Background: Economically motivated adulteration (EMA) of foods has become an increasing concern in recent years, with lemon juice as a popular target. Objective and method: In this work, an optimized preparation procedure for the isolation of citric acid fronm lemon juice was validated using elemental abnalyzer-isotope ratio MS (EA-IRMS) to detect adulteratiobn with exogenous citric acid. Additionally, 69 imported lemon juice samples were evaluated using combustion module-cavity ring down spectrometry (CM-CRDS) and compated with the well-established EA-IRMS, Equivalency of CD-CRDS to EA-IRMS was further demonstrated by conductin a round-robin study involving eight laboratories throughout the United States, Canadam and New Zealand. Results: Overall, the results obtained for CM-CRSA were statistically indistinguishable fronm the results obtained using EA-IRMS for EMA lemon juice analysis. Conclusions: Therefore, CM-CRDS is a viable option for the application. Highlights: The CM-CRDS instrumentation is easy to operate, robust, and provides delta-13C values comparable to EA-IRMS for citrate analysis. Through a multi-laboratory exercise, CM-CRDS was shown to be an alternative to EA-IRMS in the detection of economic adulteration of lemon juice.