Contents lists available at ScienceDirect
journal homepage: www.elsevier.com/locate/foodchem
Determination of phthalate sum in fatty food by gas chromatography
ˇ ´ Ivan Ostrovsky a, Radomír Cabala b, Róbert Kubinec a,*, Renáta Górová a, Jaroslav Blaško a, Janka Kubincová c, ˇ imnácová b, Wilhelm Lorenz d ˇ Lucie Ra
Comenius University, Faculty of Natural Sciences, Institute of Chemistry, Mlynská dolina CH-2, Bratislava 84215, Slovak Republic Charles University in Prague, Faculty of Science, Department of Analytical Chemistry, Albertov 6, Prague 2, Czech Republic c Technological Department Biocentre, Food Research Institute, Kostolná 5, Modra, Slovak Republic d Martin-Luther University, Halle-Wittenberg,Department of Chemistry, Institute of Analytical and Environmental Chemistry, Halle, Saale, Germany
a r t i c l e
i n f o
a b s t r a c t
Presented method for determination of sum of phthalates is based on their alkaline hydrolysis to phthalic acid at 80 °C for 20 h, followed by the selective extraction of lipophilic interferents from acidiﬁed hydrolysate at pH 1 with n-hexane.Phthalic acid is derivatized to dimethyl phthalate (DMP) with diazomethane in aqueous-chloroform two-phase system. Resulting DMP is absorbed in chloroform and determined by GC-FID. Method calibration resulted in LOD and LOQ of 0.4 (2.1) and 1.2 (6.2) lg gÀ1 (nmol gÀ1) DMP, respectively. Real samples of Baltic herring and codﬁsh, butter, pork, goose and duck fats, sunﬂower, olive, rapeseed and linseedoils were analysed and the background corrected total phthalates content was found in the range from not detected level in duck fat to 12.5 (64.3) lg gÀ1 (nmol gÀ1) in butter, respectively. Ó 2010 Elsevier Ltd. All rights reserved.
Article history: Received 4 December 2008 Received in revised form 5 February 2010 Accepted 9 June 2010
Keywords: Total phthalates Phthalic acid Dimethyl phthalateFish Vegetable oil
1. Introduction Phthalates (PHTs) are by far one of the most ubiquitous chemicals worldwide including environment. Over one million tons of PHTs are produced in Western Europe each year therefore they are regular part of environment and human food chain as well. The food control is limited to some aspects and chemical analysis and toxicological evaluation are often thebottleneck (Grob, 2008). The legislative requirements are often limited to only several mostly used PHTs such as di-2-ethylhexyl phthalate (DEHP), di-n-butyl phthalate (DBP), di-n-octyl phthalate (DOP) and butylbenzyl phthalate (BBP) in water, food and selected commercial products (Council Directive 88/378/EEC, 1988; Council Regulation EEC 793/93, 1993; Directive 2005/84/EC, 2005; PhthalatesInformation Centers Europe and USA, 2008). Risk assessments of only several PHTs have been completed where those for diisononyl phthalate (DINP) and diisodecyl phthalate (DIDP) show no risks to human health or environment for any current use. Risk assessments for other PHTs remain open as scientiﬁc data are still being considered (Ofﬁcial Journal of the European Union, 2006). In other words, there is stilla need for their monitoring in the environment and especially in human food chain. Industry uses mixtures of PHTs in order to provide a wide range of different properties for different uses (Staples, Peterson, Parker* Corresponding author. Tel.: +421 2 602 96 330. E-mail address: email@example.com (R. Kubinec). 0308-8146/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved.doi:10.1016/j.foodchem.2010.06.045
ton, & Adams, 1997). Thousands of PHTs isomers are produced by reaction of 1,2-benzenedicarboxylic (ortho-phthalic) and 1,4-benzenedicarboxylic (terephthalic) acid with a mixture of alcohols, typically from methanol up to tridecanol. There is basic discrepancy between the legislative requirements to determine concentration of several selected PHTs and the concentration...