Abstract
The levels of arsenic, cadmium, chromium, cobalt, copper, iron, lead, manganese, nickel, and zinc in some gluten-free food samples used for celiac disease patients have been determined after microwave digestion by inductively coupled plasma mass spectrometry (ICP-MS). The concentrations were found in the range of 0.09-0.66 (As), 2.9-6.6 (Cd), 4.7-100.3 (Cr), 866-2009 (Co), 0.043-0.26 (Cu), 3.2-17.4 (Fe), 1.4-10.5 (Pb), 12.9-41.3 (Mn), 0.35-0.46 (Ni) and 0.021-0.268 (Zn) mg kg(-1). The detection limits for As, Cd, Cr, Co, Cu, Fe, Pb, Mn, Ni, and Zn were 0.33, 0.009, 0.26, 0.041, 0.17, 1.36, 0.025, 0.061, 0.042, and 0.29 mg kg(-1), respectively. The accuracy of the method was confirmed by analysis of the standard reference material SRM 1568a Rice Flour. The results were compared with related works published for gluten-free foods used around the world and it was found that the Mn and Fe levels obtained in this study were at higher levels. The highest Ni, Co, Fe, and Cr levels were in Rice Flicks. The lowest Mn, Co, Zn, As, and Cd levels were in the Rice Thins samples.
A hierarchical cluster analysis of the results was performed to identify similarities between the food samples based on element component.