| dc.description.abstract | In recent years, the indiscriminate use of pesticides and non-adoption of good
agricultural practices have been evidenced by the results of analysis of pesticide
residues in food, such as sweet pepper, one of Brazilian record holders with active
ingredients that are banned or above the recommended limits. Thus, the present
study aimed to develop and validate a rapid method for the determination of 83
pesticides in sweet pepper using modified QuEChERS method and Ultra-high
Performance Liquid Chromatography coupled to tandem Mass Spectrometry
(UHPLC-MS/MS). In the sample preparation extraction/partition procedures, and
different sorbents for clean-up were tested, such as diatomaceous earth and
polymeric sorbent. It was used the 24 factorial design for optimization of the method
of extraction, which consisted of the extraction of 10.0 g sweet pepper with 10.0 mL
of acetonitrile. In the partition step 1.5 g of NaCl, 4.0 g MgSO4 were added, carrying
out shaking and centrifugation. It was carried out the clean-up step of 1.0 ml of
extract with 40.0 mg of PSA and 150.0 mg of MgSO4, followed by shaking and
centrifugation. The extract was filtered, diluted and analyzed by UHPLC-MS/MS.
Most compounds showed linear range (r2 ≥ 0.99).The matrix effect was compensed
by using analytical curves prepared in blank matrix-matched. The accuracy of the
method was verified by testing recovery at four concentration levels, yielding values
between 70.0 and 120.0% for most compounds evaluated. Values of LODm and
LOQm were 3 or 7.5 μg kg-1 and 10 or 25 μg kg-1, respectively. RSD values lower
than 20% ensured good precision of the method. The method was performed on 20
samples of sweet pepper, in which residues of acetamiprid, azoxystrobin, boscalid,
carbendazim, chlorpyrifos ethyl, clothianidin, difenoconazole, fenpropathrin,
pyraclostrobin and pyrimethanil were quantified in concentrations ranging from 10 to
294 μg kg-1. The proposed modified QuEChERS method for the determination of 81
from 83 pesticide residues in sweet pepper using UHPLC-MS/MS shown to be
effective and can be applied in routine analysis. | |
