A comparative study of the correction of systematic errors in the quantitation of pyrethroids in vegetables using calibration curves prepared using standards in pure solvent

Abstract

A comparative study of two mathematical approaches was performed in order to correct systematic errors due to the presence of the unexpected interferences which appear when the quantitation of the analyte in real samples is carried out with calibration curves built using standards in pure solvent. These methods consisted in the establishment of different mathematical expressions which transform the concentration (Cs) obtained using calibration graphs built using pure solvent into the corrected concentration (C(M)) that should be obtained if the quantitation is carried out with calibration curves built using standards dissolved in blank matrix extracts. In the two approaches the correction is performed from the results of an intermediate precision study which was carried out using both calibration graphs (prepared using pure solvent and blank matrix extract). By using ANCOVA to compare the slope of both solvent-based and matrix-matched calibration graphs, matrix effect was found in the determination of deltamethrin in tomato and acrinathrin in tomato and pepper. In these cases, both approaches led to good results.

Multicore Magnetic Nanoparticles Coated with Oligomeric Micelles: Characterization and Potential for the Extraction of Contaminants over a Wide Polarity Range

“…The potential interference of matrix components coeluting with aromatic amines was evaluated by comparing the slope of the calibration curve obtained from standards ( n = 8) with those obtained from sample extracts (textiles, wastewater, and urine), spiked with the analytes ( n = 5) at concentrations within the respective linear ranges. The differences for slope values were not statistically significant, the calculated p-values being above the critical value (0.05, Table S3 in the SI). Therefore, matrix components were not expected to interfere with the determination of the aromatic amines.…”

Dissipation of Pyrethroid Residues in Peppers, Zucchinis, and Green Beans Exposed to Field Treatments in Greenhouses: Evaluation by Decline Curves

“…Each fruit was cut in four pieces and two opposite quarters of each one were selected as a representative sample and were thoroughly mixed and divided into three subsamples. The samples were analyzed the same day of the collection to avoid problems of stability of the pyrethroids in the vegetable matrixes during the storage stage (10).…”

Efeito de matriz na quantificação de agrotóxicos por cromatografia gasosa

“…[79][80][81][82] Na Figura 6A, B e C estão representadas as curvas analíticas de análises cromatográficas de deltametrina em tomate, 77 thiametoxan em solo e batata. 83 Em cada gráfico, as curvas analíticas dos agrotóxicos foram obtidas em solventes puros e em extratos das matrizes.…”