PIXE analysis of Nigerian flour and bread samples

• The PIXE technique has been used to determine K and Br in a major Nigerian food item.
• Samples were analysed using two proton beam energies, namely 1.25 MeV and 2.15 MeV.
• Mismatched Ca results reflect its nature and accuracy/precision of the procedure.
• Explanations for the presence of the contaminant in the samples are presented.
• Other sources originating from erroneous burning of dangerous products suspected.

The alleged use of potassium bromate (KBrO3) in bread baking led a few authors to report on the chemical methods for the determination of KBrO3 levels in bread. In order to examine the potentials of a non chemical particle induced X-ray emission (PIXE) method for this purpose, six sets of samples, each composed of flour, dough and bread from a production batch were analysed. The samples were obtained from six different bakers of bread at Ile-Ife, Nigeria. The flour samples were air-dried while others were freeze dried at about −16 °C. The samples were homogenised in an agate mortar and then pelletised. Samples were analysed at the CTN standard PIXE setup and standard procedures for thick target samples analysis were followed. In some samples significant concentrations of bromine were found. In the present work we present possible explanations for the presence of this potentially dangerous contaminant in the samples.