Please cite this article in press as: T. Le, et al., Dispersive magnetic immunoaffinity extraction. Anatoxin-a determination, J. Chromatogr. A (2017), https://doi.org/10.1016/j.chroma.2017.10.076 ARTICLE IN PRESS G Model CHROMA-358981; No. of Pages 6 Journal of Chromatography A, xxx (2017) xxx–xxx Contents lists available at ScienceDirect Journal of Chromatography A journal homepage: www.elsevier.com/locate/chroma Dispersive magnetic immunoaffinity extraction. Anatoxin-a determination  Tinh Le a , Francesc A. Esteve-Turrillas a,∗ , Sergio Armenta a,∗ , Miguel de la Guardia a , Guillermo Qui ˜ nones-Reyes b , Antonio Abad-Fuentes b , Antonio Abad-Somovilla c a Department of Analytical Chemistry, University of Valencia, 50th Dr. Moliner St., 46100 Burjassot, Spain b Institute of Agrochemistry and Food Technology, Consejo Superior de Investigaciones Científicas (IATA-CSIC), 7th Agustín Escardino Av., 46980 Paterna, Spain c Department of Organic Chemistry, University of Valencia, 50th Dr. Moliner St., 46100 Burjassot, Spain a r t i c l e i n f o Article history: Received 18 September 2017 Received in revised form 19 October 2017 Accepted 31 October 2017 Available online xxx Keywords: Anatoxin-a Cyanobacteria Antibody Magnetic Immunoaffinity Ion mobility spectrometry a b s t r a c t Specific monoclonal antibodies were coupled with magnetic Sepharose-based beads and used, for the first time. The methodology was applied to preconcentrate anatoxin-a from water and the later determination by ion mobility spectrometry (IMS). Dispersive magnetic immunoaffinity (d-MagIA) extraction method- ology provided a limit of detection of 0.02 g L −1 and a satisfactory precision with a relative standard deviation lower than 15%. Recoveries were evaluated at 0.5, 1.0 and 5.0 g L −1 anatoxin-a with quanti- tative values from 91 to 115%. Additionally, isobaric interferences with phenylalanine were completely avoided by the use of the developed d-MagIA extraction coupled to IMS determinations. © 2017 Elsevier B.V. All rights reserved. 1. Introduction Sample pretreatment is usually the weakest link of the analyti- cal chain, providing till 60% of error sources of the whole procedure and consuming around 60–70% of the analysis time [1]. Solid phase extraction (SPE) is the most popular sample pretreatment method for liquid samples due to its many significant advantages, such as easiness for automation, reproducibility, and high-throughput capability [2,3]. Since its introduction, there have been significant improvements in the sorbents employed in SPE [4] and in the available formats [5] including the development of related extrac- tion techniques such as micro-extraction by packed sorbent [6], stir-bar sorptive extraction [7], solid-phase micro-extraction [8], and dispersive-SPE [9], among others. The role of the sorbent in dispersive-SPE is the retention of matrix components while the analytes remain in the liquid phase, or alternatively, the reten- tion of the analytes in the particles and the later separation from  Selected paper from the 19th International Symposium on Advances in Extrac- tion Technologies (ExTech 2017), 27–30 June 2017, Santiago de Compostela, Spain. ∗ Corresponding authors. E-mail addresses: francesc.a.esteve@uv.es (F.A. Esteve-Turrillas), sergio.armenta@uv.es (S. Armenta). the matrix by centrifugation or filtration, which involves several minutes [10]. This drawback can be overcome using paramagnetic sorbents dispersed in the solution to adsorb the target analytes, which can be easily separated from the solution by an external magnet. This method is usually known as dispersive magnetic SPE (d-MSPE) and it provides an easy and fast extraction of the analytes from the liquid sample [10]. The development of novel sorbents for d-MSPE with improved capabilities such as high sorption capacity, high surface area, stabil- ity, or selectivity is an active research field. In this sense, magnetic particles have been coated with silica [11], octadecylsilane [12], carbon nanotubes [13], graphene [14], molecularly imprinted poly- mers [15], and metal-organic-frameworks [16] among others. Immunosorbents have been previously used for the selective extraction and enrichment of organic compounds by SPE [17], in the so-called immunoaffinity chromatography (IAC). Antibody- immobilized magnetic beads have been previously employed in the immunoprecipitation of chromatin or proteins, but in our knowl- edge the use of antibodies in magnetic-like formats for sample extraction has not been explored yet. Thus, the aim of this paper is the synthesis of magnetic particles coated with antibodies and their use for the first time as dispersive magnetic immunoaffinity https://doi.org/10.1016/j.chroma.2017.10.076 0021-9673/© 2017 Elsevier B.V. All rights reserved.