Short communication Quantifying fenobucarb residue levels in beef muscles using liquid chromatography–tandem mass spectrometry and QuEChERS sample preparation Ki Hun Park a , Jeong-Heui Choi b , A.M. Abd El-Aty c,⇑ , Md. Musfiqur Rahman a , Jin Jang a , Ah-Young Ko a , Ki Sung Kwon d , Hee Ra Park d , Hyung Soo Kim d , Jae-Han Shim a,⇑ a Natural Products Chemistry Laboratory, Biotechnology Research Institute, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 500-757, Republic of Korea b Institute of Environmental Research (INFU), Faculty of Chemistry, TU Dortmund University, Otto-Hahn Str. 6, Campus North, D-44227 Dortmund, Germany c Department of Pharmacology, Faculty of Veterinary Medicine, Cairo University, 12211 Giza, Egypt d Korea Food & Drug Administration, Food Chemical Residues Division, Osong Health Technology Administration Complex, 187 Osongsaengmyeong2(i)-ro, Osong-eup, Cheongwon-gun, Chungcheongbuk-do, Republic of Korea article info Article history: Received 13 July 2012 Received in revised form 29 November 2012 Accepted 11 December 2012 Available online 7 January 2013 Keywords: Beef muscles Carbamate Fenobucarb LC–MS/MS Residue analysis abstract This paper describes a comparison of the properties of the three versions of the QuEChERS method (quick, easy, cheap, effective, rugged and safe) – the original (unbuffered), acetate-buffered, and citrate-buffered methods – for the determination of fenobucarb residues in beef muscles via liquid chromatography–elec- trospray ionisation tandem mass spectrometry (LC–ESI + -MS/MS). The recovery results were good for all the versions; however, the acetate-buffered version gave higher and more consistent recoveries for fenobucarb than the other versions. Performance characteristics, such as linearity, accuracy, and precision were determined. Matrix-matched standard calibration was used for quantification, obtaining recoveries in the range of 83.7–93.4% with relative standard deviations of <5%, at two spiking levels: 10 and 40 lg/kg. The limits of detection (LOD) and quantification (LOQ) were estimated to be 1.5 and 5 lg/kg, respectively. Finally, the method was applied to the analysis of 15 market samples, and no residues were found over the limit of quantification. The method developed was found able to determine the analyte with satisfactory intensity and accuracy. Ó 2012 Elsevier Ltd. All rights reserved. 1. Introduction Pesticides have played a very important role in the development of human agriculture since their invention, and are still irreplaceable today. Although, pesticides and veterinary drugs have found their way into a wide variety of applications and have played a significant part in constantly boosting agricultural production and animal hus- bandry, the hazards they have brought along with them to food safety and human health have increasingly become a focus of world attention (Pang et al., 2006). Carbamate insecticides are widely used in gardening and agriculture due to their broad spectrum of activity, relatively short environmental persistence, and relatively low mam- malian toxicity (Nunes, SklaÂdal, Yamanaka, & BarceloÂ, 1998). One of the methyl carbamate pesticides is fenobucarb. Wang, Mu, Bai, Zhang, & Liu (2009) investigated the possible ways by which the pesticides and their residues are accumulated in the body of livestock as follows: (a) direct exposure: broad-spec- trum pesticides such as N-methyl carbamates (NMCs), are com- monly used by veterinarians (oral or injection) to prevent livestock from parasites; (b) contamination from the environment: most of the pesticides are normally disposed of in the soil and/or water, and some are volatilised in the atmosphere when they are applied to the farmland, grassland, and forest; (c) food chain trans- fer: the pesticides could be easily transferred and accumulated in the body of the livestock fed with crops that are potentially con- taminated by pesticide residues. Continuous human exposure may lead to teratogenicity, mutagenicity, reproductive toxicity, carcinogenicity, and neurotoxicity (Alavanja, Hoppin, & Kamel, 2004). Therefore, it could be necessary to develop efficient meth- ods to characterise the pesticide residues in animal products. The most widely used method for the analysis of carbamate pes- ticides in foods is the HPLC method using post-column hydrolysis and derivatization with fluorescence detection (Fillion, Sauve, & Sel- wyn, 2000; Horwitz, 2000). While the method normally gives better sensitivity, it is often time-consuming, including several steps in sample preparation. It has been stated that liquid chromatogra- phy/tandem mass spectrometry (LC–MS/MS) has been used for the quantification of carbamate insecticides and their environmental degradation products in non-biological samples (e.g. water, fruits, and vegetables) (Banerjee et al., 2007; Ito et al., 2008; Kanrar, Mandal, & Bhattacharyya, 2010; Sagratini, Manes, Giardina, Damiania, 0308-8146/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.foodchem.2012.12.029 ⇑ Corresponding authors. Tel.: +20 2 27548926; fax: +20 2 35725240 (A.M. Abd El-Aty), tel.: +82 62 530 2135; fax: +82 62 530 0219 (J.H. Shim). E-mail addresses: abdelaty44@hotmail.com (A.M. Abd El-Aty), jhshim@chonnam. ac.kr (J.-H. Shim). Food Chemistry 138 (2013) 2306–2311 Contents lists available at SciVerse ScienceDirect Food Chemistry journal homepage: www.elsevier.com/locate/foodchem