Carbohydrate Polymers 93 (2013) 184–190 Contents lists available at SciVerse ScienceDirect Carbohydrate Polymers j ourna l ho me pag e: www.elsevier.com/locate/carbpol Synthesis of alkylated potato starch derivatives and their potential in the aqueous solubilization of benzo[a]pyrene Ana-Maria Rosu a,b,c , Catherine Rafin a,b,∗ , Gheorghe Surpateanu c , Gheorghe Brabie d , Doru Neculai Miron c , Etienne Veignie a,b a Univ Lille Nord de France, Lille 59000, France b ULCO, Unité de Chimie Environnementale et Interactions sur le Vivant, Dunkerque 59140, France c University ‘Vasile Alecsandri’ of Bacau, Faculty of Engineering, Department of Food Products Engineering, Bacau 600115, Romania d University ‘Vasile Alecsandri’ of Bacau, CCIMT Centre of Research, Faculty of Engineering, Bacau 600115, Romania a r t i c l e i n f o Article history: Received 16 November 2011 Received in revised form 23 May 2012 Accepted 11 June 2012 Available online 29 June 2012 Keywords: Benzo[a]pyrene Potato starch Etherification Esterification Amphiphile a b s t r a c t For the development of renewable bioproducts able to solubilize organic persistent pollutant such as benzo[a]pyrene (BaP), modified potato starch was synthesized by alkylation. The addition of alkyl chains was performed with three different alkylation agents: epoxyalkane, alkenyl succinic anhydride and 1,4- butane sultone. Twelve alkylated starches were obtained with different molar substitutions (MS) and various alkyl chain lengths (to three carbons up to sixteen). The chemical structural characteristics were investigated by methods of 1 H NMR and FTIR. In comparison with the native starch, the ether modi- fied starches showed in general an enhancement of their aqueous solubility whereas the ester modified starches stimulated the BaP aqueous solubilization. Indeed, the compounds P6 and P12, which increased 40-fold the BaP aqueous concentration, present high surfactant properties. © 2012 Elsevier Ltd. All rights reserved. 1. Introduction Polycyclic aromatic hydrocarbons (PAHs) are very toxic chem- ical compounds in the environment which were identified as carcinogenic and mutagenic compounds (White, 1986). PAHs, espe- cially high molecular weight ones such as benzo[a]pyrene (BaP), tend to persist in the environment because of their low water solubility and their tendency to be absorbed onto soil organic mat- ter (Cerniglia, 1992; Wilson & Jones, 1993). Among the processes available for soil rehabilitation, the surfactant-enhanced remedi- ation has been suggested as a promising remediation technology (Mulligan, Yong, & Gibbs, 2001; Zhu & Zhang, 2010). Desorption enhancement of hydrophobic organics from soil by surfactants is the key principle of the surfactant washing process. A surfac- tant containing both hydrophobic and hydrophilic portions can effectively enhance the aqueous solubility of hydrophobic organics by partitioning them into the hydrophobic core. Such surfactants could be used in pre-treatment washing of soil contaminated with PAHs in order to transfer them into the aqueous solution (Mulligan et al., 2001). This is a prerequisite to stimulate the first steps of PAHs oxidation (Flotron, Delteil, Padellec, & Camel, 2005) which is one of the most limiting factors for PAHs degradation by chemical ∗ Corresponding author at: ULCO, Unité de Chimie Environnementale et Interac- tions sur le Vivant, Dunkerque 59140, France. Tel.: +33 03 28 65 82 78. E-mail address: rafin@univ-littoral.fr (C. Rafin). or/and biological processes (Rafin, Veignie, Fayeulle, & Surpateanu, 2009; Rosu, Veignie, Surpateanu, Brabie, Miron, & Rafin, 2011). For this purpose, polysaccharides in particular modified biopolymers derived from chitin and starch could be used (Crini, 2005; Dias, Hussain, Marcos, & Roque, 2011; Zhu & Zhang, 2010). These polysaccharides which are abundant, renewable and biodegradable resources, have been more and more investigated as potential adsorbents materials for removing pollutants from con- taminated water (Crini, 2005; Kim & Lim, 1999). Nevertheless, the weak aqueous solubility of starch is also known to be a major constraint that seriously limits the development of starch-based materials. For non-food uses, starch is generally modified in order to obtain products with properties suitable for various and searched applications (Wesslén & Wesslén, 2002). The aims of the present work were to synthesize potato starch derivatives either by esterification or by etherification in order to fulfill two main objectives: firstly to increase the aqueous solubility of modified starch and secondly to allow BaP solubilization permit- ting therefore its retention in polysaccharide-based materials. 2. Materials and methods 2.1. Chemicals The materials used were as follows: benzo[a]pyrene (BaP) at 96% HPLC purity was purchased from Fluka (St. Quentin Fallaviers, 0144-8617/$ – see front matter © 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.carbpol.2012.06.062