Formulation of Rapid Method for Detection and Estimation of Bromate in Serum and Confectionaries Consumed in Enugu, Nigeria

A bromate is a chemical compound (a salt or ester) containing the reactive group BrO3. Bromate anion, (BrO3 - ) is a bromine –base oxo-anion. Examples of bromates include sodium bromate, and potassium bromate. Both sodium bromate or potassium bromate are white crystalline substances that are readily soluble in water. Chemical properties of the sodium salt of bromate shows that it has a molecule of NaBrO3, molecular weight of 150.90g. Physical properties showed a state and appearance of odourless , white crystals with melting point of 38o c. It is slightly in organic solvent like alcohol but highly soluble in water. For potassium bromate, its molecular formula is KBrO3 , while molecular weight is 167.01g. It is slightly soluble in alcohol and insoluble in ether. Sodium bromate is produced by the introduction of bromide into a solution of sodium carbonate. The use of potassium bromate in flour milling and baking was banned in Nigeria by National Agency for food, drug sand control (NAFDAC) in 2003, and its use infringes on the drug and related products registration decree 20 of 1990 and NAFDAC Decree 15 of 1993. There are several existing methods for the determination of bromate , all with their different complexities , colourimeteric method, spectrophometric method, capillary electrophoresis, mass spectrometry flow injection analysis, whichever method that is used, the complex matrix in samples of bakery products dictate that a degree of sample pre-treatment is required. Secondly no conventional spot method for spot checks at retail outlets has been developed. The aim of this study is to formulate rapid method for detection and estimation of bromate in serum and confectionaries consumed in Enugu, Nigeria. All bread samples tested positive by the quantitative method, showing the presence of black spots. The black spot did not fade even after 24 hours. The filtrate of the same bread samples when applied on whatman No 1filter paper before dropping the potassium iodide reagent gave no black spot. Similarly, when the reagent dropped directly negative results negative results were obtained. The same samples were also tested using flooding method, described in the promethazine hydrochloride method and similar results were obtained. However, the colour for promethazine hydrochloride method was pink. The potassium iodide reagent gave consistently positive results throughout its storage period of three (3) months when applied directly on the loaf of bread. The methylene blue reagent developed for quantitative test was also tested using the quantitative procedure. The result showed the disappearance of the blue colour to the background colouralamost similar to that of the bread sample. The analytical performance was measured by determining eight (8) out of ten (10) of the positive sample were reported positive while four (4) out of five (5) negative samples were reported negative. This implies a false negative of two (2) and false positive of one (1). Apart from the interference of extraneous factors, whose presence did not interfere with the positivity and sensitivity of the spot and semiquantitative, the quantitative procedure may be applied in bromate estimation in bread with caution.

Keywords: Bromate, Estimation, confectionaries, formulation.