Temperature-Related Stability in Plasma Spectrometry

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Temperature-Related Stability in Plasma
Spectrometry

• Jerry Dulude, Ron Stux, and Vesna Dolic, Glass
  Expansion, jdulude_at_geicp.com

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Causes of Signal Drift in ICP-OES
Cause
Solution

• Optical drift
• RF instability
• Sample related baseline shift
• Matrix variations
• Drift in sample intro temperature

• Profiling thermostat
• Feedback loop
• Background correction
• Internal std. or matrix matching
• ????????

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IsoMist Programmable Temperature Spray Chamber
(PTSC)
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IsoMist Characteristics

• Programmable from -10 to 60C in 1 degree
  increments
• Maintains temperature to within 0.1 degree
• Built-in Peltier device
• No external plumbing
• Temperature measured near the chamber surface

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IsoMist on Optima 2100DV
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PE 2100DV Standard Parameters

• Power 1450 watts
• Coolant gas 15LPM
• Aux. gas 0.2LPM
• Quartz injector, 1.8mm bore
• Neb. Gas 0.7LPM
• SeaSpray concentric glass nebulizer (1ml/min)
• IsoMist Programmable Temperature spray chamber
  with Twister Baffled Cyclonic

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Intensity vs. Temperature-PE 2100DV(1ml/min
uptake)
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Temperature Plots on PE 2100DV
31 increase from 10 to 25C or 2 per degree C
31 increase from 25 to 35C or 3 per degree C
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Temperature Plots on PE 2100DV
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Temperature Plots on PE 2100DV
Avg. suppression of all lines
Interference std 1000ppm Na K, 500ppm Ca
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Temperature Plots on PE 2100DV
Avg. suppression of all lines
Avg. suppression of ion lines
Interference std 1000ppm Na K, 500ppm Ca
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IsoMist on the Varian Vista MPX
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Varian Vista MPX Standard Parameters

• Power 1300 watts
• Coolant gas 15LPM
• Aux. gas 1.5LPM
• Quartz injector, 2.3mm bore
• Neb. Gas 0.8LPM
• SeaSpray concentric glass nebulizer (0.4ml/min)
• IsoMist Programmable Temperature spray chamber
  with Twister Baffled Cyclonic

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Effect of Spray Chamber Temperature on Intensity
(Varian Vista MPX)
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Effect of Temperature on IntensityVarian Vista
MPX
10 increase from 20 to 25C or 2/degree C
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Effect of Spray Chamber Temperature Varian
Vista MPX
Transport Efficiency
Avg. Intensity
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Varian Vista MPX Parameters

• Power 1300 watts
• Coolant gas 15LPM
• Aux. gas 1.5LPM
• Quartz injector, 1.8mm bore
• Neb. Gas 0.8LPM
• SeaSpray concentric glass nebulizer (0.4ml/min)
• IsoMist Programmable Temperature spray chamber
  with Twister Baffled Cyclonic

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Temperature vs. Intensity (Varian Vista MPX-
1.8mm bore)
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Temperature vs. Intensity (Varian Vista MPX)
1.8mm bore
2.3mm bore
10 decrease from 20 to 40C or 0.5 per degree C
29 increase from 10 to 40C or 1 per degree C
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Low Sample Uptake Applications

• Biological applications
• Intracellular fluids
• Neonatal samples
• Forensic applications
• Speciation (HPLC-ICP-MS)
• Radioactive wastes reduction
• Low DLs desirable

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Effect of Temperature on Normalized Intensity (20
uL/min uptake rate)
PE Optima 2100DV
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Effect of Temperature on Intensity20ul/min
uptake rate
Avg. Intensity
Estimated Transport Efficiency
133 increase from 21 to 40C or 7 per degree C
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Spray Chamber Temperature Impact

• High impact with respect to intensity
• Interdependent with other plasma parameters
• Provides another dimension for optimization
• Must remain constant during the experiment

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Constant temperature benefits(1ml/min sample
uptake)

• Higher accuracy
• Higher productivity
• Greater reproducibility
• Better experiments