ABSTRACT
Chemical contamination of milk can potentially occur from a number of sources, including application of agrochemicals (Whelan et al. 2011; Power et al. 2013), use of legal or illegal veterinary products (Le Breton et al. 2010), environmental pollution (Anon. 2011), natural toxins present in feed or forage (Hoogenboom et al. 2011; Baliukoniene et al. 2012), or from cleaning and disinfection of products used during milk production, processing and packaging (Schettler 2006). Extensive testing of milk is carried out by the dairy industry and regulatory agencies to protect public health. However, there are increasing reports of residues being detected in milk (Xin and Stone 2008; Anon. 2012; Fierens et al. 2012; Abernethy and Higgs 2013). This can be attributed to improvements in analytical instrumentation, which has supported the development of more sensitive detection methods that can analyse a wide range of residues in milk (Whelan et al. 2010; Abernethy and Higgs 2013). In addition, more sophisticated techniques are now being regularly applied, including high-resolution mass spectrometry, that can discover new emerging contaminants in foods that were previously unidentified (Stolker et al. 2008; Cordewener et al. 2009; Kim et al. 2009).
