Separate quontitative determination of organic and non-organic arsenic in sea products

The performed research is truly vital, as As (arsenic) concentration in food products is now of great interest. The US ATSDR and EPA enlist As among the most toxic substances which are dangerous for human health. We suggest a procedure for separate quantitative mass fraction determination for organic (oAs) and non-organic (iAs) arsenic compounds in sea products with solid phase extraction (SPE) application combined with atomic adsorption spectrometry. Samples were prepared according to the following procedure: liquid extraction phase with simultaneous As (III) oxidation into As (IV) with hydrogen peroxide and As (V) extraction into a 0.055 M liquid phase with hydrochloric acid. Arsenic organic and non-organic compounds were separated via solid phase extraction with Strata SAX cartridges (Sorbent Lot Number: S208-0058). To quantitatively assess the obtained samples, we applied atomic-adsorption techniques for As determination with "KVANT-2A-GRG" spectrometer according to the State Standard 51766-2001. We revealed that common As concentration didn't conform to fixed standards in 8 out of 17 analyzed samples (2 shrimps, 1 crab, 1 fish, and 4 seaweeds). However, iAs concentration was significantly lower than oAs concentration in all the samples. 6 out of 17 analyzed samples didn't contain any iAs within detection limits (0.1 mg/kg), and apparently all the As concentration occurred due to its organic compounds. The suggested procedure for separate oAs and iAs detection is relatively simple in terms of devices applied in it, and quite cheap, as SPE cartridges needed to perform it can be re-used after re-conditioning. This procedure, after a proper metrological validation, can be implemented in most laboratories which are certified to examine chemical safety of food products.