Energy Dispersive X-ray Spectroscopy (EDS)

Energy Dispersive X-ray Spectroscopy

Energy Dispersive X-ray Spectroscopy (EDS), also known as Energy Dispersive X-ray Analysis (EDAX or EDX), is a chemical characterization method used for the elemental analysis of a solid material. It is used to identify the elements in a sample (qualitative analysis) and determine their relative abundance (quantitative analysis) by generating EDS spectrum. It can detect elements from carbon to uranium in quantities as low as 1.0 wt% of the sample. When coupled with techniques like Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), and Scanning Transmission Electron Microscopy (STEM), EDS can provide simultaneous compositional information of the sample features.

A focused beam of electrons is directed into the specimen being analyzed in order to trigger the emission of distinctive X-rays from the object. An atom is said to be at rest when its ground state electrons, also known as unexcited electrons, are constrained to specific energy levels called electron shells. An electron in an inner shell may be excited by the incident beam, causing it to be ejected from the shell and leave an electron hole in its place. The energy differential between the higher-energy outer shell and the lower-energy inner shell may then be released in the form of an X-ray as an electron from the outer, higher-energy shell fills the hole. An energy-dispersive spectrometer can determine the quantity and energy of X-rays released from a specimen.

EDS enables the measurement of the specimen’s elemental composition since the energies of the X-rays are indicative of the energy difference between the two shells as well as the atomic structure of the emitting element. This can be used to perform point analysis, line scans, or map out the lateral distribution of elements across the SEM, STEM, or TEM imaged area. The spatial resolution of these elemental analysis areas can be as low as 10 nm, depending on the electron microscopy technique used.

Experts at Infinita Lab assist our clients based in the USA and other countries across the globe in choosing the most appropriate test strategies related to Energy Dispersive X-ray Spectroscopy, that are performed in our testing labs, to ensure that all projects are accurate, timely, and cost-effective. 

Video 01: Working of Energy Dispersive X-ray Spectroscopy (EDS)

Common Uses of Energy Dispersive X-ray Spectroscopy (EDS) 

• Surface mapping of polymer composite membranes by EDS spectrum
• Characterization of polymer Reverse Osmosis (RO) membrane
• Elemental composition and toxic effect of nanoparticles
• Detection of nanoparticles (for the improvement of the chemotherapeutic agents) in the drugs
• Detection of metal contaminants in non-small cell lung cancer
• Characterization of different isotypes of calcification in the tissues that can cause diseases
• Investigation of hazardous heavy metals in agricultural land and human tissues
• Analysis of organic to metal bonding failure modes
• Examination of gunshot residue

Advantages of Energy Dispersive X-ray Spectroscopy (EDS) 

• Non-destructive analysis technique
• The “spot” mode allows a full elemental EDS spectrum in only a few seconds
• Can be used in semi-quantitative mode to determine chemical composition by comparing a peak-height ratio to a standard

Limitations

• Energy peak overlaps among different elements in the EDS spectrum
• EDS with the Si-Li detectors protected by beryllium window cannot detect the lightest elements, typically below the atomic number 11 (Na)
• Samples must be compatible with vacuum
• The minimal detectable elemental concentration is approximately 10 ppm
• Quantitative analysis can only be performed on bulk samples with a flat surface,
• Not sensitive for elements present in concentrations < 1% by mass
• Not capable of distinguishing between ionic and nonionic species

Industries Served in the USA and Other Countries

• Metals
• Nanomaterials
• Polymers and composites
• Biomedical research and diagnosis
• Drug delivery and diagnosis
• Geology
• Forensic Science
• Thin films and membranes

Energy Dispersive X-ray Spectroscopy (EDS) Laboratories

• EAG Laboratories Inc.
• Particle Technology Labs
• Laboratory Testing, Inc.
• Microvision Laboratories, Inc.
• Atrona Test Labs, Inc.
• RTI Laboratories
• Polyhedron Laboratories, Inc

More Details

• Working principle of EDS
• Uses of EDS
• Advantages of EDS
• Limitations of EDS