ICP-MS

Separation and Identification of Organo-
Arsenic Species
pH 5.3
ICP-MS
ESI-MS
Intensityy
PPeak k11
Peak 2
Peak 3
ICP-MS m/z 75
m/z 167
m/z 139
m/z 277
m/z / 259 2 9
m/z 181
m/z 361
m/z 91
0 500
Retention time (s)
1000
Chromatograms (above) for ICP-MS ICP MS
measurement of As (mass 75) and ESI-
MS of various indicator masses. Mass
spectra (ESI-MS) for the 3 peaks show
characteristic fragmentation patterns
for the identified species – DMAE, DMA
and (maybe) DMAA
Hansen et al. J Anal At. Spectrom, 18, 474
Page Page 22 22
%
%
120
100
100 120
80
[M+H]
139.0
100
144.1 276.9
60
160.1 258 9
80
+
[2M+H] +
60
258.9
174.1 [2M-H2O] +
40
20
0
72
104
136
168
203.1
200
232
80
60
40
20
0
84
94.9 116.1
108
[M+H]
167.0
+
132
155.1
156
DMAE
Peak 1 (B)
191 191.1 1
213.1
229.0
173.1
180
204
m/z
DMA DMAA?
Peak 2 (C ) Peak 3 (D)
264
282.1
296
328
360
%
60
40
20
0
72
105
[M+H]
181.0
+
144.1
138
171
204
237
228
270
252
155.1
163.1
214.2 302.0
m/z m/z
276
300
[2M+H]
361.0
+
303
336
369
ESAC April 2008