A Portable e-nose for Monitoring Amitraz Insecticide in Cattle Dip

Abstract

Amitraz is an effective acaricide used in the control of external parasites for livestock. This study investigates the responses of general-purpose metal oxide (MOX) gas sensors to Taktic (a brand name insecticide containing amitraz) in water. An array of MOX sensors is used to design a custom electronic nose (e-nose) device to predict the concentration of Taktic in distilled water. The gases produced by the Taktic show a largely time-dependent response. A neural network is trained on a dataset with 5 concentration levels with time included and excluded as an input variable, and achieves a 100 % training and validation accuracy on different samples from the same sample set. The custom-built device is able to function as an early warning system for when the Taktic concentration falls below the efficacy minimum. The system is used for generalisation analysis of measurements taken from the same sample set at a later time and predicts the concentration correctly for all measured samples. An e-nose can be used for qualitative Taktic detection in water, and is adequately suited to semi-quantitative concentration prediction. Although the system can be further optimised, five levels of Taktic concentration can be discriminated in its current form. The results suggest the need for time-dependent signal conditioning like decay monitoring, as well as individual sensor sensitivity optimisation that include temperature and humidity compensation, to improve the results and practical feasibility of such a system.