ICP-MS: Purity of Water in Olin 330

Element	Mass	Olin sink DI water, ppb	Schenectady tap water, ppb
Li	7	0.002	3.1
B	11	0.000	25
Al	27	0.4	0.0
V	51	0.001	0.18
Cr	52	0.003	0.025
Fe	54	0.15	18
Mn	55	0.007	3.2
Co	59	0.001	0.10
Ni	60	0.006	11.5
Cu	65	0.130	533
Zn	66	0.71	124
As	75	0.028	0.58
Se	77	0.000	0.71
Rb	85	0.002	0.19
Sr	86	0.023	362
Mo	98	0.010	0.37
Cd	112	0.000	0.007
Sn	120	0.004	0.39
Sb	121	0.003	0.081
Cs	133	0.000	0.003
Ba	137	0.006	32
W	184	0.001	0.007
Tl	205	0.000	0.006
Pb	208	0.032	1.4
U	238	0.001	0.24

These values were derived by standards-based analysis not long after the lab was commissioned, probably around 2000. Blank water was from a 18.3 MΩ DI system in the ICP-MS hood. Remember that deionized water purification systems, like we have, change in their effectiveness over time. Most critical is the Olin house DI water system, which is the first line of defense for analytical water purity. The lab has a small conductivity meter, which should usually read <1 μSiemens at the sink DI taps if the system is doing its job.

Generally the tap DI water is pretty clean. Olin house water has Fe, Cu, Zn, and Pb. Schenectady tap water has everything, of course, but none are of any health concern at the concentrations analyzed here. Remember that natural waters, in contact with natural soil and rock, will have small amounts of almost every chemical element there is, from lithium to uranium. Schenectady tap water is not unusual. The analyses here say nothing about organic or biological contaminants, which we are unable to analyze in our lab.