Profiles of concentrations of arsenic species in BM plasma collected during the remission induction therapy. BM aspirates were collected before the treatment start (day -1), and 14, 28, 42, and 56 days after the start of administration. The concentrations of arsenic species in plasma were determined with HPLC/ICP-MS as described in "Patient and Methods." Similar to Figure 3 (A), identification of arsenic species by a spike test was conducted using a plasma sample collected on day 14 and was shown in Figure 4 (A). The concentrations of arsenic species calculated from these chromatograms are shown in Figure 4 (B). (●): As(V); (■): As(III); (▲): MA(V); (♦): DMA(V); (O): AB.