The determination of the flour improver potassium bromate in bread by gas chromatographic and ICP‐MS methods

The development and application of two methods for determining bromate in bread are described. A gas chromatographic (GC) method which relied on the formation of a volatile derivative of bromate gave a detection limit of 12 μg/kg. Duplicate analyses agreed well but recovery from breads spiked with bromate were low and averaged 30% for brown bread and 42% for white bread. Further studies indicated that this was caused by the derivatization reaction being suppressed by components of the sample and reagents used in their preparation. After taking both these factors into account, a recovery of 80% could be achieved. The GC method was used to carry out a survey of retail bread samples in 1989. Bromate was found in all six unwrapped breads analysed (median 35 jig/kg, range 17–317 μg/kg), whilst for 22 wrapped breads, seven were found to contain bromate (median < 12 μg/kg, range < 12–238 μg/kg). A second method of analysis employing inductively coupled plasma‐mass spectrometry (ICP‐MS) was developed which provid...