Journal of Chromatography A, 1218 (2011) 3811–3815 Contents lists available at ScienceDirect Journal of Chromatography A journal homepage: www.elsevier.com/locate/chroma High performance thin layer chromatography determination of cellobiosan and levoglucosan in bio-oil obtained by fast pyrolysis of sawdust Catherine Tessini a , Mario Vega b , Niels Müller c , Luis Bustamante a , Dietrich von Baer a , Alex Berg c , Claudia Mardones a,∗ a Departamento de Análisis Instrumental, Facultad de Farmacia, Universidad de Concepción, Casilla 237, Correo 3, Concepción, Chile b Departamento de Bromatología, Facultad de Farmacia, Universidad de Concepción, Casilla 237, Correo 3, Concepción, Chile c Unidad de Desarrollo Tecnológico, Coronel, Universidad de Concepción, Casilla 4051, Correo 3, Concepción, Chile article info Article history: Received 6 October 2010 Received in revised form 6 April 2011 Accepted 11 April 2011 Available online 20 April 2011 Keywords: Levoglucosan Cellobiosan Bio-oil Pyrolysis HPTLC abstract In this work, high performance thin layer liquid chromatography (HTPLC) is applied to the determination of sugars in fast pyrolysis liquids (bio-oil) and fractions thereof. The proposed procedure allows the sepa- ration of anhydrosugar levoglucosan and cellobiosan, as well as glucose, arabinose, xylose and cellobiose. Pre-treatment and derivatization of samples are not necessary and volatile compounds present in bio-oil do not interfere with sugar analysis. The detrimental effect of the complex bio-oil matrix on columns and detector lifetime is avoided by using disposable HTPLC plates. Prior screening of glucose, present especially in aged and aqueous bio-oil fractions, is required to quantify cellobiosan without interference. Concentrations of levoglucosan and cellobiosan in bio-oil samples obtained from Pinus radiata sawdust were ranged between 1.27–2.26% and 0.98–1.96% respectively, while a bio-oil sample obtained from native wood contained a higher levoglucosan concentration. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Bio-oil, the liquid product of fast biomass pyrolysis, is attract- ing considerable interest as a renewable source of liquid fuels and chemicals. There are several methods for thermal biomass conver- sion. One of them is fast pyrolysis, which maximizes the yield of this liquid fuel [1]. It is a high-density fuel that can be transported and used by conventional systems like power generation turbines [2]. The biomass is decomposed to generate mostly vapors, aerosols and some charcoal. After cooling and condensation, a dark brown liquid is formed (crude bio-oil), with yields of up to 75 wt% (on a dry-feed basis) [1–5]. Characterization of bio-oil is a challenge and several analytical techniques must be applied to obtain a detailed product distribu- tion which is still incomplete. Only about 40% of bio-oil compounds can be quantified by gas chromatography (GC), especially volatile and thermostable compounds [6,7]. On the other hand, 10–15% polar and nonvolatile compounds have been determined by high performance liquid chromatography (HPLC) [6,7]. Such complex- ity requires laborious sample pre-treatment, including sequential extractions, and derivatization [7]. However, for the development ∗ Corresponding author. Tel.: +56 41 204252; fax: +56 41 226382. E-mail address: cmardone@udec.cl (C. Mardones). of bio-oil applications, simple and direct analytical methods for bio-oils and their fractions are preferred. The ‘sugar’ fraction of bio oil has particular interest as a fuel and as a source of chemicals. As chemical, levoglucosan (1,5-anhydro- -d-glucopyranose) and cellobiosan (1,6-anhydro--cellobiose) may have pharmaceutical applications, for example, in the syn- thesis of macrolide antibiotics [8]. The use of anhydrosugars in polymer production, non-ionic surfactants and non-hydrolysable polyglucose has also been described [9,10]. Due to the reactivity and sticking tendency [11], components of the ‘sugar fraction’ should be separated from the whole bio-oil to improve its fuel properties. Anhydrosugars present in bio-oil can be hydrolysed to cellobiose and glucose [11,12] and be used for ethanol production. The main compounds in the ‘sugar’ fraction are levoglucosan (Fig. 1A) and cellobiosan (Fig. 1B) with concentrations between 3–6% and 1–3%, respectively. Low concentrations of glucose, xylose, arabinose and cellobiose have also been reported [6]. The con- centrations of levoglucosan and cellobiosan, product of cellulose depolymerization, depend on pyrolysis conditions and the raw material employed, with maximum yields obtained at around 500 ◦ C. Pretreatments of biomass by hydrolysis or demineralization can substantially improve the yields of sugars [13]. For rough determination of ‘sugars’ in bio-oil, a method based on solvent fractionation of the water soluble fraction and analysis by refractive index has been proposed [11]. Levoglucosan deter- mination has been described using HPLC and especially GC/MS 0021-9673/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.chroma.2011.04.037