Sample preparation and spectrometric methods for elemental analysis of milk and dairy products - A review

Because of the wordwide consumption as an important source of proteins and nutrients and frequent incidence of tampering, there is a high demand for quality control of milk and dairy products. A diversity of analytical methods has been proposed for sample pretreatment (analyte extraction and sample mineralization), as well as for elemental determination. This wide availability of analytical alternatives makes the selection of suitable procedures a challenging task for the analysts. This review shows a critical evaluation of this issue, covering from conventional alternatives to innovative proposals aiming at faster and more environmentally friendly approaches. The literature survey demonstraded the predominance of microwave-assisted acid digestion for sample mineralization and plasma-based techniques for determination of macro and micronutrients (ICP-OES) and toxic species (ICP-MS).