The sample matrix can cause an enhancement in the chromatographic response for pesticide residues in a matrix extract by
comparison with the same concentration in a solvent solution.
Matrix type, ratio of matrix to analyte concentration, the injector
type and the temperature can affect the enhancement values [25].
The slopes of standard curves constructed in acetonitrile and in
the extracts may serve as an indicator of the matrix effect (ME (%)).
When the slope of the analytical curve prepared by spiking blank
matrices extract with known amounts of pesticides was compared
with the slope of the analytical curves prepared in acetonitrile,
higher enrichment of the signals was found for the fish liver
matrix (450%). For the hepatopancreas matrix, no significant
matrix effect (o10%) was found. Results show that the use of a
simple external standard calibration method may produce erroneous results in the quantification of pesticides in these samples.
In this study, to solve this problem, a matrix matched calibration
was used for improving the accuracy of the quantification.