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Vasiliy V. Rosen, M.Sc., ZBM Analytical Laboratory
www.rosen.r8.org
2012
Essential
Toxic
Major Micronutrients
Carbon (C)
Oxygen (O)
Hydrogen (H)
Nitrogen (N)
Phosphorus (P)
Potassium (K)
Sodium (Na)
Silica (Si)
Calcium (Ca)
Magnesium (Mg)
Sulfur (S)
Boron (B),
Chlorine (Cl)
Copper (Cu)
Iron (Fe)
Manganese (Mn)
Molybdenum (Mo)
Zinc (Zn)
Nickel (Ni)
Cobalt (Co)
Chromium (Cr)
Selenium (Se)
Vanadium (V)
Silver (Ag)
Aluminium (Al)
Arsenic (As)
Barium (Ba)
Berillium (Be)
Cadmium (Cd)
Mercury (Hg)
Lead (Pb)
Lithium (Li)
And all
micronutrients at
critical
concentration
The role of chemical elements in plants
(adopted from Munson R., 1997, and Macnicol R., 1984)
EA
ICP
EA – ELEMENTAL ANALYSIS OF C, H, N, S AND O
Sample state: dried, ground with a mill, 0.5-0.5 mm; or liquid
Sample weight: 2 – 3 mg
Supply: gases (He and O2 extra-pure)
EA – ELEMENTAL ANALYSIS OF C, H, N, S AND O
Sample combustion at 1020º – 1800º C
Oxidation by pure O2 to CO2, H2O, SO2, NOx
Reduction: Copper wires remove O2 and reduces NOx
to N2, SO3 to SO2
Chromatographic separation of N2, CO2, H2O and SO2
He
Catalyst - CuO
Catalyst - Cu
ATOMIC SPECTROSCOPY
After Boss. C.B. and Freden K.J. Concepts, Instrumentation and Techniques in
Inductively Coupled Plasma Optical Emission Spectrometry. 1997
E – energy difference between two levels;
h – Plank’s constant, 6.626068 × 10-34 m2kg/s;
c – speed of light, 299 792 458 m/s;
λ – wavelenght, nm
Ion Emission
Atom Emission
ICP-AES
Inductively Coupled Plasma
Atomic Emission Spectrometry
ATOMIC EMISSION SPECTROSCOPY
ICP-AES
Basics
Atomic emission spectroscopy measures the intensity of
light emitted by atoms or ions of the elements of interest at
specific wavelengths;
Inductively Coupled Plasma spectrometers use emission
spectroscopy to detect and quantify elements in a sample;
ICP-AES uses the argon plasma (6000º-10000º C) for
atomization and excitation of the sample atoms;
ICP-AES determines approximately all of the elements
except gases and some non-metals (C, N, F, O, H).
Schematic diagram of the processes in the ICP
After Spectro Gmbh, Germany
Flame (or Plasma) causes the
solvent to evaporate, leaving dry
aerosol particles, then volatilizes the
particles, producing atomic,
molecular and ionic species
ICP-AES SPECTROMETER ARCOS
ICP SPECTROMETER
Main Systems
ICP-AES: SAMPLE INTRODUCTION SYSTEM
Nebulizer (cross-flow)
Spray Chamber
Argon Supply
To Waste
Torch with Plasma
Sample
Solution
Entrance
After Manning T.J. and Grow W.P.,
1997
Inductively Coupled Plasma Source
A plasma is a hot, partially ionized
gas. It contains relatively high
concentrations of ions and electrons.
Argon ions, once formed in a plasma, are
capable of absorbing sufficient power from
an external source to maintain the
temperature at a level at which further
ionization sustains the plasma indefinitely.
The plasma temperature is about 10 000 K.
ICP-AES: PLASMA
Inductively Coupled Plasma Source
ICP-AES: PLASMA
After Spectro Gmbh, Germany
ICP-AES: RADIAL (SOP) AND AXIAL (EOP)
ICP-AES: RADIAL (SOP) AND AXIAL (EOP)
SOP: Side-on-Plasma EOP: End-on-Plasma
more suitable for hard matrices (concentrated samples);
alkali metals (Na, K, Li) calibration is more linear;
less spectral interferences;
lower sensitivity (Limit-of-Detection is higher);
more suitable for light matrices;
alkali metals (Na, K, Li) calibration is less linear;
more spectral interferences;
higher sensitivity (Limit-of-Detection is lower);
ICP-AES: OPTICS
After Spectro Gmbh, Germany; Boss. C.B. and Freden K.J. Concepts,
Instrumentation and Techniques in ICP-OES. 1997
ICP-AES: CALIBRATION CURVE
ICP-AES: SPECTRAL INTERFERENCES
Sulfur in plant sample Boron in plant sample
Sulfur in standard
(10 mg/L)
Boron in plant sample
Boron in standard
(1 mg/L)
Sulfur spectral interference on Boron line 182.6 nm
ICP-AES: SAMPLE PREPARATION
Most samples have to be prepared for analysis by ICP. Solid samples are solubilized.
Organic matter is "mineralized" i.e. converted to inorganic compounds.
Hot Plate
Microwave-assisted Digestion
Digestion Block
ICP-AES AND EA: APPLICATION
Environmental Analysis: trace metals and other elements in waters, soils, plants,
composts and sludges;
Clinical Analysis: metals in biological fluids (blood, urine);
Pharmaceuticals: traces of catalysts used; traces of poison metals (Cd, Pb etc);
Industry: trace metal analysis in raw materials; noble metals determination.
Forensic science: gunshot powder residue analysis, toxicological examination
( e.g., thallium (Tl) determination)