Figure 3

Time course of metals released from brass alloys. Migration tests of brasses M57 (Pb 0.1-0.2%), Z45 (Pb 1.7-2.2%) and Z33 (Pb 3.1-3.5%) were carried out for 8 hours in synthetic saliva medium with stomach Mucin specie at pH 7.2, 37°C and with 60 rpm agitation rate. Results of copper, lead and zinc measurements at time 0, 1, 2, 4 and 8 hours of incubation are represented in black circles for M57, white circles for Z45 and white triangles for Z33. Linear (zero order) or first order kinetic fits for each set of data are represented in dashed lines for M57, solid lines for Z45 and dotted lines for Z33. Linear regression for lead release, reported slope values of 0.043 ± 0.006, 0.175 ± 0.035 and 0.243 ± 0.051 μg/hcm² for alloys M57, Z45 and Z33, respectively. Bottom right plot, presents the positive correlation between metal release in μg/hcm² and lead content (% w/w) in the brass samples; dashed line corresponds to the linear regression through the origin, resulting in a slope of 0.08 μg/hcm² %Pb (r² = 0.92).