practical limitations, such as instrumental complexity requiring professional operation, sample manipulation with toxic organic solvents, and long analysis time.…”

Boron-doped diamond as a sensor for the classification of carbamate pesticides using a chemometric approach

“…In contrast, electrochemical methods are easily portable, show high sensitivity and are relatively inexpensive, and hence, such methods are excellent alternatives for in-field analysis and rapid decision-making. 4,6 Many studies reported in the literature have used voltammetric techniques to quantify carbamates with various electrode materials such as mercury, 27 glassy carbon, 3,4,28,29 gold, 30 borondoped diamond (BDD), 31,32 modified electrodes, 6,25,[33][34][35] and biosensors. [36][37][38] It is difficult to directly oxidise carbamates on the surface of conventional electrode materials such as glassy carbon, platinum, and gold because of the large potential required.…”

“…Hence, performing an alkaline hydrolysis process to transform the carbamate groups into hydroxyl groups and thus facilitate their analysis is a common practice. 4,31,33 However, this derivatisation step may be avoided by using BDD materials, which present a large anodic potential range compared with that of conventional materials 39 and thus do not require any sample derivatisation pre-treatment. The use of eco-friendly BDD electrode to detect and quantify pesticides based on their reduction process has been used as an alternative material to replace mercury electrode.…”