Dissertação
Determinação multirresíduo de agrotóxicos em casca, polpa e tubérculo de batata empregando método QuEChERS e UHPLC-MS/MS
Fecha
2023-02-16Autor
Amaral, Leonardo Rabello
Institución
Resumen
Pesticides have been intensively used to control pests, weeds and diseases
associated with various crops. Although these compounds protect crops, when the
recommended doses for application are not respected, they can cause damage to
health and the environment. Thus, this study aimed to develop and validate an
analytical method for the multi-residue determination of pesticides in potatoes, as well
as to evaluate the concentrations in the skin and pulp of the tuber using the original
QuEChERS method and ultra-high performance liquid chromatography coupled to
tandem mass spectrometry (UHPLC-MS/MS). To clean the extracts, the dispersive
solid phase extraction technique (d-SPE) was used using C18 as a sorbent. The
method was validated for 82 compounds and the results showed that the method has
a linear response in the range of 0.5 to 20 µg kg-1
. Accuracy and precision were
evaluated at fortification levels 10, 25 and 50 µg kg-1
(n= 7), in repeatability and
intermediate precision tests, showing recoveries between 70 and 120%, with RSD ≤
20% for most levels and pesticides. The method presented quantification limits of 10
µg kg-1
for most pesticides. The proposed method was applied to commercial samples
of potatoes and the occurrence of several pesticides was confirmed, including some
prohibited for the potato crop. Subsequently, the distribution of pesticides in the peel
and pulp was evaluated, indicating that some pesticides are concentrated in the peel
and others in the pulp, depending on the physicochemical properties of the pesticides.
The method was successfully applied to commercial samples and proved to be
effective for routine analyses.