{HEAD ~ The extractor} comprises a microporous dialysis membrane tube filled with {TAIL ~ cation or anion exchange resin beads} 
{ HEAD ~ The extractor } comprises a microporous dialysis membrane tube filled with { TAIL ~ cation or anion exchange resin beads }
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL