What is WDXRF, in simple terms?

WDXRF (Wavelength Dispersive X-ray Fluorescence) is a method that uses X-rays to identify the elements in a sample. First, the instrument directs X-rays at a sample, which excites the atoms inside it. When these atoms lose that excess energy, they emit characteristic fluorescent X-rays, each with a specific wavelength unique to each element. These X-rays are diffracted using crystals, which separate them by wavelength and are analyzed one at a time to determine which elements are present in the sample and their concentrations.

What kinds of problems is WDXRF designed to solve?

WDXRF is designed to detect the presence of elements ranging from beryllium to uranium in a material and in what amounts. It is used when there is uncertainty about what a material is made of, or when the exact composition needs to be confirmed to avoid quality, safety, or compliance issues. For example, it can verify that cement or metal alloys contain the correct ingredients before they are used or shipped. It is commonly used to ensure quality, meet regulatory requirements, and detect impurities in industries where knowing the exact elemental composition is critical.

What types of materials are best suited for WDXRF?

WDXRF works well with a wide range of material types, including solids, powders, and liquids. Powders and solid samples are generally the easiest to analyze and provide very reliable results when prepared correctly (for example, pressed pellets or fused beads). Liquids can also be analyzed, but they can be more challenging due to absorption effects, especially for lighter elements. In these cases, alternative preparation methods can improve performance. Overall, the technique is flexible, but success depends heavily on using the correct sample preparation method for the material.

What are the main advantages of using WDXRF?

A key benefit of WDXRF is that it is non-destructive, meaning the sample stays intact after analysis and can still be used for further testing. It also requires relatively simple sample preparation compared to other methods and offers strong reproducibility and repeatability, which makes it reliable for routine testing. The technique can measure a wide range of elements, from parts per million up to high percentages. Another strength is its ability to separate signals from similar elements, which helps avoid overlap errors.

What are the limitations of WDXRF?

Compared to other elemental analysis techniques, such as ICP (Inductively Coupled Plasma), WDXRF is less sensitive for detecting extremely low concentrations of elements (such as parts per billion, or ppb). As a result, it has higher detection limits compared to ICP and may not be the best choice when trace -level measurements (ppb levels) are required. The system also requires a relatively large lab footprint, along with supporting systems like gases or vacuum conditions. The accuracy of the results also depends heavily on how well the sample is prepared, and some types of samples, such as liquids, can be more difficult to analyze.

What are matrix effects?

Matrix effects occur when the elements in a sample influence each other during analysis. Instead of each element behaving independently, they can interact in ways that change the signals being measured. In WDXRF, the overall composition of the material affects how X-rays are absorbed and emitted, so the intensity measured for one element can be influenced by the presence of others. As a result, the signal is not always directly proportional to concentration, and corrections are required to ensure accurate results.

How important is the fundamental parameters (FP) method?

Fundamental parameters (FP) is a semi-quantitative method in WDXRF that uses physical constants and the sample’s matrix to model X-ray interactions, instead of relying only on matching calibration standards. The FP database provides the physical constants and interaction data used to convert measured signals into element concentrations. This makes it possible to analyze a wide range of materials without needing a large number of physical calibration standards for every possible composition.

What does the accuracy of the FP method depend on (assuming proper sample preparation)?

In general, the accuracy of the FP method depends on how well the model and FP database represent the sample. While proper sample preparation is important, the composition of the sample itself also plays a major role. Because this method is matrix-based, accuracy can vary depending on the elements present and how they interact. In general, better accuracy is typically seen for heavier elements in lighter matrices.

What industries rely most on WDXRF today?

WDXRF is widely used in many industries where it is critical to know exactly what materials are composed of. These industries include cement production, mining, metals and alloys, batteries, ceramics, environmental testing, petrochemicals, and pharmaceuticals, where accurate composition data is essential to maintain quality, meet regulations, and avoid costly errors.

WDXRF on Your Wavelength

WDXRF on Your Wavelength is a monthly LinkedIn Live session where we will answer your questions about Wavelength Dispersive X‑ray Fluorescence (WDXRF).

Each session features Shiv Verma, an XRF Application Specialist at Rigaku, who will answer questions from the audience. Whether you’re new to WDXRF or have been using it for years, you are welcome to join the discussion, listen in, and learn from questions others are asking.

You can find recaps and watch the recordings from previous sessions below.

Feel free to ask questions for the next session or join us live on the LinkedIn Live event page.

Posts by Shiv Verma

Shiv Verma

Shiv Verma, PhD, is an XRF Applications Scientist at Rigaku Americas, bringing more than a decade of experience in elemental and compositional characterization. His expertise helps generate accurate, reliable data that organizations can trust, enabling better decisions around product quality, process control, and regulatory compliance. He specializes in X-ray fluorescence spectroscopy (EDXRF and WDXRF), ion beam analytical methods, and the development of Certified Reference Materials (CRMs) that support method validation, quality assurance, and traceability. At Rigaku, he supports customers through application development, performance optimization, and technical training, ensuring confident, day-to-day use of WDXRF spectrometers. With a Ph.D. in Physics and a background in advanced X-ray spectroscopy, he combines deep technical expertise with a hands-on approach, bridging fundamental science and real-world applications to turn complex measurements into accurate, actionable insights.

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