Análise de contaminação cruzada em herbicida a base de atrazina por cromatografia gasosa

Abstract

Cross-contamination is a recent topic in the agrochemical sector, especially when compared to the food and pharmaceutical sector whose theme is treated with a greater knowledge of the cause. With the search to demonstrate through the high resolution gas chromatography with flame ionization detector the possibility of commercial products with formulation based on atrazine are contaminated with actives that are not part of its formulation, characterizing the cross contamination. For this, it was developed and validated an analytical methodology capable of qualifying and quantifying possible ametrine, metribuzin and tebuthiuron contaminants in atrazine formulated products during the 2016, 2017 and February 2018 campaigns. The technique showed good results and satisfactory analytical responses. The validation of the method presented a LOQ and LOD of 0.040mgmL-1 and 0.012mgmL-1, respectively, for the three assets in question. The linearity was 0.999 and the recovery ranged from 80.20% to 119.23% among the assets of interest being in accordance with the acceptance criteria of ABNT NBR 14029:2016. As concordance for successive measurements, the method showed good repeatability, ranging from 97.0457% to 99.2988% for ametrine, from 97.8322% to 100.8780% for metribuzin and 97.11652% to 100.6556% for tebuthiuron. After the validation screening, it is safe to quantify the active ametrina, metribuzin and tebuthiuron not belonging to the atrazine-base formulation, the results obtained was that for the active ametrine all the analysed batches are contaminated, however with values below 0,125mgmL-1 established as the maximum value accepted, for the active metribuzin lot 011/18 is contaminated with the value of 0.165mgmL-1, being this value above the maximum accepted, and for the active tebuthiuron no result was found above of the LOD method for this asset.