Radial, Axial or Dual View ICP: Which Do You Choose? Manny Almeida Teledyne Leeman Labs, Inc. Hudson, NH 03031 Manuel.Almeida@Teledyne.com
Teledyne Leeman Labs, Inc. US based manufacturer of Elemental Analysis instruments Located in Hudson, NH Manufacturing elemental analyzers for 30 years Instruments Manufactured Hydra II and QuickTrace Series of Mercury Analyzers o Cold Vapor Atomic Absorption (CVAA) o Cold Vapor Atomic Fluorescence (CVAF) o Solid Mercury Analyzer (Hydra II C) Prodigy DC Arc o Elemental Analysis of Solid Samples Prodigy7 and Prodigy Series ICP-OES o Elemental Analysis of Liquid Samples
Teledyne Leeman Labs, Inc. Prodigy7 ICP Hydra and QuickTrace Mercury Analyzers Prodigy DC-Arc Prodigy ICP
Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) A multi-element technique that uses a high temperature plasma to excite atoms so they emit wavelength-specific photons of light, characteristic of each element. The number of photons produced is directly related to the concentration of that element in the sample ICPs consist of An Optical System RF Power Supply Sample Introduction System
Plasma Views Modern ICPs are available in three viewing configurations: Radial Axial Dual View Each view has advantages and disadvantages
Original ICP View Sometimes called Vertical or Side-On Plasma Accommodates all ICP matrices Detection Limits similar to Flame AA Better for Refractory Si, Ti, B, W, Mo Can analyze S, P and Halogens Radial ICP
Radial ICP Molecules (YO) Plasma Viewed Ions (Y + ) Atoms (Y)
Characteristics of Dedicated Radial Viewing Wide dynamic range Low to high concentrations Fewer dilutions compared to AA Excellent tolerance to dissolved solids 33% NaCl Excellent torch lifetimes Negligible Easily Ionized Element (EIE) effects Na affects K Radial detection limits
Sometimes called a Horizontal Plasma Useful analysis in many different sample matrices Excellent Detection Limits Has certain limitations Matrix Interferences Na and K can have problems The solution complicates sample preparation Axial ICP
Axial ICP Plasma Viewed Longer Path Length = Greater sensitivity
Why Axial ICP Works: Signal is proportional to the path length When viewing axially, the spectrometer observes only the central channel of the plasma (containing the analyte signal), blocking out the outer (high background) region This enhancement in signal-to-noise ratio provides 5-20x better improvement in detection limits. Signal measured here
Characteristics of Dedicated Axial Viewing ~10x better DLs than Radial Dynamic range shifts lower Less tolerant to dissolved solids than radial Torch lifetimes shorter than radial Torch longer than radial design Potential EIE effects
Dual View ICP Combines both Radial and Axial Views in one instrument Sensitivity of Axial ICP Better Detection Limits Sample Versatility of Radial ICP Freedom from matrix effects Provides Tremendous Comfort Factor The right view for any sample
Dual View
Dual View - Axial View Dual View Radial View Entrance to Instrument Plasma Source Mirror Mirror Torch
Dual View - Radial View Dual View Axial View Entrance to Instrument Plasma Source Mirror Mirror Torch
Dual View Radial length torch used
Characteristics of Dual View ~10x better DLs than radial Very wide dynamic range if using both views dynamic range shifts lower with axial view Tolerance to dissolved solids similar to that of dedicated axial Torch lifetimes shorter Torch longer than radial design Slots or hole to get radial view EIE effects of dedicated axial can be eliminated by using radial view of DV option Samples are only analyzed once Axial and radial view
Dynamic Range and Detection Limit
Which View Is Best for You? To decide which is the best fit for your application, the following questions need to be considered: What are your sample types? What are the concentration ranges in your samples? Do you need to determine any of the Alkali Elements?
Which View Is Best for You? What are your sample types? Aqueous Organic High Dissolved Solids Axial, Radial, Dual View Axial, Radial, Dual View Radial, Dual View
Which View Is Best for You? What are the concentration ranges in your samples? ppb ppm ppb- ppm ppm - % ppb - % Axial, Dual View Radial Axial, Dual View Radial Dual View
Which View Is Best for You? Do you need to determine any of the Alkali Elements? Li Na K Rb Cs No Axial, Radial Yes Radial, Dual View
Some Examples 25
Wear Metals in Oil What are your sample types? Organic What are the concentration ranges? ppm Alkali Elements? Yes Radial 26
Wear Metals in Oils typical results Measured Certificate % Recovery Ag 31.1 31.7 98.1 Al 12.2 11.8 103.4 B 107 102.4 104.5 Ba 1045 1037 100.8 Ca 2804 2832 99.0 Cd 12.7 12.3 103.3 Cr 4.0 3.7 108.1 Cu 22.6 22.6 100.0 Fe 122 119 102.6 K 20.5 20.4 100.5 Mg 500 490 102.0 Mn 8.6 8.2 104.9 Measured Certificate % Recovery Mo 32.4 31.9 101.6 Na 41.1 42.2 97.4 Ni 6.5 5.9 109.6 P 965.9 984 98.2 Pb 20.9 21.8 95.9 Sb 68 67.3 101.0 Si 43.5 45.1 96.5 Sn 8.9 8.9 99.7 Ti 7.4 7.1 104.2 V 42.8 42.5 100.7 Zn 1007 988 101.9 27
Soils (6010c) What are your sample types? Aqueous What are the concentration ranges? ppb - % Alkali Elements? Yes Dual View 28
NIST 2709 San Joaquin Element Concentration Found, mg/kg RSD Median Value, mg/kg Range, mg/kg As 16.5 1.5 <20 Ba 406 0.24 398 392-400 Cd 0.85 3.2 <1 Co 12.6 0.66 12 10.0-15.0 Cr 69.52 0.34 79 60-115 Cu 27.84 0.30 32 26-40 Mn 465.3 0.30 470 360-600 Ni 70.2 0.32 78 65-90 Pb 13.5 3.8 13 12.0-18.0 Sb 4.7 5.3 <10 Se ND - 0.014 V 52.7 0.34 62 51-70 Zn 95 0.41 100 87-120 Al 2.75 % 0.40 2.6 2.0-3.1 Ca 1.61 % 0.27 1.5 1.4-1.7 Fe 2.72 % 0.28 3 2.5-3.3 K 0.314 % 0.34 0.32 0.26-0.37 Mg 1.35 % 0.38 1.4 1.2-1.5 Na 0.076% 0.35 0.068 0.063-0.11
Wastewater (200.7) What are your sample types? Aqueous What are the concentration ranges? ppb - ppm Alkali Elements? Yes Dual View 30
Wastewater (200.7) NIST 1640a NIST 1640a Element Measured Conc (µg/l) Certified Conc (µg/l) %Rec Eleme nt Measured Conc (µg/l) Certified Conc (µg/l) %Rec Ag 7.88 8.081 97.5 Al 43.71 53 82.5 As 6.94 8.075 85.9 B 294.0 303.1 97.0 Ba 153.1 151.8 100.8 Be 2.89 3.026 95.4 Ca 5522.4 N/A --- Cd 3.76 3.992 94.2 Co 20.82 20.24 102.9 Cr 37.76 40.54 93.1 Cu 84.75 85.75 98.8 Fe 34.98 36.8 95.1 K 669.0 N/A --- Li 2.43 N/A --- Mg 991.3 N/A --- Mn 40.49 40.39 100.2 Mo 43.28 45.6 94.9 Na 3097.5 N/A --- Ni 26.41 25.32 104.3 P <MDL N/A --- Pb 10.23 12.101 84.6 Sb 4.57 5.105 89.5 Se 20.40 20.13 101.3 Si 4907.1 N/A --- Sn <MDL N/A --- Sr 113.3 126.03 89.9 Ti <MDL N/A --- Tl --- <MDL --- V 16.25 15.05 133.4 Zn 53.23 55.64 95.7
Wastewater (200.7) What are your sample types? Aqueous What are the concentration ranges? ppm Alkali Elements? Yes Radial 32
Wastewater (200.7) ELEMENT FOUND (µg/l) CERTIFIED (µg/l) ELEMENT Ag 102 106 Al 380 375 As 182 181 B 223 219 Ba 645 638 Be 191 194 Cd 112 113 Co 688 694 Cr 409 403 Cu 415 425 Fe 655 631 Mn 106 106 Mo 203 205 Ni 545 531 Pb 736 719 Sb 211 219 Se 192 188 Sr 724 713 Tl 96.2 95.6 V 153 156 Zn 551 544
Conclusion One view type doesn t fit all applications Look at advantages and disadvantage of each configuration Level of operator expertise To determine the one right for your application consider: Sample type Concentration ranges Elements determined