Content of iron, copper and zinc in white sugar samples from Polish and other European sugar factories

White sugar is a very pure food product, even though it contains very small, significant amounts of soluble and insoluble impurities. The content of these impurities has nutritional significance and determines the usefulness of sugar for various industrial applications. The aim was to evaluate the content of iron, copper and zinc in samples of white sugar from Polish factories compared with commercial white sugar samples from other European countries. The investigations were conducted on 72 campaign-averaged white sugar samples from 37 different Polish sugar factories from 1996 to 2000 and on 16 commercial white sugar samples from nine European countries. The content of iron, copper and zinc in those sugar samples was determined by means of FAAS both in the sediment and in the solution after filtration on 0.45-mum filters of sugar water solution. The content of iron, copper and zinc was low (averages 0.29, 0.06 and 0.07 mg kg(-1), respectively) in all the white sugar samples from Polish sugar factories and other European countries. Iron and copper found in all white sugar samples were mainly in insoluble form-77 and 69%, respectively. The contents of water-insoluble iron and water-soluble zinc in white sugar increase with a lowering of the quality of sugar evaluated according to the standards of the EU sugar market regime.