Rapid Determination of Lead in Gasoline Using Total Reflection X‐Ray Fluorescence Spectroscopy With Paraffin Fixation

In this study, solid paraffin wax was innovatively employed as the solvent to overcome the technical challenges that total‐reflection x‐ray fluorescence spectrometry (TXRF) encounters with highly volatile organic liquids such as gasoline, thereby enabling efficient determination of lead in gasoline. A customized sample‐preparation tool was developed to deposit uniform paraffin–gasoline composite spots—~50 μm thick and 5 mm in diameter—on the carriers, meeting analytical requirements. Characteristic peaks were deconvoluted using the Superbayes optimized fitting algorithm , matrix effects were corrected with yttrium as an internal standard, and lead concentrations were calculated using software‐integrated sensitivity factors. The method achieved a detection limit of 0.02 μg/g for lead and demonstrated good repeatability (RSD < 2%, ). Its excellent agreement with wet‐chemical results confirms the method's reliability and highlights its promise for rapid, accurate determination of lead in gasoline.