플라스마원소분석 ICP-AES, ICP-MS, HR-ICP-MS 서울대학교자연과학대학지구환경과학부 허영숙
플라스마원소분석 ICP-AES 10,000원 / 시료 Q-ICP-MS 20,000원 / 시료 HR-ICP-MS 30,000원 / 시료 MC-HR-ICP-MS 45,000 원 / 시료
플라스마원소분석 ICP-AES ICP-MS HR-ICP-MS MC-HR-ICP- MS Source of ions ICP ICP ICP ICP Mass analyzer Polychromator Quadrupole mass filter Magnetic sector Magnetic sector Detector Charge Coupled Device Discrete Dynode Discrete Dynode Electron multiplier + Faraday cups
Plasma 고밀도의양이온과전자를같은수로가진이온화기체 주변에서볼수있는 plasma 형광등 네온사인 번개 오로라 태양 아크용접
Inductively Coupled Plasma RF field 와 plasma support gas(ar) 를결합시킨다. 1. Radio-frequency generator 2. Load Coil : RF 파워를 plasma 로전달시키는안테나역할 3. Torch: 3 개의동심원 tube 로구성, 석영재질 Magnetic field Auxiliary gas Nebulizer gas + sample droplets Plasma Eddy current Plasma gas RF coil
Electrical and magnetic fields RF induces electrical and magnetic fields Elastic collisions cause ionization Ar + e - Ar + + e - Ar + + e - Ar 2+ + 2e - 유도결합 : 유도소자인코일을통해에너지가코일내부의하전입자로전달되는것을의미
ICP 생성원리 RF 전력이부하코일에가해진다. 아르곤가스가토치를통하여소용돌이친다. 스파크가 Ar 가스에서자유전자를생성 에어로졸시료 - 분무기의흐름이플라즈마에구멍 자유전자는 RF 장에의해가속화되어더욱이온화되고플라즈마를생성
(10000K)
Energy zones of the ICP Normal analytical Initial radiation (5500 8000 K) Preheating
Degree of Ionization * Saha Equation n 1, n a, n e : number densities of ions, atmos, and free electrons m : electron mass Za, Zi : partition functions Ei : ionization potential T is the temperature (Temp. 7500K, n e 1 10 15 cm -3 )
Atomic Spectroscopy
2D Dispersion & CCD Detection (Charge Coupled Device)
회절격자 (Diffraction grating) b c a = grating normal b = incident angle c = refracted angle a 파장이길어질수록 & 선밀도가높아질수록 반사각증가 반사회절격자 : 조밀한간격의줄쳐진또는 etching 된선들이 골을이룬거울 (600-4200 선 /mm)
Quadrupole mass filter Thomas (2001) www.spectroscopyonline.com Fast, easy, sturdy Coath (2011) Nuts and Bolts of Mass Spectrometry
Cones & lenses
Discrete Dynode Detector Consumable: 6 18 months Protect from high count rates Expensive: US$1500 2500 Light-sensitive
Magnetic Sector Mass Analyzer <Ion acceleration> <Magnetic deflection> The radius of the trajectory, r, is proportional to p/q, the ion s momentum to charge ratio. Magnetic fields are therefore momentum analyzers.
Resolving Power Q-ICP-MS has resolution 0.7 1.0 amu. HR-ICP-MS has resolving power up to 10,000 by adjusting the width of entrance and exit slits.
Electrostatic Analyzer (ESA) The radius of the trajectory, r, is proportional to mv 2 /q, the ion s kinetic energy to charge ratio. Electrostatic analyzers are therefore energy analyzers.
Double focusing
Discrete Dynode Detector
MC-ICP-MS
Faraday Cup
Secondary Electron Multiplier Coath (2011) Nuts and Bolts of Mass Spectrometry
OPTIMA ICP-OES Elan 6000/6100 Q-ICP-MS
Elan 6000/6100 Q-ICP-MS
Parr Bomb Complete Digestion
Interferences Isobaric spectral overlap Polyatomic molecular spectral overlap Polyatomic molecules from plasma gas components Molecular oxides Sample matrix/acid components Doubly charged ions Background Matrix effects Physical effects
Desolvation nebulizer APEX ARIDUS II
Ion Exchange: Why bother? 1. Keeps plasma conditions optimal for good mass bias control 2. Eliminates unwanted isobaric interferences 3. Keeps instrument clean (cones don t block up because of deposits, doesn t cause problems with lenses, etc.). Garbage into mass spec = garbage out of mass spec.
Columns
Lowering the Blank
어떤기기를사용할까? ICP- AES ICP- MS HR- ICP-MS MC- ICP-MS 시료처리속도다중이온검출농도영역 시료처리속도다중이온검출 검출한계 검출한계 ( 동위원소 ) 분석자 동위원소분석자 가격 가격
A 50-Year Record of Platinum, Iridium, and Rhodium in Antarctic Snow: Volcanic and Anthropogenic Sources Soyol-Erdene et al. (2011) ES&T Pt (fg g -1 ) Pinatubo Cerro Hudson El Chichon Ngauruhoe Rh (fg g -1 ) 25 15 5 10 8 6 4 2 0 0.8 0.4 0 Ir (fg g -1 ) 2000 1990 1980 Year (AD)
수은 분석 (1) HR-ICP-MS - d.l <0.4 pg g-1 - sample requirement <1 ml R-Hg P-Hg Hg2+ Hg0 Yeoncheol HAN (2012) Ph.D. Thesis cf) CV-AFS - without gold trap d.l ~ 0.1 pg g-1 sample requirement ~ 10 ml - with gold trap d.l ~ 0.02 pg g-1 sample requirement ~25mL Acidification (HNO3) Oxidation (BrCl, K2Cr2O7) Hg0 Hg2+ Reduction (SnCl2, NaBH4) (2) Cold Vapor(CV)-HR-ICP-MS - d.l <0.03 pg g-1 - sample requirement <3 ml Cold vapor/hydride generator (HGX-200, Cetac)
Intensifying Weathering and Land Use in Iron Age Central Africa Bayon et al. (2012) Science
Ice-sheet collapse and sea-level rise at the Bølling warming 14,600 years ago Deschamps et al. (2012) Nature