none 

Statements about this table:
the value of quantity be 2×10 - 6 at 2 ppm
10 - 12 be the coefficient of 2 ppt
coefficient
parts - per example
uno equiv
10 2
2%
2 centiuno
10 3
2 ‰
2 milliuno
10 6
2 ppm
2 microuno
10 9
2 ppb
2 nanouno
10 12
2 ppt
2 picouno
coefficient
symbol form
value of quantity
10 2
2 cu
210 2
10 3
2 mu
210 3
10 6
2 µu
210 6
10 9
2 nu
210 9
10 12
2 pu
210 12