title: Determination of isothiazolinone preservatives in cosmetics and household products by matrix solid-phase dispersion followed by high-performance liquid chromatography-tandem mass spectrometry.
abstract: In this work, the development of a new efficient methodology applying, for the first time, matrix solid phase dispersion (MSPD) for the determination of sensitizer isothiazolinone biocides in cosmetics and household products - 2-methyl-3-isothiazolinone (MI), 5-chloro-2-methyl-3-isothiazolinone (CMI), 1,2-benzisothiazolinone (BzI) and 2-octyl-3-isothiazolinone (OI) - is described. The main factors affecting the MSPD extraction procedure, the dispersive phase and the elution solvent, are assessed and optimized through a multicategorical experimental design, using a real cosmetic sample. The most suitable extraction conditions comprise the use of 2g of florisil as dispersive phase and 5 mL of methanol as elution solvent. Subsequently, the extract is readily analyzed by HPLC-MS/MS without any further clean-up or concentration steps. Method performance was evaluated demonstrating to have a broad linear range (R(2)>0.9980) and limits of detection (LOD) and quantification (LOQ) at the low nanogram per gram level, which are well below the required limits for UE regulation compliance. Satisfactory recoveries above 80%, except for MI (mean values close to 60%), were obtained. In all cases, the method precision (% RSD) was lower than 7%, making this low cost extraction method reliable for routine control. The validated methodology was finally applied to the analysis of a wide variety of cosmetics and household products. Most of the real samples analyzed have been shown to comply with the current European Cosmetic Regulation, although the results obtained for some rinse-off cosmetics (e.g. baby care products) revealed high isothiazolinone content.
authors.affiliation: Department of Analytical Chemistry, Nutrition and Food Science, Faculty of Chemistry, Campus Vida, University of Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Alvarez-Rivera
authors.forename: Thierry
authors.initials: T
authors.lastname: Dagnac
authors.forename: Marta
authors.initials: M
authors.lastname: Lores
authors.forename: Carmen
authors.initials: C
authors.lastname: Garcia-Jares
authors.forename: Lucia
authors.initials: L
authors.lastname: Sanchez-Prado
authors.forename: J Pablo
authors.initials: JP
authors.lastname: Lamas
authors.forename: Maria
authors.initials: M
authors.lastname: Llompart
mesh_terms: D000704:Analysis of Variance; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003358:Cosmetics / Q000737:chemistry*; D004202:Disinfectants / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D016014:Linear Models; D011310:Preservatives, Pharmaceutical / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012915:Soaps / Q000737:chemistry; D052616:Solid Phase Extraction / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods; D013844:Thiazoles / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D003358:Cosmetics; D004202:Disinfectants; D011310:Preservatives, Pharmaceutical; D012915:Soaps; D013844:Thiazoles