title: Establishment of signal-recovery functions for calculation of recovery factor. Application to monitoring of contaminant residues in vegetables by chemiluminescence detection.
abstract: A new strategy is proposed for verifying if recovery factor is constant and independent of the real analyte content of samples. A signal-recovery function has been developed on the basis of measurement of spiked test samples before and after a pre-treatment step and considering, as starting point, a recent IUPAC recommendation which distinguishes between two terms--recovery factor, R, and apparent recovery, R*. Apparent recovery includes recovery factor and a new recovery term proposed in a previous paper by the authors, named calibration recovery, R(C). The signal-recovery function is obtained directly from the measured analytical signals instead of from the concentrations, simplifying the calculations. A linear signal-recovery curve indicates that the recovery factor is constant in the analyte concentration range studied experimentally and, in this way, a single recovery factor can be calculated. The usefulness of the proposed method has been shown by quantification of the pesticide carbaryl by two different flow-injection analysis methods with chemiluminescent detection based on the luminol and TCPO systems. Good results were obtained from both methods.
authors.affiliation: Department Analytical Chemistry, Faculty of Sciences, University of Granada, 18071, Granada, Spain. lgamiz@ugr.es
authors.forename: Laura
authors.initials: L
authors.lastname: Gámiz-Gracia
authors.forename: Luis
authors.initials: L
authors.lastname: Cuadros-Rodríguez
authors.forename: Jorge J
authors.initials: JJ
authors.lastname: Soto-Chinchilla
authors.forename: José F
authors.initials: JF
authors.lastname: Huertas-Pérez
authors.forename: Antonio
authors.initials: A
authors.lastname: González-Casado
authors.forename: Ana M
authors.initials: AM
authors.lastname: García-Campaña
mesh_terms: D005506:Food Contamination / Q000032:analysis*; D008163:Luminescent Measurements / Q000379:methods*; D014675:Vegetables / Q000737:chemistry*