Journal of Chromatography A, 1217 (2010) 6449–6454 Contents lists available at ScienceDirect Journal of Chromatography A journal homepage: www.elsevier.com/locate/chroma A simple hollow fiber renewal liquid membrane extraction method for analysis of sulfonamides in honey samples with determination by liquid chromatography–tandem mass spectrometry Gizelle Cristina Bedendo a , Isabel Cristina Sales Fontes Jardim b,c , Eduardo Carasek a,d,∗ a Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC, Brazil b Institute of Chemistry, University of Campinas, 13083-970 Campinas, SP,Brazil c Instituto Nacional de Ciências e Tecnologias Analíticas Avanc ¸ adas, P.O. Box 6154, Campinas, SP, Brazil d Instituto Nacional de Ciência e Tecnologia de Bioanalítica, P.O. Box 6154, 13083-970 Campinas, SP, Brazil article info Article history: Received 14 June 2010 Received in revised form 9 August 2010 Accepted 11 August 2010 Available online 24 August 2010 Keywords: Hollow fiber renewal liquid membrane (HFRLM) Polypropylene membrane Sulfonamides LC–MS/MS abstract A sensitive and precise analysis using hollow fiber renewal liquid membrane (HFRLM) extraction followed by high performance liquid chromatography–tandem mass spectrometry (LC–MS/MS) is described for determination of five sulfonamides in honey samples. In this procedure, the organic solvent introduced directly into the sample matrix extracts the sulfonamides and carries them over the polypropylene porous membrane. An organic solvent is immobilized inside the polypropylene porous membrane, leading to a homogeneous phase. The stripping phase at higher pH in the lumen of the membrane promotes the ionization of the target compounds releasing them to this phase. The most important parameters affecting the extraction efficiency were optimized by multivariable designs (pH and sample mass, pH and buffer for stripping phase, extraction temperature and time, type and volume of extractor solvent and use of salt to saturate the sample). Detection limits in the range of 5.1–27.4 g kg -1 and linearity coefficient of correlation higher than 0.987 were obtained for the target analytes. The results obtained for the proposed method show that HFRLM–LC–MS/MS can be used for determination of the five sulfonamides studied in honey samples with excellent precision, accuracy, practicality and short analysis time. © 2010 Elsevier B.V. All rights reserved. 1. Introduction According to European Council Directive 2001/110/EC, honey is a natural sweet substance produced by bees (Apis mellifera) from nectar of plants, secretions of living parts of plants, or excretions of plant-sucking insects on the living parts of plants. The bees col- lect these materials and transform them by combining them with specific substances of their own. After, deposit, dehydrate, store and leave them in honeycombs to ripen and mature [1]. Chemi- cally speaking, honey is a highly hygroscopic and very concentrated aqueous solution of sugars. As an analytical sample, honey is a very complex matrix. Its composition depends strongly on the plant species from which the nectar or honeydew was collected, and other factors such as environmental conditions and climate [2]. Because of its rich composition, honey presents appreciable value for human health. However, these benefits can be reduced due to the presence of toxins, pollutants and contaminants intro- ∗ Corresponding author. Tel.: +55 48 37216844; fax: +55 48 37216845. E-mail address: carasek@qmc.ufsc.br (E. Carasek). duced during its manipulation or coming from the environment due to agriculture or apiculture. Honey can be contaminated in a direct way (contaminants like pesticides, pharmaceutical residues, acaricides, bee repellents, wood protectants and wax foundations coming from beekeeping) or in an indirect way (contaminants like pesticides, polychlorinated biphenyls, bacteria, heavy met- als, polyaromatic hydrocarbons and radionuclides coming from agriculture practices or the environment in general) [2]. Among the direct contaminants are those that belong to several pharma- ceutical classes, where antibiotics such as the sulfonamides are including. The sulfonamide residue determination in food is of concern because of their potential carcinogenic character and the possibility of development of antibiotic resistance in humans [3]. Different analytical methods based on a Purospher Star RP- 18ec column with fluorescence (RP-HPLC-FL) or by tandem mass spectrometry (RP-LC–ESI-MS/MS) detection has been reported for determining residues of sulfonamides in food samples. Most of these methods involve a pretreatment with hydrolysis followed by solid phase extraction (SPE). However, these techniques are consid- ered expensive and laborious, and frequently result in high blank levels, i.e., high noise signal to blank samples, causing ionic suppres- 0021-9673/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.chroma.2010.08.030