Surface analysis of 24% lead crystal glass articles: Correlation with lead release

The surface of unused lead crystal wine goblets before and after acetic acid extraction tests was analysed with the surface analytical techniques electron probe microanalysis (EPMA), x-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS). The release of lead was determined by 24 h extraction tests with 4% acetic acid at room temperature, preparing the samples in two conditions: unwashed (as received, formed and stored for 6 months) and washed with water. Lead release in the first 5 mins was 50% of the 24 h release. 24 h lead release decreased by about 20% after washing. Pb release from samples exposed to a second or third acetic acid extraction test was a small fraction of the initial one. According to surface analytical techniques, the surface of the unwashed sample shows the presence of easily removable lead, probably accumulated during forming and storage. At least a fraction of this lead is removed during washing justifying the decreased release from the washed sample. 24 h leaching in acetic acid causes a complete dissolution of the surface deposits plus a further lead extraction from the underlying glass. The ensuing lead depletion and silica enrichment justify the moderate release observed under conditions of repeated extraction. Surface analytical results explain the lead leaching behaviour.