The ability to rapidly detect {HEAD ~ a trace amount} of {TAIL ~ lead species} on site is very desirable 
of
The ability to rapidly detect { HEAD ~ a trace amount } of { TAIL ~ lead species } on site is very desirable
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH