Streamlining metal analysis in wine: Matrix purification for simple lead detection by AAS or portable electrochemical sensor

This study presents a streamlined and gentle approach to the preparation of wine samples for lead determination, eliminating the need for concentrated acid digestion. The method relies on a pass-through solid-phase extraction (SPE) cleanup employing a polymeric styrene-divinylbenzene solid sorbent to selectively purify the wine matrix. Lead was quantified using either graphite furnace atomic absorption spectroscopy (AAS) or a portable electrochemical sensor (MetalSens, OliSens, France). Ultraperformance liquid chromatography (UPLC) analysis of phenolic acids and flavonoids confirmed that the purification step effectively removes most organic interferences without compromising lead detection, with recovery rates ranging from 94 to 101 %. This proposed matrix cleanup minimizes fouling of the pyrolytic AAS platform, enables reliable reuse of SPE cartridges for up to five cycles, and facilitates rapid and accurate electrochemical lead determination in wine, with deviations within 15 % of reference AAS measurements.