Full length articleA rapid monitoring method for inorganic arsenic in rice flour using reversed phase-high performance liquid chromatography-inductively coupled plasma mass spectrometry

- A new HPLC-ICP-MS method was developed for the rapid monitoring of inorganic As.
- Inorganic As can be analyzed directly since As(III) and As(V) co-eluted.
- Inorganic As can be separated from all organoarsenic compounds in rice.
- Three replicates can be analyzed within 6 min.
- Complete extraction of As species from rice flour was achieved within 15 min.

A new rapid monitoring method by means of high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) following the heat-assisted extraction was developed for measurement of total inorganic arsenic species in rice flour. As(III) and As(V) eluted at the same retention time and completely separated from organoarsenic species by an isocratic elution program on a reversed phase column. Therefore, neither ambiguous oxidation of arsenite to arsenate nor the integration of two peaks were necessary to determine directly the target analyte inorganic arsenic. Rapid injection allowed measuring 3 replicates within 6 min and this combined with a quantitative extraction of all arsenic species from rice flour by a 15 min HNO3-H2O2 extraction makes this the fastest laboratory based method for inorganic arsenic in rice flour.