Determination of arsenic species in seafood samples using a combination of HPLC and ICP-MS after ultrasonic assisted sample preparation.

Abstract

In this study, an analytical method was applied for the separation and determination of inorganic and organic arsenic species (As⁺³, As⁺⁵, AsB, MMA) in anchovy, haddock, mussels and prawns using HPLC coupled with ICP-MS. Efficient separation of the arsenic species on the HPLC-ICP-MS system was achieved using 50 mM (NH₄)₂CO₃ at pH 9.50 diluted in 1 % methanol and 0.50 mM EDTA as mobile phase. The arsenic species were extracted from the samples by means of ultrasonically assisted sample preparation. The LOD/LOQ values of the detection system were 0.07/0.22 ng/mL, 0.12/0.41 ng/mL, 0.06/0.22 ng/mL and 0.03/0.11 ng/mL for arsenobetaine (AsB), As⁺³, methylarsonic acid (MMA) and As⁺⁵, respectively. The relative standard deviations calculated for the lowest calibration standards ranged between 1.01 and 7.88 %, verifying good precision for replicate measurements. The accuracy of the method was validated by spike recovery experiments, with recorded recoveries in the range of 85-117 %.The total arsenic content of the extracts was determined by direct ICP-MS analysis. A certificated reference material (NIST-1573A) was analyzed for the total As concentration. The method was successfully applied for the qualitative and quantitative determination of AsB, As⁺³, MMA and As⁺⁵ in the seafood samples ranging from 6.0 to 5700 ng/g. The carcinogenic and non-carcinogenic risk for haddock and anchovies was low, whereas the carcinogenic risk for prawns was relatively high but below the threshold value, according to the risk assessment of the samples.