Back at the lab, he directs students in using the atomic absorption machine, an instrument that determines the amount of metal ions present in water in parts per million.
(he; directs; students; in using the atomic absorption machine; L:Back at the lab) (students; in using; the atomic absorption machine) (an instrument; determines; the amount of metal ions present in water in parts per million)
he students an instrument
directs in using determines
students in using the atomic absorption machine L:Back at the lab
the atomic absorption machine
the amount of metal ions present in water in parts per million