Use of a centrifuge in solid-phase extraction is a valid platform for cleanup in the high-throughput analysis of chemical contaminants in nonfatty and fatty foods

Authors: MICHLIG, NICOLAS - Oak Ridge Institute For Science And Education (ORISE); Lehotay, Steven

Submitted to: Journal of Chromatography A
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/15/2025
Publication Date: 3/16/2025
Citation: Michlig, N., Lehotay, S.J. 2025. Use of a centrifuge in solid-phase extraction is a valid platform for cleanup in the high-throughput analysis of chemical contaminants in nonfatty and fatty foods. Journal of Chromatography A. 1749:465882. https://doi.org/10.1016/j.chroma.2025.465882.
DOI: https://doi.org/10.1016/j.chroma.2025.465882

Interpretive Summary: Chemical residues in foods must be analyzed routinely for trade and regulatory purposes worldwide, and the "quick, easy, cheap, effective, rugged, and safe" (QuEChERS) method has been the most common approach for nearly 20 years. However, QuEChERS is not ideal, and it has recently been improved using advanced technology and techniques to broaden analytical scope into the QuEChERSER mega-method. Some labs do not have the robotics needed for the modern sample cleanup step used in QuEChERSER, so this study demonstrates that an alternative centrifugal platform can be used to yield similar quality of results with less analyst expertise and lower capital and operating expense. It is expected that many more labs will now be able to use this alternate approach to cleanup in QuEChERSER to help it supplant QuEChERS as the most popular sample preparation method for chemical residue monitoring of foods.

Technical Abstract: Over the past two decades, the “quick, easy, cheap, effective, rugged, and safe” (QuEChERS) approach to sample preparation has become the most common method used in the analysis of pesticide and other residues in foods. However, many technological advancements have been made since the introduction of QuEChERS in 2003, and an updated mega-method version called QuEChERSER (which is also “efficient and robust”) was recently introduced. In addition to wider analytical scope, QuEChERSER has many other advantages over QuEChERS, such as better cleanup for improved quality of results. For example, automated robotic mini-cartridge solid-phase extraction (µ-SPE) has been shown to provide excellent cleanup prior to gas chromatography - tandem mass spectrometry (GC-MS/MS) analysis. However, not all laboratories have the resources and expertise needed to adopt the robotic method. To address this limitation, a new approach is herein introduced using centrifugal µ-SPE as a simpler and lower-cost alternative using the same commercial mini-cartridges as the robotic version. In this study, both robotic and centrifugal µ-SPE were compared for the cleanup of QuEChERS and QuEChERSER extracts of 10 commodities (avocado, blueberry, egg, mixed grains, honey, bovine kidney/liver, whole milk, black olive, spinach, and tilapia) in the low-pressure GC-MS/MS analysis of 245 pesticides and environmental contaminants. QuEChERS extracts overwhelmed the sorbents in the mini-cartridges in most cases, leading to less cleanup and worse performance in the most complex matrices, but the 4-fold more dilute QuEChERSER extracts avoided that problem. In QuEChERSER, analyte recoveries averaged 99% in all matrices using both robotic and centrifugal µ-SPE, but robotic liquid handling demonstrated better precision of 4% RSD compared to 6% using the centrifugal option. Cleanup was also slightly better using robotic automation. Laboratories may choose either option in QuEChERSER (or QuEChERS) to achieve better cleanup, analytical performance, and greater ruggedness than the dispersive-SPE format commonly employed in this application for the past 20 years.