The lipids（我的一个反应体系） were extracted twice with
ethyl acetate（乙酸乙酯）. The organic phase was back-extracted
with distilled water to remove residual acid. The ethyl
acetate extracts were evaporated to dryness under
nitrogen and redissolved in 1 ml ethanol.
back-extracted是反萃取吗？但我查的关于反萃取最后提取的物质都是在水中啊，但其我觉的这个文献说的应该还是在有机相（乙酸乙酯）中啊！想确认一下，请大家帮忙

The organic phase was back-extracted
with distilled water to remove residual acid.

这句话是说： 有机层用蒸馏水萃取除去其中的酸。就是用水洗的意思。