Understanding the Journey from Lab-Based to Handheld XRF Technology

The landscape of analytical technology has undergone a remarkable evolution over the years, and one significant transformation has been the extension of traditional lab-based X-ray fluorescence (XRF) systems to revolutionary handheld XRF devices used in the field. This shift has changed the paradigm for industries, enabling them to perform rapid on-sight and accurate material analysis.

Let’s explore the journey of XRF technology, from lab-based systems to handheld analyzers, and uncover the advantages, applications, and transformative impact industry.

Lab-based XRF: From theory to practice

In 1913, Henry Moseley laid the foundations for chemical analysis using XRF by investigating the X-ray spectra of various elements.¹ Over three decades later, in 1948, the first commercial X-ray spectrometer hit the market. However, XRF spectrometry would take another decade to establish itself as a mainstay for chemical analysis.²

During the early years, technological restraints confined XRF systems to the laboratory. Nonetheless, the technique was praised for its precision and accuracy, offering invaluable insights into the composition of materials especially for analyzing metals, alloys and geological samples.

The powerful insights provided by XRF were still largely unavailable for industrial users due to high costs, the skill level required to operate XRF systems, and the need to take samples, transport them to a lab, wait for analysis and then feed the results back into the process hours, days or even weeks later. Overall, the lack of mobility meant that it was still a challenge to use XRF to make immediate, informed decisions in the field.^4,5

Portable XRF analysis: From the laboratory to the field

Enter portable XRF instruments in the mid-1960s; the mobile technology would go on to become a groundbreaking solution that revolutionized material analysis. The first field portable XRF system wasn’t designed to be taken up by a large customer base, which is often the case with novel technologies. The attractiveness of early field XRF instruments was likely inhibited by a lack of true portability and poor user-friendliness.⁶ Nevertheless, these comparatively compact devices carried the laboratory to the field, eliminating the need for sample transportation and providing on-the-spot results.

Used in industrial plants and mines on a range of materials, the advantages that portable XRF analysis brought were manifold.⁶ Costs associated with sampling and subsequent lab analysis were eliminated, operational downtime was reduced, and industries gained the ability to make quick decisions based on accurate analysis.⁵

In 1983, a “hand-portable” XRF analyzer was produced that improved on the abilities of first-generation portable models. This model required users to have considerable technical training and a sound knowledge of XRF techniques.⁶ Though portable and even handheld, field XRF analyzers in the 1980s still came with at least two parts, one probe containing a radioactive isotope along with the detector and one processing unit, and the analyzers were generally dedicated to a single application.

Honing handheld XRF analysis

Between 1980 and the 2000s, the development of energy dispersive detectors and the use of multiple radioactive isotope source emitters enabled multi-element analytical capabilities, though detection ranges were limited to elements with atomic numbers above potassium.

As analyzers with new sources gained traction and the US EPA introduced the Standard Method 6200, field portable XRF was established as an accepted analytical method for elemental screening. However, it was ultimately the demand for effective on-site scrap metal sorting that spurred the development of lightweight analyzers and drove down unit prices.⁷

In 1994, the first single unit, handheld XRF analyzer was developed. The Niton XL-309 XRF analyzer with silicon PIN diode detector provided real-time digital signal processing and could measure elements as light as titanium. At just 2.5 pounds, it offered enhanced analytical performance at a lower price point than previous XRF instrumentation.

The proceeding decades would witness rapid technological developments. Miniaturized X-ray tubes would replace radioactive source emitters for nearly all handheld devices, providing superior performance, increasing safety for users, and reducing requirements for regulatory compliance. Advances in detectors would bolster the analyzers’ elemental range such that multi-application analyzers would become commonplace.

Today, handheld XRF analysis is the standard technique for fast and accurate elemental characterization in industrial environments; operators can now make confident decisions on-site without delay. The industrial environments benefiting from XRF range from scrap metal recycling and metal fabrication to mining, power generation, automotive and aerospace, among others. Current handheld XRF analyzers are capable of detecting elements at trace levels and rivaling the sensitivity of laboratory XRF systems. Modern analyzers can also measure light elements, such as Mg, Al, P and Si.⁸

In the latest generation of devices, a user-friendly interface ensures that users with varying levels of expertise can easily operate the analyzers and generate high-quality results. The gap between lab-based and handheld systems has significantly narrowed, making the latter a favorable choice for a wide range of applications.⁸

Empowering industry: The evolution of handheld XRF technology

The journey from lab-based to handheld XRF  marks a revolutionary milestone in analytical capabilities as the technology has been made available to a much broader group of users. Initially, only laboratory personnel could utilize the power of XRF technology, but advancements have put that power in the hands of industrial operators as well. The high accuracy, ease of use and low cost of handheld analyzers have expedited decision-making, optimized costs, and improved operational efficiency across industries.

Whether in mining, manufacturing, recycling, or material analysis, the transformative impact of XRF analysis is undeniable.

References and further reading

1. Moseley HGJ. (1913). XCIII. The high-frequency spectra of the elements. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science. https://doi.org/10.1080/14786441308635052
2. Bain DC, et al. (1994). X-ray fluorescence spectroscopy and microanalysis. Clay Mineralogy: Spectroscopic and Chemical Determinative Methods. https://doi.org/10.1007/978-94-011-0727-3_7
3. Borges CS, et al. (2020). Comparison of portable X-ray fluorescence spectrometry and laboratory-based methods to assess the soil elemental composition: Applications for wetland soils. Environmental Technology & Innovation. https://doi.org/10.1016/j.eti.2020.100826
4. Specht AJ, et al. (2019). Comparison of bone lead measured via portable X-ray fluorescence across and within bones. Environmental Research. https://doi.org/10.1016/j.envres.2019.02.031
5. Karttunen JO, et al. (1964). A Portable Fluorescence X-ray Instrument Utilizing Radioisotope Sources. Analytical Chemistry. https://doi.org/10.1021/ac60213a027
6. Rhodes JR, et al. (1983). Application of a microprocessor-based portable XRF analyzer in minerals analysis. The International Journal of Applied Radiation and Isotopes. https://doi.org/10.1016/0020-708X(83)90134-5
7. Lemière B. (2018). A review of pXRF (field portable X-ray fluorescence) applications for applied geochemistry. Journal of Geochemical. https://doi.org/10.1016/j.gexplo.2018.02.006
8. ThermoFisher Scientific. Niton™ XL5 Plus Handheld XRF Analyzer. Available at: https://www.thermofisher.com/order/catalog/product/NITONXL5PLUS?SID=srch-srp-NITONXL5PLUS (Accessed on 17 August 2023).
9. ThermoFisher Scientific. How Does LIBS Work?. Available at: https://www.thermofisher.com/uk/en/home/industrial/spectroscopy-elemental-isotope-analysis/portable-analysis-material-id/industrial-elemental-radiation-solutions/how-does-libs-work.html#:~:text=LIBS%20is%20an%20acronym%20for,electronically%20excited%20atoms%20and%20ions (Accessed on 17 August 2023).
10. ThermoFisher Scientific. XRF Drives Coating Analysis in the Automotive Industry. Available at: https://www.thermofisher.com/blog/metals/xrf-drives-coating-analysis-in-the-automotive-industry/#:~:text=Handheld%20XRF%20analysis%20also%20helps,control%20or%20cost%20control%20standpoint (Accessed on August 17 2023).