While {HEAD ~ the exclusion} of {TAIL ~ sodium} has received the most attention because of its ubiquitous presence and high mobility, the other alkali metal ions, especially potassium and lithium, are also desirably kept to acceptable levels 
of
While { HEAD ~ the exclusion } of { TAIL ~ sodium } has received the most attention because of its ubiquitous presence and high mobility , the other alkali metal ions , especially potassium and lithium , are also desirably kept to acceptable levels
OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH