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This application note demonstrates how LECO’s GDS900 can be utilized to characterize carburized steel using the standard low alloy steel method for bulk analysis.

Steel Carbon Gradient Characterization with Spectroscopy

http://www.spectroscopyonline.com/spec_w/virtual

 magazine and the Society for Applied Spectroscopy (SAS) are pleased to present a joint virtual conference on February 23 and 24, 2021, called “Atomic Spectroscopy in Practice.” This two-day event will provide highly practical information for atomic spectroscopists and analytical laboratory staff working with molecular atomic techniques.

The first day, February 23, will cover sample preparation, atomic absorption (AA), and inductively coupled plasma-optical emission spectroscopy (ICP-OES) and ICP–mass spectrometry (ICP-MS).

THE second day, February 24, will cover X-ray fluorescence, laser-induced breakdown spectroscopy (LIBS), and laser-ablation ICP-MS (LA-ICP-MS).

Each day, there will be a morning session and an afternoon session. The morning sessions will provide a series of tutorials on fundamentals and troubleshooting, followed by a question-and-answer (Q&A) period with all of the speakers. In the afternoon sessions, leading instrument suppliers will give 20-minute talks providing educational troubleshooting and tips-and-tricks.

The event will also include a special award plenary for the 2021 Emerging Leader in Atomic Spectroscopy, with a talk by this year’s winner, L. Robert Baker of the The Ohio State University.

All attendees will receive a certificate of completion from the Society for Applied Spectroscopy.

Tuesday, February 23: Sample Preparation, AA, and ICP Techniques

Laura Bush, Editorial Director, Spectroscopy

Introduction to Sample Preparation for Spectrochemical Analysis

This introductory session will offer both theory and practice of sample preparation methods for spectrochemical analysis (AAS, ICP-OES and ICP-MS). The conventional thermal methods (hot plate, dry ashing, fusion) as well as microwave-assisted digestions, and high-pressure high temperature acid digestions will be covered. The chemical and physical underpinnings of sample decomposition will be discussed. The participants will learn about how to minimize the background element concentrations and contaminant control, practical hints as well as safety issues. The session is an ideal starting point for beginners. Key learning objectives include:

Learn about various sample decomposition methods available for spectrochemical analysis.

How does sample digestion work? Learn about the chemical and physical basis.

How to determine the effectiveness of decomposition.

How to achieve low backgrounds and contaminant control and safety concerns.

Learn about sample preparation hints, pitfalls, and safety issues.

Introduction to Atomic Absorption Spectroscopy

This session will cover recent advances in analytical atomic spectroscopy including flame atomic absorption spectroscopy (FAAS), hydride generation (HG)-AAS, cold vapor(CV)-AAS, graphite furnace AAS (GF-AAS), and atomic emission spectroscopy (AES). Course content includes fundamentals, theory, instrumentation, practice, troubleshooting hints, as well as common applications. Analytical merits and limitations of each method will be presented. Key learning objectives include:

What’s in that box? We will learn about the theory, basic instrumentation, and practice of flame AAS, AES, (HG)-AAS, (CV)-AAS and GF-AAS.

How to choose suitable instruments conditions and how to remove potential spectral and chemical interferences.

Will learn about calibration approaches for quantitative analysis.

Introduction to ICP-OES and ICP-MS: Key Concepts, Processes and How They Affect Signals, Capabilities, and Potential Sources of Error

The (simple) fundamental processes that control ICP-OES (optical emission) and ICP-MS (mass spectrometry) signals will be described including conversion of samples to atoms and ions, excitation and light emission, and ion transport from the ICP through the mass spectrometer. How each process affects ICP-OES and ICP-MS signals (related to a corresponding component of the instrument) and how the sample itself can affect the fundamental processes, and therefore, signal intensities will be considered. Spectral overlaps and matrix effects that can affect analysis accuracy will be discussed.

Leading instrument suppliers give educational 20-minute talks providing troubleshooting and tips-and-tricks

Wednesday, February 24: XRF, LIBS, and LA-ICP-MS

X-ray Fluorescence Spectrometry with Emphasis on Field Applications

This session will start with brief description of X-ray fluorescence (XRF), including how it originated and then evolved from large laboratory setups into portable, handheld devices. Then it will highlight features and limitations of handheld XRF, followed by overview of its main applications. It will also discuss common misconceptions and typical mistakes associated with use of handheld XRF devices.

Overview of Qualitative XRF with Application Examples from Cultural Heritage and Archaeology

X-ray fluorescence (XRF) spectrometry is a simple, nondestructive technique that provides valuable elemental information for a wide range of industries and areas of research. This presentation will provide an overview of XRF spectrometry with an emphasis on qualitative analysis. It will start with a tutorial on qualitative analysis via XRF, including spectral interpretation and interferences. This will be followed by a discussion of different data analysis approaches. The final part of the talk, drawing on the speaker’s years of research experience in cultural heritage analysis and archaeology, will emphasize applications of XRF spectrometry. Examples will include sample types such as glass tesserae and fabrics, pairing of XRF spectrometry with other instrumental methods, and different instrument designs such as portable XRF and micro-XRF.

Laser-induced Breakdown Spectroscopy: From Plasma Formation to Actionable Results

This session will guide the participants through an analysis concept to completed measurement and will focus on identifying measurements for which LIBS is not simply acceptable, but ideal. Topics to be covered include:

           -What is local thermodynamic equilibrium and why does it matter?

           -Beyond the raw spectra to concentrations, trends, depth profiling and imaging

Two use-cases that highlight the use of LIBS above other analytical techniques.

Laser Ablation ICP-MS: A Review of Fundamentals and Applications

This session will provide an introduction to the science behind laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS), including an overview of various instrumental components. The fundamentals will be illustrated with examples of practical applications of the technique.

Special Award Plenary: The Emerging Leader in Atomic Spectroscopy Award

Visualizing Charge and Spin Dynamics Using Ultrafast XUV Spectroscopy

L. Robert Baker, The Ohio State University

The need to characterize materials and devices that enable new technologies is pushing the boundaries of atomic, molecular, and material spectroscopies. For example, at the heart of energy conversion and information processing is the need to control charge and spin transport at interfaces. Many artificial systems rely on heterogenous catalysts to accomplish at surfaces what nature does using molecular assemblies, making it important to understand the material properties and surface states that mediate electron dynamics at interfaces. Despite its importance, the ability to directly measure charge and spin dynamics on the ultrafast time scale with chemical-state resolution remains a significant challenge, requiring the development of new spectroscopic tools. Toward this goal, we have developed extreme ultraviolet reflection-absorption (XUV-RA) spectroscopy as a surface-specific analog of X-ray absorption spectroscopy. This talk focuses on the development of this method and its recent applications, which range from directly observing charge separation at catalytic interfaces to studies of ultrafast spin state switching in magnetic semiconductors.

On demand available after final airing until Feb. 24, 2022

: CEM, Glass Expansion, Leco, Milestone, Millipore Sigma, Tofwerk, Rigaku

Webcasts

***Live: Tuesday February 23, 2021 & Wednesday February 24, 2021*** Spectroscopy magazine and the Society for Applied Spectroscopy (SAS) are pleased to present a joint virtual conference on February 23 and 24, 2021, called “Atomic Spectroscopy in Practice.” This two-day event will provide highly practical information for atomic spectroscopists and analytical laboratory staff working with molecular atomic techniques. *** On demand available after final airing until Feb. 24, 2022***

Atomic Spectroscopy in Practice: A Joint Virtual Conference Presented by Spectroscopy Magazine and The Society for Applied Spectroscopy

GD-AES Calibration: General Considerations

Spectrochemical analysis is a comparative technique; therefore, unknown samples are best analyzed against reference materials of similar composition. Certified reference materials (CRM) and reference materials (RM) are used to establish the relationship between concentration or mass ratio and light intensity or instrument response under precisely controlled lamp parameters. LECO calibrations employ reference materials that are traceable to or certified by NIST or other internationally recognized certifying bodies (ISO Guide 31).

	LECO Glow Discharge uses a Grimm-style lamp for atomic emission spectrometry. It is a nonthermal, cathodic sputtering device that sputters material from the sample surface; available in 4 mm anode diameter with 15 mm o-ring vacuum seal and 2 mm diameter (obtainable in two versions: large lamp, 15 mm o-ring, vacuum seal; and small lamp, 7 mm o-ring, vacuum seal). The sample is externally mounted on the vacuum seal o-ring. Sputtering is initiated when a high negative potential is applied under conditions of a partial pressure that includes a controlled supply of an easily ionized gas (argon). Argon ions impinge on the surface of the specimen removing atoms and small atomic clusters which may be dissociated into individual atoms. When excitation of the atoms or less frequently of ionic species occurs, a photon of light is emitted at a wavelength characteristic of the element from which the excited particle originated.

GD-AES Calibration: Considerations for Bulk Analysis

	Choice of calibrants is crucial in forming robust working curves. Sufficient specimens must be chosen to reliably satisfy the entire concentration range for every element to be determined. The calibrants are measured at three locations around the piece, at minimum, to incorporate the uncertainty of the specimen on the working curves. 

	Most working curves are linear over a long dynamic range of concentration. Curve linearity allows accurate extrapolation even outside of the limits of the calibration range.

	Instrument response can be accurately measured on array detectors or photomultiplier tubes (PMT).

GD-AES Calibration: Considerations for Quantitative Depth Profile Analysis

	Quantitative depth profile (QDP) is used to measure discreet layers or diffusion gradients from the surface into the substrate of a specimen. QDP employs a sputter rate corrected calibration using bulk reference materials. Strict control of voltage and current are required in order to maintain constant relationships between sputter rates of different materials. Data is collected simultaneously on all channels as intensity versus time. Depth is calculated using material density and lamp geometry. There is no need for material specific thickness standards or expensive auxiliary equipment such as a profilometer in order to create a calibration.

	Sputter rate is a material constant. If Sample A has a sputter rate of 4 and Sample B sputters has a sputter rate of 1, Sample A would yield a signal four times higher than Sample B for the same concentration of a given analyte.

	Sputter rate corrected calibration is required to create usable working curves. Signal intensity for an element is proportional to the concentration in the plasma rather than in the sample. Since the various alloys sputter at different rates, each family tends to group to itself. No single working curve can be made and quantification is not possible without correcting for the sputter rate differences. The inclusion of the sputter rate allows all the families to fall on a linear working curve.

	An example of a simple depth profile is a binary system such as zinc on steel, Figure 1 (original Figure 6). Data is collected starting at the surface of the specimen:

	Zn â 100% and Fe â 0%. As sputtering continues through the galvanized coating and into the steel substrate, the concentration of Zn decreases and the concentration of Fe increases. Both matrices must be calibrated so that the working curves span from traces to 100%. Additional elements should be calibrated to cover the range expected in either matrix.

	Factory calibrations are possible for a wide range of materials including:

	
• Galvanizingâhot dipped, electrogalvanized,

	
• Galvannealed, Zn-Ni, Zn-Al, and so on,

	
• ElectroplatingâAu, Cu, Ni, Cr, and so on,

	
• Heat treatmentsâcarburized, nitrided, carbonitrided, nitrocarburized

	To read the application note in its entirety, go to 

	3000 Lakeview Avenue, St. Joseph, MI 49085

Spectrochemical analysis is a comparative technique; therefore, unknown samples are best analyzed against reference materials of similar composition.

LECO Corporation

Articles

Steel Carbon Gradient Characterization with Spectroscopy

Atomic Spectroscopy in Practice: A Joint Virtual Conference Presented by Spectroscopy Magazine and The Society for Applied Spectroscopy

Understanding Calibration for Glow Discharge Atomic Emission Spectrometry (GD-AES)