Investigation of the Potential of Near Infrared Spectroscopy for the Detection and Quantification of Pesticides in Aqueous Solution

Abstract

This research investigates the potential of near infrared spectroscopy (NIRS) for the detection and quantification of pesticides in aqueous solution. Standard solutions of Alachlor and Atrazine (ranging in concentration from 1.25 - 100 ppm) were prepared by dilution in a Methanol/water solvent (1:1 methanol/water (v/v)). Near infrared transmission spectra were obtained in the wavelength region 400 - 2500 nm; however, the wavelength regions below 1300 nm and above 1900 nm were omitted in subsequent analysis due to the poor signal repeatability in these regions. Partial least squares analysis was applied for discrimination between pesticide and solvent and for prediction of pesticide concentration. Limits of detection of 12.6 ppm for Alachlor and 46.4 ppm for Atrazine were obtained.