Implementing the contamination prevention programs in the pesticide industry by infrared spectroscopy

An infrared spectroscopy based methodology has been successfully developed to implement contamination prevention programs in the pesticide industry. Sensitivity of the IR procedure, traditionally considered the Achilles Hell of the technique, has been improved by using a transmission cell with an open upper side, an internal volume of 35 µL and an optical pathlength of 0.5 mm, providing detection limits of 32 mg L−1 for folpet and 48 mg L−1 for cymoxanil. The manufacturing of folpet and cymoxanil was employed as an example and the IR methodology was validated for the implementation of contamination prevention programs in the pesticide industry. The swab test and rinsate method were employed as sampling methods and results obtained by both were compared and correlated. Samples were analyzed from a qualitative and quantitative point of view. Qualitative information can be obtained by comparing the sample spectra with those of a new IR spectral library with approximately 50 entries of pesticide standards. Positive identification of folpet in all the analyzed samples was obtained. Other pesticides present in swab and rinsate samples positively identified by IR and confirmed by gas chromatography–mass spectrometry (GC–MS), were metalaxyl and chlorpyrifos methyl used in the manufacture of previous formulations. The amount of folpet in the swab and rinsate samples obtained by the developed IR method was compared with those of a reference procedure, being statistically comparable.