abstract
The determination of inorganic arsenic species in food has become very important during the last few years,
since As(III) and As(V) are considered carcinogenic and found at high concentrations in food products, such
as rice. The present work describes the development of three different methods for the determination of total
arsenic, total inorganic arsenic, and As(III)–As(V) in rice and rice flour food products, purchased from the
local market by electrothermal atomic absorption spectrometry (ETAAS). The methods were based on the
use of different selective extraction procedures and the optimization of all crucial instrumental and methodological
parameters. By these new preparation procedures for the determination of arsenic species, the loss
and transformation of analytes during the extraction and digestion steps was prevented. For the validation
of each method, precision, accuracy, and selectivity have been assessed, as performance criteria. All developed
methods were accurate and precise. The calculated recoveries ranged between 92% and 105% and the
(%) relative standard deviation values, under repeatability or reproducibility conditions, were lower than
15% for all different concentration levels tested. The validated methods were applied successfully for the determination
of total arsenic and total inorganic arsenic in a proficiency test organized by the International
Measurement Evaluation Program (IMEP-107). The methods were also applied in rice and rice flour samples
purchased from the Greek market and the obtained results indicated that in almost all samples total arsenic
and total inorganic arsenic were detected at ng/g levels.
© 2012 Elsevier B.V. All rights reserved.