13 [email protected] neutron activation analysis (naa)
TRANSCRIPT
SPECTROSCOPYUVi-Vis (Ultra Ungu-Tampak)AAS (Absorpsi)AES (Auger Electron)RAMANMOESBAUERNMR (Nuclear Magnetic Resonance)FTNMRESR (Electron Spin Resonance)PHOTOACUSTICMS (Mass)EIS (Electron Impact)ISS (Ion Scattering)XPS (Xray Photoelectron)UPS (Ultraviolet Photoelectron)
SPECTROPHOTOMETRYUV-VisIRFLUORESCENCEPHOSPHORESCENCE
RADIOCHEMICAL/ NUCLEAR METHOD:Radioactive Tracer SpectrometrySpectrometry/LSC (Liquid Scintillation Counter)NAA (Neutron Activation Analysis)Mosbauer
THERMOMETRIC METHOD-DTA-DTG
OTHER METHODS
SPECTROMETRYFLAME EMISSIONATOMIC ABSORPTIONXRFNUCLEAR METHOD (,,)MS (MS/MS,ICP-MS,GC-MS,LC-MS,LC-MS-MS, IMS)
CHROMATOGRAPHYGCLCHPLCTandem: GC-MS, LC-MS, LC-MS-MS
ELECTROMETRIC METHODpH/ISEPotentiometric TitrationVoltammetryPolarography (PDV,DME,DPP)Electrogravimetry and CoulometryConductometry
CHEMICAL ANALYSIS OF SURFACESISS (Ion Scattering Spectrometry)SIMS (Secondary Ion Mass Spectr.)AES (Auger Emission Mass Spectr.)ESCA (Electron Spectroscopy for Chemical Analysis)
PENGGOLONGAN METODEANALISIS INSTRUMENTAL KIMIA
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TEKNIK ANALITIK NUKLIR
PENGUKURAN LANGSUNGRADIOAKTIVITAS
(, dan )
PENGUKURAN TIDAK LANGSUNGMETODE AKTIVASI -LANGSUNG (prompt): PGNAA, PIXE -KASEP (delayed): NAA, CPAA, PAA -IBA: NRA, PIGE, RBS, PIXE
PENAMBAHAN PERUNUT RADIOAKTIF
P ENGGUNAAN SUMBER RADIASI -ABSORPSI: Radiasi: , dan neutron -ANALISIS HAMBURAN (scattering) -PENDAR : PENDAR SINAR (XRF)
Gambar 1: Skema teknik analisis nuklir (TAN)
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DATA RADIOAKTIVITAS
DATA KADAR UNSUR/LOGAM
-Jenis sampel padat, cair, gas-Tidak memerlukan perlakuan kimia-Tidak terkontaminasi -Analisis unsur serentak (Multiunsur)-Memiliki sensifitas & selektivitas tinggi-Mampu menganalisis unsur orde μg, ng-Dll
Keunggulan Analisis Aktivasi Neutron
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NEUTRON ACTIVATION ANALYSIS
A+1X
A+1YZ+1
XAZ
NEUTRON INTERACTION OFTEN PRODUCES RADIOISOTOPES : ENTIRE PERIODIC TABLE
CHARACTERISTIC RADIATIONS, e.g., GAMMA RAYS ARE MEASURED : CONCN. OF ISOTOPES (ELEMENTS)
NAA
PGAA
• For neutron induced reactions
VC=0
• It enters all nuclei and binds to it.
• CN is in excited state.
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Figure 2: A typical reactor neutron energy spectrum showing the various components used to describe the neutron energy regions.
• Although there are several types of neutron sources (reactors, accelerators, and radioisotopic neutron emitters) one can use for NAA, nuclear reactors with their high fluxes of neutrons from uranium fission offer the highest available sensitivities for most elements. Different types of reactors and different positions within a reactor can vary considerably with regard to their neutron energy distributions and fluxes due to the materials used to moderate (or reduce the energies of) the primary fission neutrons. However, as shown in Figure 2, most neutron energy distributions are quite broad and consist of three principal components (thermal, epithermal, and fast).
Neutrons
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Slide#8
The Kartini Facilities• TRIGA Mark II Reactor (100 kW)• Neutron Radiography (in experient)• Thermal Neutron Activation Analysis• Fast Neutron Activation Analysis (14 MeV in experient)• Prompt Gamma Activation Analysis (in experient)• Spectroscopy (a, b, and g)• Radiation Handling Areas• Computational Capabilities : AccuSpec, Shampo,
Maestro and Genie software• Gamma Detector: NaI(Tl), HPGe, Ge(Li)
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Sistem iradiasi dg rabit system/pneumaticREAKTOR KARTINI
REAKTOR KARTINITRIGA MARK II, 100 kW
Spektrometer 13 Maret015 [email protected]
Activation methoddelayed (AAN)
TOTAL ELEMENTS AMENABLE TO NAA > 70
FNAA
S
CONV. NAA and PGNAA : DL 0.01-1000 ppb13 [email protected]
Limit Deteksi dalam ppb (10-9)
ELEMENT DETECTION LIMIT [g]
In, Eu, Dy 10-13 to 10-12
Mn, Lu 10-12 to 10-11
Co, Br, I, Sm, Ho, Hf, Re, Ir,Au, Th, U
10-11 to 10-10
Na, Cl, Cu, Ga, Ge, Se, As, PdSb, Te, Yb, Ta, W, Pt
10-10 to 10-9
K, Sc, Ni, Rb, Sr, Y, Nb, Ru, Cd Sn, Gd, Tb, Tm, Os, Hg
10-8 to 10-9
* CALCULATED USING A NEUTRON FLUX OF 1013n/SEC/Cm2 & A 20% RELATIVE EFFICIENCY DETECTOR
DETECTION LIMITS DEPENDS ON FLUX, DETECTION EFFICIENCY AND IRRADIATION TIME
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Perbandingan Limit Deteksi berbagai Metode
METODE LIMIT DETESI
AAS 10-6 – 10-9 gAES 10-6 – 10-7 gFLAME EMISSION 10-6 – 10-9 gANODIC STRIPP. VOLTAMETRY 10-8 – 10-9 gMASS SPECTROMETRY 10-6 gICP-MS 10-9 gGAS CHROMATOGRAPHY 10-6 – 10-7 gXRF 10-5 – 10-7 gNAA 10-5 – 10-10 gIBA 10-6 – 10-9 g
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14 MeV-NAA : FNAANEUTRON GENERATOR : Cockroft-Walton accelerator principle
NEUTRONS OF ~14 MeV FROM t(d,n) RXN
AVAILABLE FLUX: 109 n.cm-2.s-1 from a neutron yield of 2.5x1011 n.s-1
Threshold reactions:(n,p), (n,2n), (n,) etc.
Inelastic scattering rxns (n,n’): C, O and N
(200, 100 and ~20 mb respectively)Determination of many elements including C, N and O possible
Important tool for detection of explosives (TNT, RDX etc.): high C, N, O
high N/O and/or C/O ratio
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Element Nuclear Reaction Product Half-life Gamma-ray (keV)
O 16O (n, p) 16N 7.13 s 6130, 7120
N 14N (n, 2n) 13N 9.97 min 511
F 29F (n, p) 19O 30 s 197.4
Mg 24Mg (n, p) 24Na 15 h 1368.5
Si 28Si (n, p) 28Al 2.24 min 1779
P 31P (n, ) 28Al 2.24 min 1779
Fe 56Fe (n, p) 56Mn 2.58 h 847
Cu 63Cu (n, 2n) 62Cu 10 min 511
Zn 64Zn (n, p) 64Cu 12.8 h 511
Zr 90Zr (n, 2n) 89mZr 4.18 min 588
Th Fission - Delayed neutron
U Fission - Delayed neutron
14 MeV-NAA : FNAA
PGAA WORK INVOLVED
SETTING UP OF A SYSTEM: DETECTION & SHIELDINGCHARACTERISATION OF THE NEUTRON BEAMEFFICIENCY DETERMINATION (~ 0.1-10 MeV) DETERMINATION OF PROMPT k0-FACTORSANALYTICAL APPLICATION
PGNAA is an online technique : Measurement of capture gamma rays after neutron absorption
1. It is complementary to conventional NAA2. Analysis of low Z elements (H, B, C, N, Si, P,S):
Best for H and B analysis3. Determination of many elements including Hg, Cd,
Sm & Gd
The k0-based PGNAA: Advantageous
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Some important features of PGNAA
• Ability to determine light elements (H,B,N,C,P,S,Si)
Analysis of biological sample
• Ability to determine toxic elements (Cd, Hg) with high
sensitivity
Environmental samples
• Nondestructive multielemental bulk analysis
• Flexibility of sample size and shape
Archeological, geo- and cosmo- chemical samples
• Isotopic analysis is possible (S,Si,Ni)
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Neutron beam line
Lead shield
Boron CarbideHPGe
detector
Beam Dump
Sample Holder
Schematic representation of the PGNAA set up
BGO shield
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WORK• SETTING UP PGNAA SYSTEM
• CALIBRATION & CHARACTERISATION
• k0 FACTORS
• BACKGROUND PROBLEMS
• CAPTURE GAMMA RAYS IN 60Co
• APPLICATIONS
A) ANALYSIS OF SAMPLES CONTAINING B,Cd,Gd,Hg
B) ANALYSIS OF A FEW CRMS
C) ANALYSIS OF METEORITES
D) ANALYSIS OF SS ALLOYS
JRNC 250 (2001) 303, NIMA 457 (2001) 180NIM A 516(2004)143, ANAL CHIM ACTA ( COMM), ANAL CHEM ( PREP)13 Maret015 [email protected]
Substance H C N O Cl C/O C/N Cl/O
Plastics M-H H H-L M M-N M VH -
Narcotics H H L L M H, >3 H VH
Explosives L-M M H VH M-N L, <1 L, <1 L-M
L – Low, M – Medium, H – High, VH- Very high
Elemental densities and ratios of three classes of substances
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NAA
k0-BASED NAASINGLE COMPARATOR: Au
DETMN: f , & k0
VALIDATION: CRMs
k0-BASEDINTERNAL MONO STANDARD NAA
IN-SITU REL-EFFICIENCYLSNAA
STANDARD-LESS NAA
k0-BASED PGNAA
EFFICIENCYk0-FACTORS
APPLICATIONS
APPLICATIONSReference materials,
Ruby, Emerald, Sediment,Leaf, Cereal, Mn-NodulesSerpentines, Zircaloy, SS,
Aluminium, Meteorites
Chemical NAA, Radiochemical NAA
Speciation NAA
R & D WORK ON NAA
Collaborations
Development ofMethodologies:
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RADIOACTIVITY MEASUREMENT
RADIOACTIVITY IN ENVIRONMENT1. ESSENTIALLY NATURAL PROCESSES, e.g., RADON & DP2. ANTHROPOGENIC : MINING, PROCESSING, REPROCESSING
DIAGNOSTIC, TESTING, ACCIDENTS
AS ON NOW FIRST IS MUCH MORE
RADIOACTIVITY MEASUREMENTS : , , LARGE SAMPLES OF SOIL, WATER; AIR PARTICULATES COLLECTED ON FILTERS; FOOD STUFFS CHEMICAL PRECONCENTRATION
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Toxicity depends on species
The five major species: As(III), As(V), MMA, DMA and AsB
In natural water two major species: As(III) & As(V)
Drinking water limit (As): 10 ng.mL-1 (WHO)
SPECIES OF ARSENIC
ARSENIC SPECIES:WATER SYSTEM
Standardized two chemical separation methods:
(i) Ion exchange separation(ii) Solvent extraction
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INORGANIC ARSENIC SPECIATION: Dowex 1X8 in acetate form
As(V)
As(V)
As(V)
As(III)+As(V)IN 8M AcOH 0.12M HCl
As(III)
TOTAL ARSENIC IN DRINKING WATER BY INAA: 20-650 ng.mL-1 in samples from Kolkata city
• PERCENT RECOVERIES
OF ARSENIC SPECIES QUANTITATIVE (96-100%) IN BOTH ION EXCHANGE AND SOLVENT EXTRACTION METHODS
• SOLV.EXT.: APDC-MIBK IN pH 1-5.5
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