Automated Fourier transform near infrared determination of buprofezin in pesticide formulations

An automated procedure has been developed for Fourier transform near infrared (FT-NIR) determination of buprofezin in pesticide formulations. This methodology is based on on-line pesticide extraction with acetonitrile from solid samples and its determination by using peak area absorbance measurements between 2147 and 2132nm, corrected with a horizontal baseline established at 2091 nm. The repeatability, as a relative standard deviation of five independent analyses of 18.9 mg g(-1) of buprofezin, was 0.06% and the limit of detection 5 mg L-1. The reagent consumption was clearly reduced compared with a chromatographic reference procedure from 40.4 mL acetonitrile per sample, required by high performance liquid chromatography (HPLC), to 2 mL acetonitrile consumed for FT-NIR. The sample measurement throughput obtained by the FT-NIR methodology was 30 h(-1), five times higher than that obtained by HPLC (6 h(-1)). It can be concluded that the proposed vibrational spectroscopic method is appropriate for the quality control of commercial pesticide formulations. The on-line sample treatment avoids contact by the operator with toxic products and this method is an environmentally friendly alternative to the measurement in the mid infrared which requires the use of CHCl3.