ICP-MS analyses of different waters in Olin 330. Element concentrations are in parts per billion by weight.
Element Mass Blank signal, cps Standard concentration Big Barnstead DI system Olin house DI water Schenectady tap water
Li 7 27 10 0.003 0.002 3.1
B 11 164 10 0.010 0.000 25
Al 27 2790 100 0.2 0.4 0.0
V 51 4 10 0.001 0.001 0.18
Cr 52 80 2 0.002 0.003 0.025
Fe 54 87 500 0.10 0.15 18
Mn 55 419 100 0.007 0.007 3.2
Co 59 28 2 0.000 0.001 0.10
Ni 60 7 5 0.004 0.006 11.5
Cu 65 38 50 0.027 0.130 533
Zn 66 337 50 0.35 0.71 124
As 75 83 10 0.000 0.028 0.58
Se 77 105 10 0.113 0.000 0.71
Rb 85 11 10 0.003 0.002 0.19
Sr 86 150 500 0.009 0.023 362
Mo 98 3 5 0.014 0.010 0.37
Cd 112 6 1 0.000 0.000 0.007
Sn 120 77 1 0.001 0.004 0.39
Sb 121 12 1 0.002 0.003 0.081
Cs 133 9 1 0.000 0.000 0.003
Ba 137 940 100 0.000 0.006 32
W 184 4 1 0.001 0.001 0.007
Tl 205 11 1 0.000 0.000 0.006
Pb 208 31 50 0.013 0.032 1.4
U 238 4 10 0.001 0.001 0.24

 

Generally the DI waters are very clean. The only clear presence of contamination in the big Barnstead DI system is Fe, Pb, and Zn. Olin house water clearly has Fe, Cu, Zn, and Pb. Schenectady tap water has everything, of course, but nothing in concentrations that are of any health concern. Remember that natural waters, in contact with even untouched soil and rock, will have small amounts of every chemical element. For the elements shown, Schenectady tap water is not unusual for uncontaminated natural waters generally. The analyses here say nothing, of course, of organic contaminants, which we are unable to analyze in our lab.

 

I expect the deionized water available in the hoods to be even clearer than the Barnstead deionized water. Note that it is likely that element concentrations will vary over time.

 

Kurt Hollocher

Geology Department

Union College

Schenectady, NY  12308

U.S.A.