Extraction ability of Sn~(4+) and Sn~(2+) by TBP is compared experimentally, and Sn~(4+) appears a little better ability than Sn~(2+).

• 实验比较了TBP萃取Sn~(4+)与Sn~(2+)的性能,解释了Sn~(4+)比Sn~(2+)略易萃取的原因。