Journal of Chromatography B, 947–948 (2014) 49–56 Contents lists available at ScienceDirect Journal of Chromatography B j ourna l h om epage: www.elsevier.com/locate/chromb Application of C 18 -functional magnetic nanoparticles for extraction of aromatic amines from human urine Chunzhu Jiang, Ying Sun, Xi Yu, Yan Gao, Lei Zhang, Yuanpeng Wang, Hanqi Zhang, Daqian Song ∗ College of Chemistry, Jilin University, Qianjin Street 2699, Changchun 130012, PR China a r t i c l e i n f o Article history: Received 26 August 2012 Received in revised form 21 August 2013 Accepted 2 December 2013 Available online 17 December 2013 Keywords: Human urine Aromatic amines C18-functional ultrafine magnetic silica nanoparticles Magnetic solid-phase extraction Ultra fast liquid chromatography a b s t r a c t In this paper, a novel method using C 18 -functional ultrafine magnetic silica nanoparticles (C 18 -UMS NPs) as adsorbents was developed for rapid extraction and enrichment of aromatic amines from urine. C 18 - UMS NPs were prepared by chemical coprecipitation, silanization and alkylation. The aromatic amines can be adsorbed on C 18 -UMS NPs and isolated easily from the matrix with an external magnetic field. After desorption with acetonitrile, the aromatic amines were determined by ultra fast liquid chromatography. The experimental parameters, such as pH value of sample solution, amount of C 18 -UMS NPs, extraction time, type and volume of desorption solvent, and desorption time were optimized. The analytical per- formances of the present method were also evaluated. The limits of detection for 1-aminonaphthalene, 4-aminobiphenyl, 4,4 ′ -diaminodiphenylmethane and 4-aminophenylthioether were 1.3, 0.88, 1.1 and 1.1 ng mL -1 , respectively. The results showed that the present method was simple, highly efficient and rapid for the extraction and enrichment of aromatic amines from urine. © 2013 Elsevier B.V. All rights reserved. 1. Introduction There are various kinds of aromatic amines in the sur- rounding living environments, such as, aniline, benzidine, 4- aminophenylthiother, p-chloroaniline and so on [1,2]. They are toxic and carcinogenic. The concentration of aniline in drinking water is limited to 100 ng mL -1 [3]. Aromatic amines are widely used as raw materials or intermediates in the manufacturing of industrial chemicals such as pesticides, pharmaceuticals, explo- sives, rubber, epoxy polymers, cosmetics, dye stuff plants and aromatic polyurethanes [4–6]. The concentration of these amines in textile and leather articles is limited to 30 g g -1 by European Union regulations [7]. In some other countries, the acceptable limits were lower, e.g., 20 g g -1 in textiles [8]. The uses of carcinogenic aromatic amines have caused great harm to human health [9]. Car- cinogenic aromatic amines were detectable in several commercial hair dyes [10]. The known bladder carcinogen 4-aminobiphenyl (4- ABP) was detectable in several commercial hair dyes in levels up to 12.8 ng mL -1 [11]. The use of aromatic amines can increase the risk of cancer because they can be easily absorbed through the skin. These aromatic amines, such as 4-ABP, are important carcinogenic agents in tobacco smoke [12]. Environmental tobacco smoke should be a source of aromatic amines. When the azo dyes were absorbed ∗ Corresponding author. Tel.: +86 0431 85168399; fax: +86 0431 85112355. E-mail address: songdq@jlu.edu.cn (D. Song). by oral ingestion (particularly by babies sucking on toys and tex- tiles containing these dyes) and through sweat or via frication with clothing, the azo dyes can be degraded to release aromatic amines in liver cells, extrahepatic tissue and epidermal cells [7]. The carcino- genic aromatic amines in the body can harm human health. The determination of aromatic amines in human urine is particularly important. Wu et al. extracted and separated aromatic amines in lake water by solid phase microextraction (SPME) [13]. Dasgupta extracted aromatic amines by liquid-liquid extraction (LLE) [14]. However, the methods in these studies are time-consuming and organic sol- vent wasting. So it is necessary to develop a simple, rapid and reliable sample pretreatment method for the determination of aro- matic amines. Recently, magnetic nanoparticles (MNPs) have received increasing attention. Generally, MNPs are prepared by encap- sulating inorganic magnetic cores (mainly Fe 3 O 4 core) with organic polymer or inorganics [15,16]. Because of their large surface areas, unique physical and chemical properties, the MNPs have been widely used in many fields, such as biotechnology, biomedicine, protein separation, removal of metal ions and dyes [17–21]. The paramagnetic properties of these particles allow the easy isolation of products from solution by the external magnetic field. Thus, suspended MNPs tagged with analytes can be isolated from large volume samples using a magnet. The isolation and purification of the MNPs are easier and faster than those of other materials. In recent years, the MNPs were widely 1570-0232/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.jchromb.2013.12.008