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ICP-MS SHORT COURSE TOPICS: 1. GENERAL ANALYTICAL CAPABILITIES 2. ICP AS ION SOURCE

ICP-MS SHORT COURSE TOPICS: 1. GENERAL ANALYTICAL CAPABILITIES 2. ICP AS ION SOURCE SAMPLE PREP & SAMPLE INTRO ION EXTRACTION, TRANSMISSION AND FOCUSING 5. MASS ANALYSIS – QUADRUPOLE, MAGNETIC SECTOR 6. ION DETECTION & VACUUM CONSIDERATIONS 7. MATRIX EFFECTS

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ICP-MS SHORT COURSE TOPICS: 1. GENERAL ANALYTICAL CAPABILITIES 2. ICP AS ION SOURCE

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  1. ICP-MS SHORT COURSE • TOPICS: • 1. GENERAL ANALYTICAL CAPABILITIES • 2. ICP AS ION SOURCE • SAMPLE PREP & SAMPLE INTRO • ION EXTRACTION, TRANSMISSION • AND FOCUSING • 5. MASS ANALYSIS – QUADRUPOLE, MAGNETIC SECTOR • 6. ION DETECTION & VACUUM CONSIDERATIONS • 7. MATRIX EFFECTS • SOLVENT REMOVAL & COLLISION CELLS QUESTIONS WELCOME ANYTIME!!!

  2. GENERAL ICP-MS REFS. HANDBOOK OF ICP-MS JARVIS, GRAY AND HOUK, 1992 VIRIDIAN PUBL., viridian.tc@virgin.net ICPs IN ANAL. ATOMIC SPECTROMETRY ICPMS MONTASER, ED., VCH, NEW YORK, 1992 & 1998 ICP MS HANDBOOK NELMS, ED. BLACKWELL/CRC, 2005 DEAN, PRACTICAL ICP SPECTROSCOPY, WILEY-VCH, 2005. HOUK, ACCOUNTS CHEM. RESEARCH,1994, 27, 333.

  3. ICP LISTSERVER Send e-mail message to Mike Cheatham at mmcheath@mailbox.syr.edu Include line: SUBSCRIBE PLASMACHEM-L@LISTSERV.SYR.EDU

  4. IONIZATION IN ICP M+/(M+ + M) (%) %M+2 T = 7500 K ne = 1 x 1015 cm-3 *These elements also make M+2

  5. ION SAMPLING INTERFACE ION LENS SAMPLER SKIMMER

  6. AGILENT 7500 LOAD COIL TORCH SAMPLER SPRAY CHAMBER SKIMMER

  7. ICP-MS DEVICE

  8. ANALYTE SPECTRA 10 ppb Ce 50X m/z = 136, 138 Ce+2 ~104 c/s ION SIGNAL CeOH+ Ce+ 106 c/s m/z = 140, 142 CeO+ ~104 c/s Mass to charge ratio

  9. ICP-MS CAPABILITIES DETECTION LIMITS 0.1 - 10 ppt routine 10 ppq SOME INSTS. USUALLY BLANK-LIMITED TOTAL SOLUTES 0.1% USUALLY OK 1% USUALLY PROBLEMS UNLESS USE FLOW INJECTION PRECISION 3% RSD ROUTINE 1% GOOD 1% ROUTINE W. INT. STDS. ACCURACY COMPARABLE TO PRECISION IF COMPENSATE FOR INTERFERENCES

  10. INTERFERENCES (REL. TO ICP-AES) SPECTRAL LESS FREQUENT OVERLAP LESS SEVERE MORE PREDICTABLE EASIER TO CORRECT MATRIX WORSE IN INTS. ICP-MS - PLUGGING - CHANGE OF SIGNAL (usually loss)

  11. SAMPLE DISSOLUTION DIGEST SOLID? HNO3 ONLY IF POSSIBLE HF, H2O2, HClO4 IF NECESSARY SAFETY!! APPROVED PROCEDURES MAKE UP IN AQUEOUS HNO3 TYP. 0.1% SOLUTE IN 1% ACID KEEP ACID CONC. CONSTANT TMAH (Me4N+OH-) IN H2O BIO. MATERIALS

  12. MICROWAVE SAMPLE DISSOLUTION SEALED VESSELS OK FOR VOLATILE ELEMENTS POWER REGULATED SAFETY VALVES

  13. HF HCl ACIDS NEEDED TO KEEP ELEMENTS IN SOLUTION

  14. LOW BLANKS? NALGENE OR POLYETHYLENE OK FOR DIW TEFLON CONTAINERS PREFERRED FOR ACIDIC SAMPLES ACID-WASH: 10% HNO3 + 5% H2O2 + 5% HF (CAREFUL!!) WARM OVERNIGHT OR LONGER RINSE & STORE IN DIW DUST-FREE ENVIRONMENT KEEP SAMPLE BOTTLES CAPPED

  15. Elemental Scientific Inc.MicroFlow PFA Nebulizer • 100% Teflon • Self-aspiration: • 20 µL/min • 50 µL/min • 100 µL/min • 400 µL/min

  16. Na 0 to 5 ppt CalibrationPFA-20 with HP4500

  17. S. JET & SKIMMING PROCESS ICP T ~ 5000 K N(v) Barrel shock VELOCITY v (Ar) N(v) Skimmer Collisions Directed flow in zone of silence - 0 + VELOCITY IN JET T ~ 150 K

  18. Sampler Skimmer Photo by A. L. Gray

  19. ION LENS Equipotential contours + + V1 V2 V1, V2 NOT DEP. ON m/z UNLESS: - IE = f (m/z) -SPATIAL DIST. = f (m/z)

  20. SIMION - EINZEL LENS 0 +110 0 volts FOCAL POSITION VARIES WITH APPLIED VOLTAGE INITIAL ION KE = 200 eV 0 +140 0 volts

  21. EINZEL LENS INITIAL KE =200 eV FOCAL POSITION VARIES WITH INITIAL ION KE 230 eV

  22. AGILENT 7500 OMEGA LENS

  23. Model of Ion Mirror Optics 28

  24. VARIAN ICP-MS

  25. QUADRUPOLE MASS ANALYZER y x U + V cos wt Thermo Elemental - (U + V cos wt)

  26. POTENTIAL = F (x,y,t) = (U + V cos w t)(x2 - y2)/r02 MATHIEU EQUATIONS a = 4zU/mw 2r02 q = 2zV/ mw 2r02 f = w t/2 + rods d2x/df 2 + (a + 2q cos 2f) x = 0 - rods d2y/df 2 - (a + 2q cos 2f) x = 0 d2z/ df 2 = 0

  27. FILTERING ACTION Positive Rods M + heavier ions M + lighter ions Negative Rods

  28. SIMION - QUADRUPOLE • Ions • All m/z = 100

  29. m/z = 100 STABLE 10 Ions All m/z = 90 10 Ions All m/z = 110

  30. STABILITY DIAGRAM UNSTABLE PATHS a = 4U/(m/z)r02w2 q = 2V/(m/z)r02w2 a q

  31. STABILITY DIAGRAM & SCAN LINE SCAN LINE U/V = const M M-1 a a = 4U/(m/z)r02w2 q = 2V/(m/z)r02w2 M+1 q

  32. PEAK SHAPE, RESOLUTION & ABUNDANCE SENSITIVITY RESOLUTION aU/V RATIO RES. & m/z CONTROLLED ELECTRONICALLY, NO MECH. MOVEMENT LOW RESOLUTION MEDIUM RES HIGH RES ION SIGNAL m/z M-1 M M+1 ABUNDANCE SENS. = (SIGNAL AT M) / (SIGNAL AT M-1 or M+1)

  33. ELECTRON MULTIPLIER ANALOG OUT, GATE GAIN ~ 106 -2800 V + -3000 V PULSE COUNTING OUTPUT GAIN ~ 108

  34. ALTERNATE MASS ANALYZERS MAGNETIC SECTOR Moens & Jakubowski, Anal. Chem. 1998, 70, 251A-256A. Douthitt, ICP Inform. Newsletter 1999, 25 (2), 87-120. Becker & Dietze, Spectrochim. Acta B 1998, 53, 1475-1506. Houk, Handbook of Elemental Speciation, R. Cornelis, Ed., Wiley, 2003.

  35. ESA ELEMENT SCANNING HIGH RES ICP-MS DEVICE Detector Entrance slit Quad lenses Extraction lenses Skimmer Sampler Magnet & flight tube ICP Neb & Spray chamber

  36. 10 ppb Zn PFA 100 64Zn+ 66Zn+ 68Zn+ 67Zn+ 70Zn+

  37. PEAK SHAPES LOW & HIGH RES. Spectra

  38. Photoresist Interferences on Cu 12C5H3+ 12CH332S16O+ 63Cu+

  39. MAGNETIC SECTOR MASS ANALYZER + ION MOVING THRU MAGNETIC FIELD STRENGTH B v B Fm v Fm Fm v Fm = MAGNETIC FORCE ALWAYS ACTS PERPENDICULAR TO DIR. OF MOTION

  40. MASS DISPERSION 320 280 240 200 7 ions start m/z = 200 Dm/z = 20

  41. BEAM BROADENING BY SPREAD OF KINETIC ENERGY 7 ions m/z = 200 KE = 2000 eV D KE = 10 eV

  42. FOCUSING EFFECT IONS INJECTED OVER VARIOUS ANGLES 7 ions m/z = 200 Dinjection angle = 1o

  43. FINNIGAN ELEMENT DEMO DOUBLE FOCUSING: SIMULTANEOUS ANGULAR & ENERGY FOCUSING

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