title: Dilution standard addition calibration: A practical calibration strategy for multiresidue organic compounds determination.
abstract: Among calibration approaches for organic compounds determination in complex matrices, external calibration, based in solutions of the analytes in solvent or in blank matrix extracts, is the most applied approach. Although matrix matched calibration (MMC) can compensates the matrix effects, it does not compensate low recovery results. In this way, standard addition (SA) and procedural standard calibration (PSC) are usual alternatives, despite they generate more sample and/or matrix blanks consumption need, extra sample preparations and higher time and costs. Thus, the goal of this work was to establish a fast and efficient calibration approach, the diluted standard addition calibration (DSAC), based on successive dilutions of a spiked blank sample. In order to evaluate the proposed approach, solvent calibration (SC), MMC, PSC and DSAC were applied to evaluate recovery results of grape blank samples spiked with 66 pesticides. Samples were extracted with the acetate QuEChERS method and the compounds determined by ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Results indicated that low recovery results for some pesticides were compensated by both PSC and DSAC approaches. Considering recoveries from 70 to 120% with RSD <20% as adequate, DSAC presented 83%, 98% and 100% of compounds meeting this criteria for the spiking levels 10, 50 and 100μgkg(-1), respectively. PSC presented same results (83%, 98% and 100%), better than those obtained by MMC (79%, 95% and 97%) and by SC (62%, 70% and 79%). The DSAC strategy showed to be suitable for calibration of multiresidue determination methods, producing adequate results in terms of trueness and is easier and faster to perform than other approaches.
authors.affiliation: Laboratório de Análises de Resíduos de Pesticidas (LARP), Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria-RS, Brazil; Escola de Química e Alimentos, Universidade Federal do Rio Grande (FURG), 95500-000, Santo Antônio da Patrulha-RS, Brazil.
authors.forename: Manoel L
authors.initials: ML
authors.lastname: Martins
authors.affiliation: Laboratório de Análises de Resíduos de Pesticidas (LARP), Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria-RS, Brazil.
authors.forename: Tiele M
authors.initials: TM
authors.lastname: Rizzetti
authors.affiliation: Laboratório de Análises de Resíduos de Pesticidas (LARP), Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria-RS, Brazil.
authors.forename: Magali
authors.initials: M
authors.lastname: Kemmerich
authors.affiliation: Laboratório de Análises de Resíduos de Pesticidas (LARP), Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria-RS, Brazil.
authors.forename: Nathália
authors.initials: N
authors.lastname: Saibt
authors.affiliation: Laboratório de Análises de Resíduos de Pesticidas (LARP), Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria-RS, Brazil.
authors.forename: Osmar D
authors.initials: OD
authors.lastname: Prestes
authors.affiliation: Laboratório de Análises de Resíduos de Pesticidas (LARP), Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria-RS, Brazil.
authors.forename: Martha B
authors.initials: MB
authors.lastname: Adaime
authors.affiliation: Laboratório de Análises de Resíduos de Pesticidas (LARP), Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria-RS, Brazil. Electronic address: renato.zanella@ufsm.br.
authors.forename: Renato
authors.initials: R
authors.lastname: Zanella
mesh_terms: D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000592:standards; D009930:Organic Chemicals / Q000032:analysis* / Q000302:isolation & purification / Q000592:standards; D010573:Pesticide Residues / Q000032:analysis / Q000302:isolation & purification / Q000592:standards; D052616:Solid Phase Extraction; D012997:Solvents / Q000737:chemistry; D053719:Tandem Mass Spectrometry / Q000592:standards
chemical_list: D009930:Organic Chemicals; D010573:Pesticide Residues; D012997:Solvents
keywords: Calibration curves; Chromatography; Matrix effect; Multiresidue