title: Direct sample introduction gas chromatography and mass spectrometry for the determination of phthalate esters in cleaning products.
abstract: A method using direct sample introduction (DSI) coupled to gas chromatography-mass spectrometry (GC-MS) is developed for the determination of six phthalate esters (dimethyl, diethyl, dibutyl, butylbenzyl, diethylhexyl and dioctyl phthalate) in cleaning products. The different variables involved in the DSI step, including venting time and temperature, vaporisation time and temperature, injector heating temperature and gas flow rate and pressure, were evaluated and optimised using Taguchi orthogonal arrays. The proposed method, using calibration against methanolic standards, showed good linearity in the 0.05-15 μg g(-1) range and good repeatability, with RSD values ranging from 3.5% to 5.7%. Quantification limits between 0.010 and 0.041 μg g(-1), depending on the compound, were attained, while recovery assays provided values from 83% to 115%. Twenty-seven cleaning products were analysed using the DSI-GC-MS method, being four phthalates (dimethyl, diethyl, dibutyl and diethylhexyl phthalate) found in fourteen of them at concentration levels in the 0.1-21 μg g(-1) range. Compared with the most common GC injection technique, which uses the split/splitless injector, the proposed DSI procedure provided larger peak areas and lower detection limits, as result of the greater injected volume and reduction in noise.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, Regional Campus of International Excellence "Campus Mare Nostrum" University of Murcia, E-30100 Murcia, Spain.
authors.forename: J I
authors.initials: JI
authors.lastname: Cacho
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, Regional Campus of International Excellence "Campus Mare Nostrum" University of Murcia, E-30100 Murcia, Spain.
authors.forename: N
authors.initials: N
authors.lastname: Campillo
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, Regional Campus of International Excellence "Campus Mare Nostrum" University of Murcia, E-30100 Murcia, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Viñas
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, Regional Campus of International Excellence "Campus Mare Nostrum" University of Murcia, E-30100 Murcia, Spain. Electronic address: hcordoba@um.es.
authors.forename: M
authors.initials: M
authors.lastname: Hernández-Córdoba
mesh_terms: D003902:Detergents / Q000737:chemistry; D004051:Diethylhexyl Phthalate / Q000032:analysis; D004952:Esters; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D057230:Limit of Detection; D010795:Phthalic Acids / Q000032:analysis*; D013501:Surface-Active Agents / Q000737:chemistry*; D013696:Temperature
chemical_list: D003902:Detergents; D004952:Esters; D010795:Phthalic Acids; D013501:Surface-Active Agents; C032279:phthalic acid; D004051:Diethylhexyl Phthalate
keywords: Cleaning products; Direct sample introduction (DSI); Gas chromatography–mass spectrometry (GC–MS); Phthalate esters