Inductively coupled plasma mass spectrometry (ICPMS) What is ICP MS - PowerPoint PPT Presentation

Basic and Application Inductively coupled plasma mass spectrometry (ICPMS)

What is ICP MS Inductively coupled plasma mass spectrometry (ICP-MS) is a type of mass spectrometry which is capable of detecting metals and several non-metals at concentrations as low as one part in 10 12 (ppt). This is achieved by ionizing the sample with inductively coupled plasma and then using a mass spectrometer to separate and quantify those ions. Mission : Convert all analyses species in sample to each isotope ions which be able to measure by mass spectrometer. Examples : if we are looking for Calcium in water sample. (CaCl 2 )• xH 2 O Ca + (CaCO 3 )• xH 2 O (CaSO 4 )• xH 2 O (CaF 2 )• xH 2 O 2

ICP-MS M ++ 2 nd ionization Ions M +  M +* Emission line 2 MS need an singly charged ions h  1 st ionization Atom M*  M . + h  M Emission HCL  atomization AAs Gas MX vaporization Solid (MX) n Solution droplet desolvation M(H2O) m + , X - 3

ICP-MS Instrumental Mass Ion Source Detector Analyzer Torch <1x10 -5 torr Spray chamber Nebulizer Ion source + + = Atmospheric pressure 4

ICP-MS Instrumental Mass Ion Source Detector Analyzer How to extract the ions into MS ? The positively charged ions that are produced in the <1x10 -5 torr plasma are extracted into the vacuum system, via a pair of interface “cones” and the “extraction lens” Sample cone Extraction lens Skimmer cone Interface Vacuum region Interface region Atmospheric pressure 5

ICP-MS Instrumental Mass Ion Source Detector Analyzer The Right Angular Positive Ion Deflection (RAPID) lens <1x10 -5 torr • The open lens stack eliminates lens cleaning maintenance and a completely off-axis design together with QCell technology delivers a class leading background noise. Ion, Neutral, Photons Elimination of neutral species Neutral, Photons Atmospheric pressure 6

Polyatomic interference 40 Ar 16 O 40 Ca 16 O 40 Ar 35 Cl 7

How to remove Polyatomic Interference? He KED mode Mass Ion Source Detector Analyzer Qcell Collision/Reaction Cell (CRC) • Flatapole technology for improved transmission <1x10 -5 torr • Low mass cut off filters out unwanted precursor ions • Single mode interference removal with He • He KED filters out unwanted polyatomic interferences • Small CRC volume for fast gas exchange • Flexibility to work with reactive gases, such as mixtures of O 2 7% dilute H 2 or 1% NH 3 • Non-consumable, zero-maintenance Atmospheric pressure 8

How to remove Polyatomic Interference? He KED mode Target Comprehensive He KED filters out unwanted polyatomic analyte Interference interferences 75 As + Quadrupole set to Removal filter out exact mass of target analyte High transmission enables analysis of even low e.g. 75As+ mass analytes in He KED mode Quadrupole isolates ions Single measurement mode for all analytes in wanted for analytical method measurement ArCl + Ca(OH) 2 H + He KED filters out No gas switching makes method more productive unwanted polyatomic and simple interferences, based on difference in cross-sectional size of the analyte and No change of measurement mode effectively polyatomic eliminates method development Complex matrix Unique Flatapole Design 75 As+ 40Ar35Cl + Ca(OH) 2 H + 9

How to remove polyatomic interference? He KED mode Collisional retardation / energy filtering Quadrupole Pre-Cell Cell From plasma To detector Decreasing Energy Collision/Reaction gas atom or molecule Analyte Ion M + - Small collision cross- section Energy Barrier Polyatomic Species e.g. ArX + – Larger collision cross-section Simple, effective interference removal 10

Simplicity and Productivity – Low mass cut-off Target Comprehensive QCell flatapole dynamically applies Low Mass Cut Off analyte Interference (LCMO) relative to target analyte 75 As + Removal Quadrupole set to filter out exact mass of target analyte Anal LMCO Interferences Precursors e.g. 75As+ Quadrupole 51 V 35 Cl 16 O, 37 Cl 14 N, 35 H, N, O, S, isolates ions 34 S 16 OH Cl wanted for measurement 56 Fe 39 40 Ar 16 O, 40 Ca 16 O O, Ar, Ca 63 Cu 45 40 Ar 23 Na, 12 C 16 O 35 Cl, C, N, O, Na, 31 P 32 S P, S, Cl, Ar 75 As 47 40 Ar 35 Cl, 40 Ca 35 Cl, H, S, Cl, Ca, Low mass cut off filters out unwanted precursor ions; ions 40 Ar 34 SH, 37 Cl 2 H Ar are then unable to recombine later in the QCell and backgrounds are reduced further than KED alone Comple x matrix Unique Flatapole Design 11

Simplicity and Productivity – Low mass cut-off Target Comprehensive QCell flatapole dynamically applies Low Mass Cut Off analyte Interference (LCMO) relative to target analyte 75 As + Removal Quadrupole set to filter out exact mass of target analyte Anal LMCO Interferences Precursors e.g. 75As+ Quadrupole 51 V 35 Cl 16 O, 37 Cl 14 N, 35 H, N, O, S, isolates ions 34 S 16 OH Cl wanted for measurement 56 Fe 39 40 Ar 16 O, 40 Ca 16 O O, Ar, Ca 63 Cu 45 40 Ar 23 Na, 12 C 16 O 35 Cl, C, N, O, Na, 40 Ar + , 40 Ca + , 31 P 32 S P, S, Cl, Ar 35 Cl + , 16 O + , 1 H + 75 As 47 40 Ar 35 Cl, 40 Ca 35 Cl, H, S, Cl, Ca, Low mass cut off filters out unwanted precursor ions; ions 40 Ar 34 SH, 37 Cl 2 H Ar are then unable to recombine later in the QCell and All unwanted precursors that contribute to backgrounds are reduced further than KED alone intereferences are eliminated Comple x matrix Unique Flatapole Design 12

Superior Interference Suppression Calibration curve for 75 As in a solution containing 0.5% HCl STD mode: Polyatomic interference leads to poor IDL KED mode: Polyatomic interference removed and elevated BEC IDL below 5 ppt 13

14 7 Li ~11,000 cps 7 Li ~1,000 cps 7 Li ~50 cps 35 Cl 16 O ~1,300,000 cps 35 Cl 16 O ~110,000 cps 35 Cl 16 O ~100 cps STD (no gas), KED and CCT mode 59 Co ~120,000 cps 59 Co ~65,000 cps 59 Co ~25,000 cps 115 In ~260,000 cps 115 In ~230,000 cps 115 In ~30,000 cps 140 Ce ~260,000 cps 140 Ce ~260,000 cps 140 Ce ~90,000 cps 238 U ~370,000 cps 238 U ~690,000 cps 238 U ~270,000 cps

What’s the difference between a SQ and TQ -ICP-MS iCAP RQ ICP-MS iCAP TQ ICP-MS Additional Q1 mass filter quadrupole Additional electronics Additional gases Enhanced software Same platform – there are more differences than you think! 15

Thermo Scientific TQ ICP-MS – How it Works 91 [AsO] + 59 Co 16 O + , 150 Sm ++ Q3 isolates the product ion of the analyte Q3 set to product ion mass and removes any remaining interferences ( m/z 91) through a second stage of mass filtration 75 As +  91 [AsO] + Optimal reaction conditions in Q2 are Q2 filled with reactive achieved through the selection of the appropriate measurement mode in Reaction gas (O 2 ) Finder Q1 rejects unwanted ions and preselects 59 Co + , 91 Zr + the analyte . This first stage of mass filtration Q1 set to analyte mass rejects precursors and ions with the same ( m/z 75) m/z ratio as the product ion. 75 As + 16

Find out what is going on inside the TQ ICP-MS 17

Thermo Scientific iCAP TQ ICP-MS Problem Feature Benefit Value TQ technology Meet requirements of Interference removal still Measure more accurately dramatically improves challenging applications major challenge in ICP- and with lower LOD interference removal MS Analyte Interference Interference M + M + (M+16) + Analyte with Interference Mass Shift 18

Interference removal using TQ Reaction Chemistry (with O 2 ) Precursor Ion Isobaric Interference Analyte Mass Shift Interference (M – 16) + M + (M + 16) + Mixture of analytes and interferences 19

Interference removal using TQ Reaction Chemistry (with O 2 ) Precursor Ion Isobaric Interference Analyte Mass Shift Interference Q1 (M – 16) + M + (M + 16) + (M – 16) + M + (M + 16) + Mixture of analytes and Filters Pre-Cursor Ions and interferences Mass Shift Interference 20

Interference removal using TQ Reaction Chemistry (with O 2 ) Precursor Ion Isobaric Interference Interference free Analyte Mass Shift Interference CRC TQ-O 2 Q1 Mass Shift (M – 16) + M + (M + 16) + (M – 16) + M + (M + 16) + (M – 16) + M + (M + 16) + Mixture of analytes and Filters Pre-Cursor Ions and interferences Mass Shift Interference 21

Interference removal using TQ Reaction Chemistry (with O 2 ) Precursor Ion Isobaric Interference Interference free Analyte Mass Shift Interference CRC TQ-O 2 TQ Mass Shift mode is typically used with: Q1 Mass Shift (M – 16) + M + (M + 16) + Oxygen, Ammonia, Hydrogen It is used for analytes which preferentially react with the reactive gas (M – 16) + M + (M + 16) + (M – 16) + M + (M + 16) + Mixture of analytes and Filters Pre-Cursor Ions and interferences Mass Shift Interference 22

Interference removal using TQ Reaction Chemistry (with O 2 ) Precursor Ion Isobaric Interference Analyte Mass Shift Interference Q1 Interference free (M – 16) + M + (M + 16) + (M – 16) + M + (M + 16) + Mixture of analytes and Filters Pre-Cursor Ions and interferences Mass Shift Interference (M – 16) + M + (M + 16) + CRC TQ-O 2 On Mass 23