Table 2. Extraction of Arsenic from Hijiki CRM 7405-a (Initial Arsenic Content = 35.6 ± 0.9 μg As g–1) by Various Extraction Solutionsa.
| solvent | total As [μg As g–1] | % of total As | relative polarity of pure solvents23 |
|---|---|---|---|
| hexane (pure solvent) | 0.97 ± 0.21 | 2.7 ± 0.6 | 0.009 |
| toluene | 6.58 ± 0.19 | 18.5 ± 0.5 | 0.099 |
| ethyl ether | 4.22 ± 0.05 | 11.9 ± 0.2 | 0.117 |
| MTBE | 4.50 ± 0.12 | 12.6 ± 0.4 | 0.124 |
| ethyl acetate | 4.72 ± 0.18 | 13.3 ± 0.5 | 0.228 |
| chloroform | 6.21 ± 0.31 | 17.4 ± 0.9 | 0.259 |
| DCM | 6.24 ± 0.05 | 17.5 ± 0.2 | 0.309 |
| acetone | 4.42 ± 0.14 | 12.4 ± 0.4 | 0.355 |
| acetonitrile | 3.74 ± 0.11 | 10.5 ± 0.3 | 0.460 |
a
Except for hexane, which was used alone, extraction solution was a mixture of solvent/MeOH (2 + 1, v/v). In all cases, 5 mL of solvent was used with 100 mg of CRM Hijiki (n = 3).