2. Inductively coupled plasma-mass spectrometry (ICP-MS) is a powerful tool for
analyzing trace metals in environmental samples and several non-metals at very
low concentrations.
ICP-MS is a type of mass spectrometry that uses an Inductively coupled plasma
to ionize the sample which are then detected.
It can detect different isotopes of the same element, which makes it a versatile
tool in Isotopic labeling.
ICP-MS has greater speed, precision, and sensitivity.
3. This technology couples use of an ICP with MS for elemental analysis by
generation of ions. The ICP is involved in generation of a high temperature
plasma source at 10,000 degree Celsius,sample is passed. The elements in the
sample at such high temperature are ionized ( ICP converts the atoms of the
element in the sample into ion ) and directed further into the MS.
The ions enter into an electric field and are separtaed according to their
mass/charge ratio by MS. The MS then sorts the ions according to their
mass/charge ratio followed by directing them to an electron multiplier tube
detector. The detector then identifies and quantifies each ion.
4. - plasma is ionized by inductively heating the gas with an
electromagnetic coil.
• Plasma is one of the four states of matter. it consists of free
electrons, positive ions and neutral.
• Argon gas is electrically heated to a high temperature ( > 6000 K )
plasma.
- It is an analytical technique that measures the
mass to charge ratio of ions, and record the abundance of each ion
type
5. The process can be broken down into four stages:
• Sample introduction
• ICP torch
• Interface
• MS
6. The first step in ICP-MS is sample
introduction. There are multiple ways
in which a sample can be introduced,
and the method of introduction
depends on the physical characteristics
of the sample.
7. Samples requiring ICP-MS analysis are in a liquid form. Therefore, liquid
samples require sample nebulization. The liquid sample is pumped from a
vial,via a peristaltic pump, into the nebulizer.
If a solid sample requires analysis, the most likely method of introduction
would be via electrothermal vaporization. An electrothermal vaporizer uses
electric current to rapidly vaporize a solid sample, which can then be swept into
the ICP torch via argon gas flow.
8.
9. The ICP torch consists of a copper induction coil wrapped around a concentric
quartz structure.
Argon gas is continuously flowing throughout the quartz torch, and a radio-
frequency generator provides power. Oscillating electric and magnetic fields
are established at the end of torch and then the spark is aplies to argon it
ionizes some of the argon, and the cations and electrons produced collide with
other argon molecules during this acceleration, creating high temperatures.
The aerosol produced via nebulization enters this high temperature plasma,
where it is first dried to a solid, and then heated to a gas, referred to as
atomization. These atoms will continue to travel through the plasma, absorbing
energy until they release an electron, becoming ionized,referred to as
ionization. These newly formed ions then travel out of the torch and come to
the interface.
10. The interface can be described as the point at which sample from the ICP
portion of the instrument is introduced to the mass spectrometry (MS) portion
of the instrument. The interface portion of the instrument serves to allow the
ICP and MS portions to be coupled.
The first component after ionization in the ICP torch is the sampler cone. This
is a water cooled cone with a small orifice, allowing for the hot plasma gas to
enter a depressurizing chamber. In this chamber, rapid cooling, and thus rapid
expansion, of the gas occurs. A fraction of this gas then passes through a
skimmer cone, that is maintained at a vacuum required by MS.
11. After passing through the sample and skimmer cones, the ion stream is focused
into the quadrupole region by single ion lenses. Ions generated in plasma are
nearly all positively charged and have a tendency to repel each other. The ions
pass through a charged metallic cylinder which keeps the ion beam from
diverging.
Mass spectrometry is used to provide information about the elemental
composition of samples of matter, the structures of inorganic, organic, and
biological molecules; the qualitative and quantitative composition of complex
mixtures, the structure and composition of solid surfaces, and isotopic ratios of
atoms in samples.
12. Energetic electrons collide with analyte molecules and impart enough energy to
leave the molecules in an excited state. Relaxation then often occurs by
fragmentation of part of the molecular ions to produce ions of lower masses.
Ions are dispersed in the mass analyzer based on their mass-to-charge ratio
(m/z). Mass spectrometers require low pressures in all of the instrument
components except the signal processor and read out.
13. : water, soil, plant material
: blood: urine, serum
: nutrition
: heavy metal contamination, drug
: fuel production, radioisotopes
: rocks, sediments
: tooth, bone
: poisoning, gun shot residue
14. • Balcaen.L.,Bolea.E.,Resano.M.,Vanhaecke.F., 2015, Inductively coupled
plasma – Tandem mass spectrometry (ICP-MS/MS): A powerful and universal
tool for the interference-free determination of (ultra) trace elements – A
tutorial review, Vol 894, pp. 7-19
• Bazilio.A.,Weinrich .J., 2012, The Easy Guide to:Inductively Coupled Plasma-
Mass Spectrometry (ICP-MS), pp. 2-11
