{HEAD ~ The apparatus}, which may have a configuration similar to that of a felt tip marking pen, allows {TAIL ~ convenient use} of low volatility solvents in the catalyst solution 
allows
{ HEAD ~ The apparatus } , which may have a configuration similar to that of a felt tip marking pen , allows { TAIL ~ convenient use } of low volatility solvents in the catalyst solution
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH