Journal of Chromatography A, 1049 (2004) 155–160 Determination of organochlorine pesticide residues in honey from the central zone of Portugal and the Valencian community of Spain  C. Blasco b , C.M. Lino a,∗ , Y. Pic´ o b , A. Pena a , G. Font b , M.I.N. Silveira a a Celeste de Matos LINO, Group of Bromatology—CEF, Laboratory of Bromatology, Faculty of Pharmacy, University of Coimbra, 3000-295 Coimbra, Portugal b Laboratori de Bromatologia i Toxicologia, Facultat de Farm` acia, Universitat de Val` encia, Burjassot, Val` encia, Spain Received 8 March 2004; received in revised form 30 June 2004; accepted 15 July 2004 Abstract In this study nine organochlorine pesticide residues (-, -, and -hexachlorocyclohexane (HCH), hexachlorobenzene (HCB), aldrin, p,p  -DDE, p,p  -DDD, o,p  -DDT, and p,p  -DDT) in forty nine samples of honey collected from markets of Portugal and Spain during 2001 and 2002, respectively, were evaluated. For this evaluation, three analytical procedures were studied. The analytical procedure, based on LLE extraction with ethyl acetate followed by gas chromatography–electron-capture detection (GC–ECD) for quantification, and mass spectrometry (GC–MS) for confirmation, has been selected. Recoveries of spiked samples ranged from 68%, for -HCH, and 126% for p,p  -DDT, for fortification levels between 10 and 100 g/kg, and 64%, for -HCH, and 143% for -HCH for fortification levels between 20 and 200 g/kg. Limits of quantification, using GC–ECD, were from 0.01 and 0.10 mg/kg, and limits of detection between 0.001 and 0.02mg/kg. Fourteen Valencian samples were contaminated, containing residues of HCB or/and HCH isomers. The frequency of detection was 56% for Spanish samples. In Portugal, 23 samples were contaminated, what means 95.8%. In Spanish samples, concentrations range from nd to 0.03 mg/kg for HCB, and nd to 2.24 mg/kg for HCH-total. The mean concentration and standard deviation were 0.017 ± 0.011 mg/kg for HCB, and 0.579 ± 0.747 mg/kg for HCH-total, contributing the  isomer with the highest values. The samples from Portugal showed higher levels. Levels of HCB ranged from nd to 0.39 mg/kg. HCH-total ranged from nd to 4.86 mg/kg, and DDT-total from nd to 0.658 mg/kg. Mean concentration and standard deviation were 0.09 ± 0.116 mg/kg for HCB, 1.357 ± 1.30 mg/kg for HCH-total, and 0.143 ± 0.193 mg/kg for DDT-total. © 2004 Elsevier B.V. All rights reserved. Keywords: Organochlorine; Pesticides 1. Introduction The occurrence of organochlorine compounds in the food chain has already been reported in several studies. This class of organic compounds constitutes one of the most important groups of dangerous organic contaminants. The environ- mental contamination by persistent organochlorine pesticide  Presented at the 3rd Meeting of the Spanish Association of Chromatog- raphy and Related Techniques and the European Workshop: 3rd Waste Water Cluster, Aguadulce (Almeria), 19–21 November 2003. ∗ Corresponding author. Tel.: +351 239859994; fax: +351 239827126. E-mail address: cmlino@ci.uc.pt (C.M. Lino). (OCPs) residues has been widely documented in several countries, such as Portugal and Spain in medicinal plants, water, milk, and biological fluids [1–4]. Due to its lipophilic nature, OCPs enter into the food chain by accumulating in fats, but can also be present in non-fatty products, even those which have not been treated directly with them [5]. They can be present in honey because of the plant treatment or by migration from wax to honey. Since honeybees travel long distances and come close to many plants, honey may be an easily accessible environmental pollution indicator [6,7]. Pesticide determination in bee products is necessary to monitor contamination and guarantee consumer health [7]. Honey is a natural product that must be free of any chemical 0021-9673/$ – see front matter © 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.chroma.2004.07.049