ICP-AES.docx

. INDUCTIVELY COUPLED PLASMA-ATOMIC EMISSION
SPECTROMETRY
电感耦合
等离子体原子发射光谱法
Inductively coupled plasma-atomic emission spectrometry
(ICP-AES) is an atomic emission spectrometry method that uses
an inductively coupled plasma (ICP) as the excitation source.
An ICP is a highly ionised inert gas (usually argon) with
equal numbers of electrons and ions sustained by a
radio-frequency (RF) field. The high temperature reached in
the plasma essively desolvates, vaporises, excites - atomic
emission spectrometry (AES) detection - and ionises - mass
spectrometry (MS) detection - atoms from the sample. Detection
limits are, generally, in the lower nanogram (ICP-MS) to
microgram (ICP-AES) per litre range.
The plasma is formed by a tangential stream of support gas
through a ‘torch’, . a system consisting of 3 concentric quartz
tubes. A metal coil (the load coil) surrounds the top end of the
torch and is connected to a radio-frequency (RF) generator.
Power (usually 700-1500 W) is applied through the coil and
an oscillating ic field corresponding to the frequency
of the generator (in most cases 27 MHz, 40 MHz) is formed.
The plasma forms when the support gas is made conductive
by exposing it to an electric discharge, which produces seed
electrons and ions. Inside the induced ic field, the
charged particles (electrons and ions) are forced to flow in a
closed ann