title: Matrix solid-phase dispersion combined to liquid chromatography-tandem mass spectrometry for the determination of paraben preservatives in mollusks.
abstract: A method for the extraction and determination of seven parabens, esters of 4-hydroxybenzoic acid, widely used as preservatives in personal care products, pharmaceuticals, etc., and two chlorinated derivatives (mono- and di-chloro methyl paraben) from mollusk samples was developed by combining matrix solid-phase dispersion (MSPD) and liquid chromatography-tandem mass spectrometry. MSPD parameters, such as solvent, solid support and clean-up sorbent, were optimized. Besides, since blank problems were observed for some parabens, these were investigated and blanks were tackled by precleaning all sorbents prior to use. Under final conditions, 0.5g of freeze-dried mollusk were dispersed with 1.2g of silica and packed into a cartridge containing 3g of C18, as on-line clean-up sorbent. This cartridge was eluted with 10mL of acetonitrile, evaporated and reconstituted in methanol for analysis. In the validation stage, successful linearity (R(2)>0.999), recoveries (between 71 and 117% for most analytes), precision (RSD lower than 21%) and limits of detection and quantification (LOD and LOQ, lower than 0.4 and 1.4ngg(-1) dry weight respectively) levels were achieved. Finally, the new methodology was applied to mussel, clam and cockle samples. Methyl paraben was above the LOQ in five of the six samples (not found in one clam sample) at concentrations up to 7ngg(-1) dry weight. Ethyl paraben was found above the LOQ in mussel and cockle samples at a concentration level around 0.3ngg(-1). n-Propyl paraben was only above the LOQ in one mussel sample.
authors.affiliation: Department of Analytical Chemistry, Nutrition and Food Science, IIAA-Institute for Food Analysis and Research, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
authors.forename: Eugenia
authors.initials: E
authors.lastname: Villaverde-de-Sáa
authors.affiliation: Department of Analytical Chemistry, Nutrition and Food Science, IIAA-Institute for Food Analysis and Research, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain. Electronic address: rosario.rodil@usc.es.
authors.forename: Rosario
authors.initials: R
authors.lastname: Rodil
authors.affiliation: Department of Analytical Chemistry, Nutrition and Food Science, IIAA-Institute for Food Analysis and Research, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
authors.forename: José Benito
authors.initials: JB
authors.lastname: Quintana
authors.affiliation: Department of Analytical Chemistry, Nutrition and Food Science, IIAA-Institute for Food Analysis and Research, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Cela
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D000818:Animals; D049872:Bivalvia / Q000737:chemistry / Q000378:metabolism; D049873:Cardiidae / Q000737:chemistry / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D057230:Limit of Detection; D008974:Mollusca / Q000737:chemistry* / Q000378:metabolism; D010226:Parabens / Q000032:analysis* / Q000302:isolation & purification; D011310:Preservatives, Pharmaceutical / Q000032:analysis* / Q000302:isolation & purification; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry
chemical_list: D000097:Acetonitriles; D010226:Parabens; D011310:Preservatives, Pharmaceutical; C032159:acetonitrile
keywords: 4-Hydroxybenzoic acid esters; Liquid chromatography-tripe quadrupole-tandem mass spectrometry (LC-QQQ-MS/MS); Mollusks; Sample preparation; Seafood