Journal of Chromatography A, 1216 (2009) 3398–3401 Contents lists available at ScienceDirect Journal of Chromatography A journal homepage: www.elsevier.com/locate/chroma Short communication Biogenic amine determination in wines using solid-phase extraction: A comparative study A. Pe ˜ na-Gallego, P. Hernández-Orte ∗ , J. Cacho, V. Ferreira Department of Analytical Chemistry, School of Sciences, University of Zaragoza, Plaza San Francisco s/n, 50009 Zaragoza, Spain article info Article history: Received 18 September 2008 Received in revised form 22 January 2009 Accepted 29 January 2009 Available online 5 February 2009 Keywords: Liquid chromatography Fluorescence detection Solid-phase extraction Mixed bed Biogenic amines Wine samples abstract Biogenic amines in wine usually are analyzed by high-performance liquid chromatography after direct derivatization. A method of isolation based on solid-phase extraction (SPE) with mixed-mode resins (Oasis MCX, reverse-phase and ion exchange) was developed. The different stages of the isolation process (load- ing, elution and washing) were optimized to obtain a simple procedure that yields a clean chromatogram. The relative standard deviation (%RSD) of the retention times and relative areas was less than 0.3% and 6%, respectively. Limits of quantification were lower than 0.16mgL -1 for all the amines and the linear range of concentration was 0.16–8 mg L -1 for putrescine, cadaverine and tyramine, and up to 10 mg L -1 for histamine. © 2009 Elsevier B.V. All rights reserved. 1. Introduction The analytical determination of biogenic amines and polyamines is not an easy task due to their structure and generally low con- centrations present in complex matrices. High-performance liquid chromatography (HPLC) is the technique most often used to deter- mine these amines. However, biogenic amines do not have good absorption properties in the visible, ultraviolet, or fluorescent wavelength ranges. For that reason, chemical derivatization prior to HPLC is used to reach the levels of selectivity and sensitivity required for determination [1,2]. A large number of studies have been made of biogenic amine determination using pre- and post-column derivatization. The reagents most often used are dansyl chloride [3,4], o-phthaldi- aldehyde [4–6] and 6-aminoquinolyl-N-hydrosysuccinimidyl car- bamate (AQC) [7–11], which produce fluorescent derivatives. Pentafluorobenzaldehyde is used as reagent to derivative biogenic amines in wines and analyze while GC–MS [12]. Lately, there has been a growing interest in the use of electrospray ionization-mass spectrometry (ESI-MS). ESI provides an effective means for ioniz- ing analytes directly from solution prior their MS analysis without a previous derivatization step [13,14]. Almost all the methods used in amine analysis are direct methods without previous sample treatment. The resulting chro- ∗ Corresponding author. Tel.: +34 976 762503; fax: +34 976 761292. E-mail address: puhernan@unizar.es (P. Hernández-Orte). matograms are complex because wine contains compounds with aminated groups that react with the derivatizing agent to produce fluorescent derivatives. It is important, therefore, to develop new methods of biogenic amine determination after preliminary SPE cleaning stages. Molins-Legua and Campins-Falco [15] reviewed the literature on different cleaning methods (C18, LiChrolut EN, and ion-exchange resin). Their study showed that none of these resins is ideal for the single-stage quantification of all amines. The purpose of this study was to develop an SPE (mixed-mode ion-exchange and reverse-phase) method to be used before ana- lyzing histamine, putrescine, tyramine, and cadaverine in wines in order to avoid interferences. The amines isolated were derivatized with AQC and analyzed with HPLC. The linearity, repeatability, accu- racy, percentage of recovery, detection and quantification limits for the proposed method were determined. 2. Experimental 2.1. Standard solutions and wine samples The amine standards were prepared by dissolving pure com- pounds in methanol (2 g L -1 ). Amine solutions were prepared from the standard solution by dilution in water. Wines of diverse types (synthetic, young, vintage, oxidized, defective) were used in the study. The synthetic wine was an aqueous solution, pH 3.5, con- taining 10% (v/v) ethanol and 5 g L -1 of tartaric acid. In the direct analysis method, we started with a 1 mL sample of wine, which was centrifuged at 4500 rpm for 15 min and then ultra- 0021-9673/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.chroma.2009.01.106