Project implementation
An overview of the activities required to meet the project goals
A1.1 | Project initiation: necessary resources and acquisition procedures |
A1.2 | Upgrade and testing of the new experimental LIF set-up |
A1.3 | Optimization of the upgraded LIF experimental set-up |
A1.4 | Design and development of the new LIF software interface |
A1.5 | Design and development of the LIF database |
A2.1 | Optimization of the new LIF software interface |
A2.2 | Preparation of reference samples and demonstrative replicas. Data collection |
A2.3 | Development of an enhanced FTIR method using micro-extraction protocol |
A2.4 | Testing and evaluation of the new analytical methodology on laboratory samples |
A2.5 | Testing and evaluation of the new analytical methodology on real samples |
| Upgraded experimental LIF set-up |
| LIF database of organic compounds |
| Enhanced FTIR method |
| Patent proposal |
| ISI paper (x2) |
| Conference presentation (x2) |
| Annual project report (x2) |
| Final report of the project |
The use of only one excitation wavelength limits the discrimination capabilities of the LIF technique; by using various excitation wavelengths the range of materials than can be detected significantly increases. To this aim a new laser source will be incorporated and a new software interface will be designed in order to increase the performances in terms of data acquisition speed and data processing.
Specific objectives
To facilitate laboratory and field LIF analysis a spectral library of organic compounds will be developed. A variety of model samples (mock-ups) will be created using a wide range of known binders (lipids, proteins, resins, waxes). The spectral library will facilitate remote sensing for identifying and mapping organic compounds in real archaeological samples.
A sample pretreatment using solvent extraction will be developed in order to overcome spectral interferences and thus discriminate overlapping signals and achieve a signal enhancement of superposed compounds. Developed protocol will be tested on laboratory samples (of known composition) and on real samples.
The new proposed method will be tested on laboratory samples (of known composition) and on real archaeological samples (several 2nd century Roman wall painting fragments). The method will be evaluated in terms of: specificity/selectivity, limit of detection, precision and accuracy (under within laboratory repeatability and/or within laboratory reproducibility conditions).
Stage 1
The first stage of the project will include a number of five activities. The main objectives of this phase will be the upgrade of the LIF system (O1) and the development of a LIF spectral library of organic compounds (O2).
Within the first activity (A1.1) we will establish the necessary resources and start the equipment acquisition process. A new laser source will be purchased, along several other mechanical and optical components. The next two activities (A1.2-A1.3) will be focused on the upgrade, testing and optimization of the experimental LIF set-up. The new laser source will be incorporated within the existing LIF system, followed by careful calibration, testing and analysis of all components. A measurement protocol will be established for the LIF fluorescence measurements in order to achieve a good detecting efficiency and high spatial resolution even in the very broad spectral range of radiation emitted upon laser excitation at 266 nm. LIF acquisitions will be optimized for each specific wavelength range. The upgraded LIF system will be tested on reference samples (reference paint samples of known composition that already exist within our laboratory), with a focus on organic materials. The capability to obtain accurate 2-dimensional maps indicative of the distribution of fluorescent organic media will also be tested; imaging capabilities will be further optimized within the second phase of the project.
In order to increase the performances in terms of data acquisition speed and data processing a new user-friendly interface will be designed and developed (A1.4). This new software interface, custom made, will be created together with a specialized software development company (third-party services costs). The last activity of this first phase of the project will be focused on the design and development of a LIF spectral library of organic compounds (A1.5) that will facilitate remote identification and mapping of organic compounds in real samples. Database design, structure and functionality will be established, and then implemented within the main software interface of the LIF system. Design of the reference paint samples and mock-ups that will be analyzed and incorporated (in the second phase of the project) within the LIF database will also be carried. The most important results obtained by the end of this first phase of the project will be disseminated in a scientific ISI paper (Q1/Q2 rank journal).
Stage 2
The second phase of the project will include a number of five activities. The main objectives of this phase will be the development of an enhanced FTIR method using micro-extraction protocol (O3) and testing and evaluation of the new combined method (LIF/FTIR) for in-situ identification and real-time mapping of organic components in real samples (ancient wall paintings) (O4).
The first activity (A2.1) within this stage of the project will be focused on the performance optimization of the new LIF software interface (optimization of algorithms and data structures). The LIF database will be populated (A2.2) with data measurements registered on a large variety of reference samples and demonstrative replicas (around 100 samples). For reference sample preparation various organic binders will be used (oil, egg, milk, animal glue, casein, gum Arabic, wax) alone or mixed in various combinations. Demonstrative samples will combine various pigments (up to five types of pigments) and binders (already mentioned above); in designing the samples several research topics will be considered: mixture analysis, pigment-binder ratio, chromatic overlaps, execution technique (sequence of application of the paint layers).
A refined FTIR method using micro-extraction protocol will be developed and tested (A2.3) on laboratory samples (with low binder-to-pigment ratio) with the aim to achieve a signal enhancement of the absorption bands of the organic compounds. In the final stage of the project the new analytical (LIF/FTIR) methodology will be tested and evaluated on both laboratory samples and archaeological samples. For laboratory samples, the two step-approach method will be evaluated in terms of: sensitivity (level of information obtained: presence, type and nature of the organic compounds), limit of detection, precision and accuracy. For real samples the evaluation of the method will be based on the level of information obtained (sensitivity) and the correlation factor (accuracy) for the level of information obtained. The most important results obtained within this second phase of the project will be presented at international conferences and a scientific ISI paper (Q1/Q2 rank journal) will be published. A patent proposal (New method for in-situ identification and real-time mapping of organic components in ancient wall paintings) will be submitted by the end of the project.