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Table 5 Data on surface area, generation of hydroxyl radicals and iron release

From: The iron-catalysed surface reactivity and health-pertinent physical characteristics of explosive volcanic ash from Mt. Etna, Italy

Sample # Surface area (m2/g)c Hydroxyl radical generation at 30 min (μmol/m2)c Iron release at 7d (μmol/m2)
10 min 30 min 60 min Fe2+ Fe3+ Total Fe
INGV_1 0.27 1.39 2.87 3.71 83.9 680.8 745.2
INGV_4 0.10 1.12 2.98 5.06 326.8 701.2 1028.0
INGV_5 0.13 1.35 3.08 7.02 77.8 583.3 661.1
INGV_8 0.08 1.68 3.52 6.75 226.9 1120.3 1347.2
ETNA4/11/02a 0.19b   4.72a 5.03a    502.5a
MON5/6/99a 1.28b   0.58a 0.58a    25.5a
CER30/11/95a 0.47b   2.03a 2.22a    238.3a
PIN4/7/91a 0.89b   1.88a 2.06a    29.9a
  1. aThese samples were used by Horwell et al. (2007) and have since been reanalysed on up to seven separate occasions, including for this study. The hydroxyl radical and iron release data presented here are the averages of these analyses. The original data in Horwell et al. (2007) for the Etna sample were 9.7 μmol/m2 for hydroxyl radical generation at 30 min and 655.1 μmol/m2 for total iron release at 7 days, and all data collected following that publication were less than these values
  2. bSurface area data from Horwell et al. (2007)
  3. cData are the average of three runs for the samples in this study