Handling Interferences in the Modern Laboratory with Advanced Triple Quadrupole ICP-MS Technology

Transcription

1 Handling Interferences in the Modern Laboratory with Advanced Triple Quadrupole ICP-MS Technology Shona McSheehy Ducos The world leader in serving science

2 Elemental Analysis What are you trying to accomplish? Quantification of elemental impurities to validate purity of final product QA/QC to monitor quality, flag contaminated reagents, measure reaction efficiency/completeness 2

3 A Complete Elemental Analysis Portfolio Features include: Single- or multi-element analysis Measurement at concentrations from parts per trillion to percent Low-cost, high-throughput systems Space-saving ergonomic design with low gas consumption SF-ICP-MS Triple Quadrupole ICP-MS AAS ICP-OES Single Quadrupole ICP-MS Measure elemental impurities: Any sample matrix Any concentration OEA 3

4 Why Use an ICP-MS? Many elemental analysis techniques are suitable for measuring: Toxic metals (e.g. As, Cd, Hg, Pb) Impurities (e.g. S, Al, Ni) Essential elements (e.g. Fe, Se) Elemental species or nanoparticles ICP-MS is advantageous: Matrix tolerance robust interface and sample handling systems can significantly increase analysis times between operator intervention Interference removal advances in collision/reaction cell technology providing way to analyze more accurately at lower levels High sensitivity higher detection power enables lower limits of detection More than 9 orders dynamic range enables the analysis of both minors and majors in one analytical run Sensitive enough to determine high precision isotope ratios, speciation concentrations and particle numbers Are there any challenges? 4

5 Interferences Spectral Interferences ICP-MS 2 most common types: isobaric and polyatomic Isobaric Interferences Produced when isotopes from different elements have the same m/z ratio ( 58 Fe on 58 Ni, 204 Hg on 204 Pb) 64 Ni (1% abundant) 64 Zn (49% abundant) Isotopic pattern for Ni Isotopic pattern for Zn 5

6 Interferences Spectral Spectral Interferences ICP-MS 2 most common types: isobaric and polyatomic Polyatomic Interferences Produced when 2 or more isotopes combine to form a species with the same m/z as that of the analyte ion Ar, Air (O, N, C) ArAr, ArO, ArN, ArC, ArH, ArCa, ArNa, ArK, ArMg, ArCl, ClO, NO, CO, CaO, NaO, etc H 2 O, Ca, Na, K, Mg, Cl Products Reaction Reactants 6

7 Handling Interferences What Options are Available? Some typical interferences in ICP-MS: Mass Interferences Precursors 51 V 35 Cl 16 O, 37 Cl 14 N, 34 S 16 OH H, N, O, S, Cl 56 Fe Ar 16 O, Ca 16 O O, Ar, Ca 63 Cu Ar 23 Na, 12 C 16 O 35 Cl, 31 P 32 S 75 As Ar 35 Cl, Ca 35 Cl, Ar 34 SH, 37 Cl 2 H C, N, O, Na, P, S, Cl, Ar H, S, Cl, Ca, Ar Alternative sample introduction techniques E.g. aerosol desolvation to minimize the population of the precursor (parent) ions in the ICP ion source Cold Plasma: Reduce plasma power to reduce amount of Ar ionization Mathematical Correction Equations: Measure the isotope of interest, an un-interfered isotope, a polyatomic isotope and mathematically deconvolute to return an interference free value 7

8 Handling Interferences What Options are Available? Some typical interferences in ICP-MS: Mass Interferences Precursors 51 V 35 Cl 16 O, 37 Cl 14 N, 34 S 16 OH H, N, O, S, Cl 56 Fe Ar 16 O, Ca 16 O O, Ar, Ca 63 Cu Ar 23 Na, 12 C 16 O 35 Cl, 31 P 32 S 75 As Ar 35 Cl, Ca 35 Cl, Ar 34 SH, 37 Cl 2 H C, N, O, Na, P, S, Cl, Ar H, S, Cl, Ca, Ar Alternative sample introduction techniques E.g. aerosol desolvation to minimize the population of the precursor (parent) ions in the ICP ion source NOT A UNIVERSAL SOLUTION Cold Plasma: Reduce plasma power to reduce amount of Ar ionization NOT A UNIVERSAL SOLUTION Mathematical Correction Equations: Measure the isotope of interest, an un-interferred isotope, a polyatomic isotope and mathematically deconvolute to return an interference free value AMPLIFIES ERRORS, DOESN T ACCOUNT FOR UNKNOWN INTERFERENCES The ultimate solution: Thermo Scientific icap QCell Technology 8

9 Handling Interferences with Collision Reaction Cell Technology Interference Removal in SQ-ICP-MS Kinetic Energy Discrimination (KED) Target Analyte 75 As + Comprehensive interference removal is achieved Quadrupole set to filter out exact mass of target analyte Quadrupole isolates ions required for measurement QCell in collision mode with pure He uses energy discrimination ArCl +, Ca(OH) 2 H + He KED filters out unwanted polyatomic interferences, based on difference in crosssectional size of the analyte and polyatomic Complex Sample Matrix 9

10 Handling Interferences with Collision Reaction Cell Technology Interference Removal in SQ-ICP-MS and Low Mass Cut-Off Target Analyte 75 As + Comprehensive interference removal is achieved Quadrupole set to filter out exact mass of target analyte Quadrupole isolates ions required for measurement QCell in collision mode with pure He uses energy discrimination Ar +, Ca +, 35 Cl +, 16 O +, 1 H + Low mass cut off filters out unwanted precursor ions; ions are then unable to recombine later in the QCell and backgrounds are reduced further than He KED alone Complex Sample Matrix 10

11 Handling Interferences Low Mass Cut Off Eliminates lower mass ions that contribute to interferences from travelling through the QCell... Mass Interferences Precursors 51 V 35 Cl 16 O, 37 Cl 14 N, 34 S 16 OH H, N, O, S, Cl 56 Fe Ar 16 O, Ca 16 O O, Ar, Ca 63 Cu Ar 23 Na, 12 C 16 O 35 Cl, 31 P 32 S C, N, O, Na, P, S, Cl, Ar 75 As Ar 35 Cl, Ca 35 Cl, Ar 34 SH, 37 Cl 2 H H, S, Cl, Ca, Ar and reduces BECs even further than He KED alone 11

12 Handling Interferences Low Mass Cut Off Eliminates lower mass ions that contribute to interferences from travelling through the QCell... Mass Interferences Precursors 51 V 35 Cl 16 O, 37 Cl 14 N, 34 S 16 OH H, N, O, S, Cl 56 Fe Ar 16 O, Ca 16 O O, Ar, Ca 63 Cu Ar 23 Na, 12 C 16 O 35 Cl, 31 P 32 S C, N, O, Na, P, S, Cl, Ar 75 As Ar 35 Cl, Ca 35 Cl, Ar 34 SH, 37 Cl 2 H H, S, Cl, Ca, Ar and reduces BECs even further than He KED alone Universal interference removal for polyatomic interferences 12

13 There is No Application That Cannot be Tackled...Right? Trace elements in NaCl Elemental impurities in drug products Cr speciation in toys Air monitoring Pb in blood Trace elements in food Drinking water contaminants 13

14 An Application Challenge for a Single Quadrupole ICP-MS Measuring Se in a matrix containing high levels of Mo or Zr 80 Se 16 O+, 96 Zr+, 96 Mo+ Use oxygen reaction gas in the collision cell: Shift mass of Se away from Ar dimer Measure Se at the shifted mass Mass filter restrict to m/z = 96 Ar Ar + 80 Se + 80 Se 16 O + Problem: how to remove the matrix ions with m/z = 96 that do not react with oxygen? Introduce O 2 reaction gas Complex Sample Matrix Ar Ar +, 80 Se+, 96 Zr+, 96 Mo+ 14

15 The Interference Removal Power of a Triple Quadrupole ICP-MS Interference removal with an additional quadrupole: Filter all ions to allow passage of only ions with a mass-to-charge ratio of 80 Mass filter restrict to m/z = Se 16 O+ Ar Ar + Use reaction gas to shift the mass of the analyte ion Filter remaining ions to allow passage of ions with a mass-to-charge ratio of 96 Remove all interference effects from ions such as: Introduce O 2 reaction gas Ar Ar + 96 Zr + 96 Mo + 96 Ru Gd Dy ++ Mass filter restrict to m/z = 80 Complex Sample Matrix 96 Zr+, 96 Mo+ Ar Ar +, 80 Se+, 96 Zr+, 96 Mo+ 15

16 Thermo Scientific icap Qnova Series ICP-MS Thermo Scientific icap RQ ICP-MS (launched at Pittcon 2016) Simplicity, productivity and robustness for routine labs The icap RQ ICP-MS delivers the reliability, analytical performance and ease of use needed to meet the demands of the highest throughput labs. Thermo Scientific icap TQ ICP-MS (launched at WPC Feb 2017) Redefining triple quadrupole technology with unique ease of use The first, future proof triple quadrupole ICP-MS solution delivering enhanced performance and uncompromised ease of use for demanding routine analysis and challenging research applications. 16

17 Same Hardware Platform Familiar Look and Feel Innovative collision cell icap RQ ICP-MS Intuitive user-friendly software icap TQ ICP-MS Compact footprint Reaction Finder Software 4 mass flow controllers: He, O 2, H 2, NH 3 Additional quadrupole for superior interference removal Simplified power connections Quick connect and pushfit sample intro components Robust RF generator Built-in safety for handling reactive gases Bench-level easyaccess interface Analysis with SQ and TQ in a single sample run If you know how to use our single quadrupole, you already know how to use our triple quadrupole! 17

18 Thermo Scientific icap TQ ICP-MS How it Works Q3 set to product ion mass (m/z 91) Q2 filled with reactive gas (O 2 ) 91 [AsO] + 59 Co 16 O +, 150 Sm As + 91 [AsO] + 59 Co +, 91 Zr + Q3 isolates the product ion of the analyte and removes any remaining interferences through a second stage of mass filtration Optimal reaction conditions in Q2 are achieved through the selection of the appropriate measurement mode in Reaction Finder More specific interference removal through reactive chemistry inside the CRC Removal of unwanted ions in Q1 allows eliminates interferences on product ion mass and unwanted side reactions Result: - Better detection limits, even in challenging sample matrices Q1 set to analyte mass (m/z 75) 75 As + Q1 rejects unwanted ions and preselects the analyte. This first stage of mass filtration rejects precursors and ions with the same m/z ratio as the product ion. - Get more accuracy in unknown or varying sample matrices 18

19 The Power of Triple Quadrupole Technology Elemental impurities in Ni alloys Ti, Cr in high purity sulfuric acid As in Vitamin B12 (high Co matrix) Cd in the presence of high Mo concentrations As, Se in samples containing rare earth elements P, Ti in high Si matrix Ti in human serum As, Cr, V in high purity hydrochloric acid S, P in steel and high concentrations of iron Measure nanoparticles at ever decreasing diameters The possibilities are endless! 19

20 The Power of Triple Quadrupole Technology Problem: the possibilities are endless! Collision cell operation: Standard mode, collision (KED) mode, reaction mode, or a combination? If reaction mode, which reaction gas/es? Collision mode: what gas flow rate? Reaction mode: what gas flow rate/s? Collision cell voltage setting? Do you measure the analyte on mass or on massshift? Quadrupole 1: Voltage setting? Quadrupole 3: Voltage setting? Sample intro settings (RF power, plasma gases, spray chamber temperature) 20

21 Kick Interference to the Curb Analyte Gas M + Product ion Result Reaction Finder eliminate the complexity of triple quadrupole ICP-MS analysis 21

22 Eliminate the Complexity of Triple Quadrupole ICP-MS Reaction Finder for Thermo Scientific Qtegra Intelligent Scientific Data Solution Software Step 1: Select your element/s or isotope/s Step 2: You re done! Reaction Finder proposes the most appropriate gas/scan settings Settings for both single quad mode and triple quad mode are suggested, for reference Redefining triple quadrupole technology with unique ease of use 22

23 Simplest Method Development Using Reaction Finder Without Reaction Finder Select Select the Analytes to be measured Analyte Select For each analyte, select the isotopes to be measured With Reaction Finder Select Select the internal standard element Gas Select Select the Analytes to be measured Select Select Select the Q1 Analyte Select the CRC gas (None, He, H 2, O 2, NH 3 ) M + Product Ion Select Decide Select the internal standard element Are the suggested settings ok? If not, update them Select Select the mode (KED, Single Quad Mode, Triple Quad Mode) Analyze Enter sample names and positions or import from LIMS and start the LabBook Select Select the Q3 Mass (On-mass/mass shift product ion) Result Decide Analyze Are the suggested settings ok? If not, update them Enter sample names and positions or import from LIMS and start the LabBook Operator skills required Less than 20 Minutes until a method is set up and the samples are ready to run! 23

24 Application Examples The world leader in serving science

25 Analysis of Ti in Serum Background Joint replacements more frequently consist of metal-on-metal joints over ceramic or polymer Wear and tear on joints can release metal ions into the body accumulates in serum, blood and can pass into the urine Ti in these bodily fluids can indicate premature joint failure and infection Application challenge: Concentrations of Ti are extremely low (less than 1 ng ml -1 ) Main Ti isotope ( 48 Ti) has an isobaric interference from Ca, SO, PO Low concentrations (less than 1 ng ml -1 ) Isobaric interference of main isotope 48 Ti through 48 Ca 25

26 Analysis of Ti in Serum Analytical method needs to be: Robust to cope with sample matrix Sensitive to enable detection of low levels Specific to address Ti accurately despite interferences Analysis of Ti: Use Q1 to allow passage of only ions with m/z = 48 Use NH 3 to react with Ti and shift its mass to 114 Use Q3 to allow passage of only ions with m/z = 114 ICP-MS using triple quadrupole technology icap TQ ICP-MS 26

27 Results for Ti in Serum SQ mode produces false positive results unresolved isobaric 48 Ca interference! Only by using triple quad technology can accurate results for Ti be obtained! Background signal on 48 Ti 14 N 4 H 10 for a solution containing 10 mg L -1 of Cd Excellent agreement between measured and certified values Sensitivity achieved allowed trace concentrations of Ti to be measured in the prepared sample 27

28 Results All Other Elements Excellent agreement between measured and certified/reported values was achieved for all elements Full multi-elemental analysis together with dedicated interference removal for difficult analytes in one sample run Detection Limits as low as 20 ppq Elements accurately measured from ,806 ppb 28

29 Analysis of Se in Nickel Alloys Background Ni is used to produce a variety of alloys: stainless steels, copper-nickel alloys, nickel-chromium alloys Electronics, high temperature machine parts, hard-wearing coatings Presence of metal impurities (such as Se) can affect the properties of the material (corrosion resistance, high temperature strength, thermal expansion properties Application challenge: Se is challenging to ionize in a high Ni matrix (elevated 1 st ionization potential) Argon-based ions interfere with most abundant isotopes of Se Ni interferes with all isotopes of Se Additional interferences are generated in the presence of Br 29

30 Analysis of Se in Nickel Alloys Let s use O 2 and measure Se as SeO with a single quadrupole ICP-MS! Ion Mass 76 Se 77 Se 78 Se 80 Se 82 Se Shifted Mass 76 Se 16 O + (m/z = 92) 77 Se 16 O + (m/z = 93) 78 Se 16 O + (m/z = 94) 80 Se 16 O + (m/z = 96) 82 Se 16 O + (m/z = 98) Interferences 30

31 Analysis of Se in Nickel Alloys With the icap TQ ICP-MS, prevent precursor ions from entering into the collision cell, prior to reaction with O 2 Use Reaction Finder to automatically select the most appropriate mode, reaction gas and flow settings Analysis of Se: Use Q1 to allow passage of only ions with m/z = 80 Use O 2 to react with Se and shift its most abundant isotope to mass to m/z = 96 Use Q3 to allow passage of only ions with m/z = 96 Q3 set to product ion mass m/z 96 Q2 filled with reactive gas O 2 Q1 set to m/z [SeO] + 80 Se + 64 Ni16O +, 79 Br 1 H +, Ar Ar + 80 Se + 80 Se 16 O + H 2 O +, H 3 O +, Ni +, 96 Zr +, 96 Mo + 31

32 Summary A triple quadrupole instrument built on our original, innovative single quadrupole platform Triple quadrupole with smallest footprint on the market Easy-access sample introduction area Bench-level, pop-out interface Low maintenance and argon consumption requirements Intuitive set-up and operation Powerful interference removal for maximum sensitivity and accuracy Streamlined method development with Reaction Finder Automated, unattended analysis and intelligent dilution Common software with ICP-OES for reduced training and operator flexibility Find out more: thermofisher.com/icaptq The power of a triple quadrupole with the ease of use of a single quadrupole 32

33 Additional Resources analyteguru.com Educational Fun Engaging Keyword: Elemental Analysis 33

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35 Thank You Please join me in the Trace Elemental section of our booth where I ll address comments and questions. 35