Instrument Description
The Prodigy inductively coupled plasma–atomic emission spectrometer (ICP-AES) torch box, interface, sample introduction and auto sampler components are enclosed in the ICP-AES glovebox, while the remaining components of the instrument (the monochromator, chiller, computer, and Ar supply) are located outside of the glovebox.
An analytically useful plasma is formed by causing Ar atoms to collide together in a magnetic field, yielding Ar ions and electrons. The supply of Ar is introduced into the torch via the cooling and auxiliary gases (approximately 20 L/min). A Tesla coil is used to inject a critical excess of electrons, while an rf generator supplies rf energy (KW levels at 40.68 MHz). A self-sustaining Ar plasma is formed and remains stable as long as the generator provides sufficient power and the supply of Ar is adequate. A liquid sample is introduced into the nebulizer, producing an aerosol. The aerosol passes through the spray chamber and is carried to the plasma where the aerosol particles are dried and excited/ionized by the plasma. The atomic emission from the excited/ionized sample passes through the lens of the glovebox spectrometer flange and is introduced into the monochromator. The atomic emissions are broken into their component parts by the monochromator. The photons of interest (at specific wavelengths) are detected by the solid state detector. The intensity of the emission is processed by computer software and converted into the desired units (that is, counts per second, concentration, etc.). The chiller supplies cooling water to the rf load coil during operation of the plasma.
Applications
The inductively coupled plasma – atomic emission spectrometer (ICP-AES) is used to measure trace, ultra-trace, and major quantities of metallic and nonmetallic components in various types of solutions up to a volume of 50 ML. The sample types may be from radioactive or nonradioactive sources. It is an air atmosphere glovebox that is used to determine elemental concentrations of analytes in support of programs at INL. The ICP-AES is typically used to determine concomitant elements that are difficult to do by the inductively coupled plasma – mass spectroscopy (ICP-MS), such as iron, chromium, and nickel, whose values are crucial for materials of construction (cladding, hardware, etc.).
The ICP-AES is capable of accurately measuring ppm to ppb levels depending on the element of interest.