Sant Joan del Mercat church

The usefulness of this kind of analysis is illustrated in Fig. 2.11 where the square wave voltammograms for azurite, smalt, and two samples from the frescoes painted by Palomino (1707) in the Sant Joan del Mercat church in Valencia (Spain) are shown. Copper pigments yield a unique stripping peak at —0.05 V, whereas cobalt pigments produce a main anodic peak at +0.02 V, accompanied by overlapping... 

Fig. 2.11 Square wave voltammograms for blanks of azurite and smalt, and for two samples from the Palomino s frescoes in the Sant Joan del Mercat church in Valencia, in contact with 0.50 M potassium phosphate buffer, pH 7.4 (a) azurite, (b) sample PV8b, (c) smalt, and (d) sample PA5b. Potential scan initiated at —0.85 mV in the positive direction. Potential step increment 4 mV square wave amplitude 15mV frequency 2Hz [133]...

Fig. 3.3 Image of a portion (area ca. 1 m ) of the damaged Palomino s frescoes in the vault of the Sant Joan del Mercat church in Valencia (Spain) [133]...

Fig. 4.7 Calibration graph for estimating the tenorite/(azurite + smalt) ratio in thermally altered samples from the Sant Joan del Mercat church, using the quotient between the peak currents for voltammetric signals at —0.10 and —0.60 V [133]...

Fig. 4.11 Frequency diagram forthe dosages of azurite + smalt mixtures determined in Palomino s frescoes in the Sant Joan del Mercat church...

Fig. 4.12 Variation of the tenoiite/(azuiite + smalt) (w/w) ratio in samples from the Sant Joan del Mercat church in Valencia, with the angle from the axis in the vault...

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