Journal of Chromatography B, 870 (2008) 17–21 Contents lists available at ScienceDirect Journal of Chromatography B journal homepage: www.elsevier.com/locate/chromb Determination of cyanide and volatile alkylnitriles in whole blood by headspace solid-phase microextraction and gas chromatography with nitrogen phosphorus detection Pere Boadas-Vaello a , Eric Jover b,∗ , Jordi Llorens a , Josep M. Bayona b a Departament de Ci` encies Fisiol` ogiques II, Universitat de Barcelona-IDIBELL, Feixa Llarga s/n, E-08907 L’Hospitalet de Llobregat, Catalonia, Spain b Environmental Chemistry Department, IIQAB-CSIC, Jordi Girona 18-26, E-08034 Barcelona, Catalonia, Spain article info Article history: Received 29 October 2007 Accepted 6 May 2008 Available online 24 May 2008 Keywords: Headspace Headspace-SPME GC-NPD Volatile alkylnitriles Cyanide Crotononitrile Allylnitrile abstract Simultaneous determination of cyanide and volatile alkylnitriles such as acetonitrile, cis- and trans- crotononitrile, allylnitrile and butyronitrile at low ppb concentration on whole blood (rat and mice) by headspace solid-phase microextraction (HS-SPME) followed by gas chromatography (GC) with nitrogen phosphorus detection has been achieved for the first time. SPME extraction time and temperature were optimized using a star experimental design. Optimum conditions for cyanide extraction were chosen to analyze unspiked blood samples containing alkylnitriles as that analyte occurs at the lowest concentra- tions. For all analytes, the developed methodology yielded good quality parameters. In all cases, good reproducibility (relative standard deviation ≤12%), detection limits (<3 ng mL -1 ) and quantification limits (<4 ng mL -1 ) were recorded. © 2008 Elsevier B.V. All rights reserved. 1. Introduction Alkylnitriles are widespread organic compounds of both natu- ral and synthetic origin being used in many technical applications. Nevertheless, a variety of toxic effects in mammalian species have been reported. Indeed, the metabolic breakdown of the parent nitrile by enzymatic activities within the organism releases free cyanide. Then cyanide impairs the energy metabolism of cells caus- ing acute lethality [1,2]. In addition, neurotoxic properties have been reported for a number of nitriles, including the unsaturated 4- carbon alkylnitriles namely, allylnitrile (ALN) [3], cis-crotononitrile (CCN) [4] and trans-crotononitrile (TCN) [5,6] whereas butyroni- trile (BTN) does not share those effects. The kind of toxic effects caused by nitriles may thus vary greatly as a function of their pre- cise chemical structure, so their toxicological evaluation requires understanding of the structure–activity relationship. Major issues in this relationship are the rate at which nitriles are metabolized to cyanide in vivo, and the identity of the enzymes catalyzing that metabolism [7,8]. Elucidation of these questions often requires obtaining blood concentration data for both the parent compound and its metabolite. ∗ Corresponding author. Tel.: +34 934006100; fax: +34 932045904. E-mail address: ejcqam@iiqab.csic.es (E. Jover). Cyanide has been analyzed in blood using different analytical techniques. One earlier and widely used method is based on the Conway microdiffusion cells where the acidified cyanide migrates to an alkaline solution which is determined by colorimetric [8,9], fluorimetric [10] or electrometric methods [11]. More recently, it has been carried out including a separation step coupled to a detec- tion technique such as high performance liquid chromatography coupled to a fluorimetric detection [12] or capillary electrophoresis coupled to an ultraviolet detector [13]. Moreover, gas chromatogra- phy (GC) coupled to electron capture detector has been increasingly used following a derivatization step [14,15], headspace GC cou- pled to electron capture detector [16,17] or nitrogen-phosphorus detector (NPD) [18,19] and solid-phase microextraction (SPME) GC combined with NPD [19,20] or mass spectrometry [21]. Neverthe- less, only a limited number of studies have been carried out for alkylnitriles determination in whole blood and to the best of our knowledge only one work deals with the simultaneous determina- tion of cyanide and volatile alkylnitriles using headspace-GC-NPD [22]. However, in order to understand the metabolic pathways for different alkylnitriles, trace level determination of the parent com- pound and its metabolites should be undertaken. The aim of this work was to optimize the determination of free cyanide and different alkylnitriles using SPME GC-NPD in whole blood matrix for use in experimental toxicity studies. SPME tech- nique has proven to be a suitable technique for the determination 1570-0232/$ – see front matter © 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.jchromb.2008.05.031