Approaching a Universal Pneumatic Nebulizer
Jerry Dulude (USA), Vesna Dolic and Peter Liddell (Australia), Glass Expansion (www.geicp.com)
PE OPTIMA 2100DV ICP-OES
VARIAN VISTA MPX AXIAL ICP-OES
EXPERIMENTAL
111230 111314 111307 111219 111333
Mg 280.271
Mn 257.610
2
Mo 202.031
Ni 231.604
S 181.975
1
S 181.975
Si 251.611
0
Linear (Average60)
Serial number
Serial number nebulizers
Serial number
Figure 10: Effect of Pressure on
Performance- Detection Limit (2ml/min uptake)
Figure 8: Effect of Pressure on PerformanceShort-term Stability (0.4ml/min uptake)
4.00
30psi
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
3.50
60psi
Al 396.152
Cr 267.716
Cu 327.395
Mg 280.270
2
Mo 202.032
Avg.AR30
3
Detection Limit (0.4ml/min)
1.40
1.20
As 188.980
1
Ca 393.366
Cr 267.716
0.95
Cu 327.395
Mg 280.270
Mn 257.610
60psi
0.80
30psi
60psi
0.60
0.40
Mo 202.032
Ni 231.604
0.20
P 213.618
n
20
6.
20
0
.6
11
Z
S
i2
51
97
2
S
18
3.
1.
61
8
4
21
P
31
.6
0
27
0
N
i2
M
g
76
28
6.
0.
49
1
5
39
K
32
7.
71
C
u
26
7.
C
r
39
3.
36
6
6
03
C
a
5.
4
8.
45
B
a
Avg.AR30
18
Avg. AR60
98
0
.1
52
0.00
A
s
Serial number
Zn 206.200
96
11
16
86
11
17
80
11
16
54
11
17
77
11
16
53
0.8
A
l3
0.85
1.00
Normalized DL
Ba 455.403
11
12
30
11
13
14
11
13
07
11
12
19
11
13
33
Normalised emission counts
Al 396.152
0.9
Si 251.611
Zn 206.200
0.50
Avg30
Avg60
0.00
111333
111219
111780
111686
MFR IDL
111654
11
Figure 6: Effect of Pressure on Performance-
1.1
30psi
P 213.617
1.00
60psi
Serial number
Figure 3: Effect of Pressure on Performance
Signal Intensity (2ml/min uptake)
1.05
Ni 231.604
30psi
Serial number
16
5
7
11
17
7
4
11
16
5
0
17
8
6
Nebulizer Serial Number
11
11
16
8
3
11
13
3
9
11
12
1
7
13
0
11
11
11
111314
13
1
0
12
3
4
0
111219
Mo 202.031
1.50
Zn 206.200
Avg. AR60
111230
Mn 257.610
P 213.618
0.5
111307
Mg 280.271
Ni 231.604
Si 251.611
111333
Cu 327.393
2.00
Mn 257.610
1
0
Cr 267.716
l3
96
.1
53
B
a
23
3.
52
7
C
r2
67
.7
16
K
76
6.
49
M
0
n
25
7.
61
N
0
a
58
9.
59
2
P
21
3.
61
7
Zn
20
6.
20
0
60psi
2.5
RSD%
Ca 393.366
RSD%
3
Ca 317.933
2.50
Ba 455.403
A
30psi
250000
Figure 1: Sample Intro System
Ba 233.527
As 188.980
3.5
50000
As 188.979
3.00
4
300000
200000
Al 396.153
normalized DL
350000
150000
Zn 206.200
Avg.AR30
111686 111780 111654 111777 111653
Long-term Stability (2ml/min uptake)
2ml/min
0.4ml/min
11
16
53
Average30
11
16
86
11
16
54
Average60
11
17
80
11
17
77
19
11
12
33
13
11
13
11
86
16
77
11
17
80
11
17
P 213.617
Si 251.611
Zn 206.200
Avg. AR60
0.3
100000
SeaSpray
Concentric
Glass
Nebulizer
With EzyFit
And EzyLok
60psi
11
Zn 206.200
Cu 327.393
P 213.617
0.5
Si 251.611
0.5
Cr 267.716
3
Ni 231.604
0.7
0.6
P 213.618
30psi
Na 589.592
Ni 231.604
0.7
Ca 317.933
60psi
11
12
30
11
13
14
11
13
33
a
11
12
19
a
Mo 202.032
0.8
30
0.9
4
Mo 202.031
12
Mn 257.610
Mn 257.610
11
Mg 280.270
1.1
0.9
07
Cu 327.395
Mg 280.271
13
1.3
Ba 233.527
K 766.490
11
Cr 267.716
1
53
Ca 393.366
As 188.979
5
Cu 327.393
16
30psi
Ca 317.933
Cr 267.716
11
1.5
Ba 455.403
6
Ba 233.527
1.1
54
60psi
30psi
16
As 188.980
1.5
Tracey
Cyclonic
Spray
Chamber
With Helix
As 188.979
11
1.7
Normalised emission counts
Al 396.152
7
Al 396.153
1.2
1.9
Figure 5: Effect of Pressure on Performance-
Figure 2: Inter-Nebulizer Study
Results (60psi)
Counts
A Tracey™ Cyclonic spray chamber was used
with a SeaSpray™ concentric glass nebulizer
(both from Glass Expansion, Inc., Pocasset,
MA and shown below in Figure 1). Standard
conditions were used across the board on both
a Varian Vista MPX and a Perkin Elmer Optima
2100. Both ICP-OES instruments were used
with axial view for all lines.
1.3
RSD
Short-term Stability (2ml/min uptake)
To determine the effects of subtle changes in
parameters, it is necessary to first establish the
inter-nebulizer variability within a given design.
Figure 2 demonstrates the inter-nebulizer variability
for a group of 5 different 60 psi nebulizers of the
same configuration at two different uptake rates.
Note that even though the uptake rate has been
decreased by a factor of 5, emission intensity counts
are decreased by only about 20 to 25%. This is due
to the much higher efficiency produced at lower
uptake rates.
Figure 9: Effect of Pressure on PerformanceLong-term Stability (2ml/min uptake)
Figure 7: Effect of Pressure on Performance
Signal Intensity (2ml/min uptake)
11
13
07
Figure 4: Effect of Pressure on Performance-
Inter-Nebulizer Variation
RSD%
Glass Expansion currently designs nebulizers
to accommodate the recommended gas
pressures and flows of the various
spectrometer manufacturers. However, it is
desirable to design a single nebulizer that
when run under high pressure conditions will
generate a finer mist and more of it. In this
study a nebulizer was designed to operate at
60psi, markedly higher than that of a standard
nebulizer. This nebulizer was compared to the
standard for a variety of performance
parameters on two different ICP-OES systems.
14
INTRODUCTION
DISCUSSION
and
Figure 2 illustrates that the high reproducibility of various nebulizers of the
same design enables detection of differences between nebulizers
of a different design. Figures 3 through 6 show the improvements
provided by the 60psi design in terms of intensity, stability, and detection
limit for the Varian Vista MPX. This improvement is duplicated for the
same parameters on the Perkin Elmer 2100 (Figures 7 through 10).
Although all studies were conducted at both 0.4 and 2.0ml/min uptake
rates, a clear difference was not always revealed for both. Therefore, in
some cases, data is shown for one or the other. We are currently
Investigating further to determine the source of these anomalies.
CONCLUSIONS
A pneumatic nebulizer operated at 60psi
offers significant improvements in performance over the standard nebulizer for two
different ICP-OES manufacturers and
models. Future work will center on the
improvement in performance at lower
uptake rates and the ability of these
nebulizers to handle high dissolved solids
samples.
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