Abstract: The speciation of arsenic in Lentinus edodes was analyzed using ultrasonic-assisted extraction (UAE) combined with high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS). Six arsenic compounds were extracted ultrasonically from the samples using 0.3 mol/L acetic acid solution as extraction solvent. The chromatographic separation was performed on a Hamiton PRP-X100 anion exchange column using a mixture of 25 mmol/L ammonium dihydrogen phosphate and water as the mobile phase. Under the optimized conditions, there were good linear relationships in the range of 0–50 μg/L for six arsenic compounds, with correlation coefficients all above 0.998 0. The limit of detection (LODs) of six arsenic species (AsC, AsB, DMA, MMA, AsIII, and AsV) were between 0.31 and 0.59 μg/L. The precision of the method, expressed as relative standard deviation (RSD), was less than 5%. The recoveries of AsC, AsB, AsIII, DMA, MMA, and AsV were in the range of 94.30%–102.75%. Speciation analysis could accurately determine six arsenic species in L. edodes. Inorganic arsenic was the main species in L. edodes, which was in the range of 48.68%–64.25%. This method was simple, rapid, sensitive and accurate, and could meet the requirements for the quantitative analysis of arsenic speciation in plant materials.

Key words: arsenic, speciation analysis, ultrasonic-assisted extraction, high performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS)