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New approach to the differentiation of marble samples using thermal analysis and chemometrics in order to identify provenance.

Gatta T, Gregori E, Marini F, Tomassetti M, Visco G, Campanella L - Chem Cent J (2014)

Bottom Line: The main data thus obtained after subsequent chemometric evaluation (using Principal Components Analysis) have already proved useful in the identification the original quarry of a small number of archaeological marble finds.One of the most evident advantages of the thermoanalytical - chemometric approach adopted seems to be that it allows the certain identification of an unknown find composed of a marble known to be present among the reference samples considered, that is, contained in the reference file.On the other hand with equal certainty it prevents the occurrence of erroneous or highly uncertain identification if the find being tested does not belong to the reference file considered.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Chemistry, University of Rome "La Sapienza", P.le. Aldo Moro 5, I-00185 Rome, Italy.

ABSTRACT

Background: The possibility of applying a novel chemometric approach which could allow the differentiation of marble samples, all from different quarries located in the Mediterranean basin and frequently used in ancient times for artistic purposes, was investigated. By suggesting tentative or allowing to rule out unlikely attributions, this kind of differentiation could, indeed, be of valuable support to restorers and other professionals in the field of cultural heritage. EXPERIMENTAL DATA WERE OBTAINED ONLY USING THERMAL ANALYTICAL TECHNIQUES: Thermogravimetry (TG), Derivative Thermogravimetry (DTG) and Differential Thermal Analysis (DTA).

Results: The extraction of kinetic parameters from the curves obtained using these thermal analytical techniques allowed Activation Energy values to be evaluated together with the logarithm of the Arrhenius pre-exponential factor of the main TG-DTG process. The main data thus obtained after subsequent chemometric evaluation (using Principal Components Analysis) have already proved useful in the identification the original quarry of a small number of archaeological marble finds.

Conclusion: One of the most evident advantages of the thermoanalytical - chemometric approach adopted seems to be that it allows the certain identification of an unknown find composed of a marble known to be present among the reference samples considered, that is, contained in the reference file. On the other hand with equal certainty it prevents the occurrence of erroneous or highly uncertain identification if the find being tested does not belong to the reference file considered.

No MeSH data available.


Principal component analysis on the data reported in Table1: Scores plot. Legend: ● reference samples; (red diamond) unknown samples.
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Figure 2: Principal component analysis on the data reported in Table1: Scores plot. Legend: ● reference samples; (red diamond) unknown samples.

Mentions: To investigate the relations and the similarities among the different marbles, principal component analysis [20] was applied to all the data reported in Table 1 after autoscaling (excluding of course those in the “1st Tpeak” column, which could not be used as no value is included in this column which corresponds to the cases in which this step was not highlighted). Two components explaining about 80% of the original variance were retained as significant, as estimated by cross-validation [35]. The projection of the scores of the known marbles onto the space of the two significant components is reported in Figure 2.It is evident from the figure that most of the samples of known origin fall relatively close to one another in the scores plot, which suggests that they have similar characteristics. Indeed, the marbles which appear to differ more substantially from the rest are Pentelic, Thassos and Statuario Calocara. Inspection of the loadings for the two PCs (see Figure 3) provides an interpretation of these observed differences. In particular, Thassos and Pentelic appear to have a higher mass loss corresponding to the 1st peak and a lower residue at 1000°C, while Statuario Calocara has a higher activation energy.


New approach to the differentiation of marble samples using thermal analysis and chemometrics in order to identify provenance.

Gatta T, Gregori E, Marini F, Tomassetti M, Visco G, Campanella L - Chem Cent J (2014)

Principal component analysis on the data reported in Table1: Scores plot. Legend: ● reference samples; (red diamond) unknown samples.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4061118&req=5

Figure 2: Principal component analysis on the data reported in Table1: Scores plot. Legend: ● reference samples; (red diamond) unknown samples.
Mentions: To investigate the relations and the similarities among the different marbles, principal component analysis [20] was applied to all the data reported in Table 1 after autoscaling (excluding of course those in the “1st Tpeak” column, which could not be used as no value is included in this column which corresponds to the cases in which this step was not highlighted). Two components explaining about 80% of the original variance were retained as significant, as estimated by cross-validation [35]. The projection of the scores of the known marbles onto the space of the two significant components is reported in Figure 2.It is evident from the figure that most of the samples of known origin fall relatively close to one another in the scores plot, which suggests that they have similar characteristics. Indeed, the marbles which appear to differ more substantially from the rest are Pentelic, Thassos and Statuario Calocara. Inspection of the loadings for the two PCs (see Figure 3) provides an interpretation of these observed differences. In particular, Thassos and Pentelic appear to have a higher mass loss corresponding to the 1st peak and a lower residue at 1000°C, while Statuario Calocara has a higher activation energy.

Bottom Line: The main data thus obtained after subsequent chemometric evaluation (using Principal Components Analysis) have already proved useful in the identification the original quarry of a small number of archaeological marble finds.One of the most evident advantages of the thermoanalytical - chemometric approach adopted seems to be that it allows the certain identification of an unknown find composed of a marble known to be present among the reference samples considered, that is, contained in the reference file.On the other hand with equal certainty it prevents the occurrence of erroneous or highly uncertain identification if the find being tested does not belong to the reference file considered.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Chemistry, University of Rome "La Sapienza", P.le. Aldo Moro 5, I-00185 Rome, Italy.

ABSTRACT

Background: The possibility of applying a novel chemometric approach which could allow the differentiation of marble samples, all from different quarries located in the Mediterranean basin and frequently used in ancient times for artistic purposes, was investigated. By suggesting tentative or allowing to rule out unlikely attributions, this kind of differentiation could, indeed, be of valuable support to restorers and other professionals in the field of cultural heritage. EXPERIMENTAL DATA WERE OBTAINED ONLY USING THERMAL ANALYTICAL TECHNIQUES: Thermogravimetry (TG), Derivative Thermogravimetry (DTG) and Differential Thermal Analysis (DTA).

Results: The extraction of kinetic parameters from the curves obtained using these thermal analytical techniques allowed Activation Energy values to be evaluated together with the logarithm of the Arrhenius pre-exponential factor of the main TG-DTG process. The main data thus obtained after subsequent chemometric evaluation (using Principal Components Analysis) have already proved useful in the identification the original quarry of a small number of archaeological marble finds.

Conclusion: One of the most evident advantages of the thermoanalytical - chemometric approach adopted seems to be that it allows the certain identification of an unknown find composed of a marble known to be present among the reference samples considered, that is, contained in the reference file. On the other hand with equal certainty it prevents the occurrence of erroneous or highly uncertain identification if the find being tested does not belong to the reference file considered.

No MeSH data available.