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In this poster we will present some results of a research projects dealing with Arabic recipes of black inks [1-2]. To improve conservation practices of Arabic manuscripts we have assessed the feasibility of the recipes collected from many Arabic sources on bookmaking and reproduced the most common inks. Ink samples were then artificially aged and analysed using an array of analytical techniques, mostly non-invasive, in order to build a database of Arabic inks and their ingredients and also to verify the detection limits of the portable equipment employed.
We will show procedures and problems concerning the identification of ink types and ingredients using reflectography (in Vis, IR and UV), X-Ray Fluorescence, Infrared and Raman spectroscopy. The focus will be in particular on squid ink [3] and mixed inks – both in the form of carbon inks with the addition of tannins and of a mixture of carbon and iron gall inks – which are particularly difficult to detect [4]. We will also examine the results of iron gall inks made with iron filings or nails instead of vitriol, the various precursor used to extract gallic acid that are mentioned in the sources as surrogates of gall nuts.
[1] A. Schopen, Tinten und Tuschen des arabisch-islamischen Mittelalters, Göttingen: Vandenhoeck & Ruprecht, 2004
[2] S. Fani, Le arti del libro secondo le fonti arabe originali. I ricettari arabi per la fabbricazione degli inchiostri (sec. IX-XIII): loro importanza per una corretta valutazione e conservazione del patrimonio manoscritto, PhD thesis, Napoli: Università L’Orientale, 2013
[3] S. Centeno, J. Shamir Journal of Molecular Structure, 873 (2008), 149-159
[4] C. Colini et. al, Manuscript cultures, 11 (2018) 43-50
In this poster we will present some results of a research projects dealing with Arabic recipes of black inks. To improve conservation practices of Arabic manuscripts we have assessed the feasibility of the recipes collected from many Arabic sources on bookmaking and reproduced the most common inks. Ink samples were then artificially aged and analysed using an array of analytical techniques, mostly non-invasive, in order to build a database of Arabic inks and their ingredients and also to verify the detection limits of the portable equipment employed.
First, we will provide an overview of the sources [1-2] employed in the study – dating from 9th to 14th century, although the manuscripts in which they can be found dates up to the 20th century – with an eye on the ink typologies (real and perceived by the compilers). Then we will show how, by reproducing the recipes, it was possible to shed light on some oddities in the procedures and the choice of ingredients. In the end we will discuss problems concerning the identification of ink types and ingredients using reflectography (in Vis, IR and UV), X-Ray Fluorescence, Infrared and Raman spectroscopy. The focus will be in particular on mixed inks – both in the form of carbon inks with the addition of tannins and of a mixture of carbon and iron gall inks – which are particularly difficult to detect [3]. We will also examine the results of iron gall inks made with iron filings or nails instead of vitriol and the various precursor used to extract gallic acid that are mentioned in the sources as surrogates of gall nuts.
[1] A. Schopen, Tinten und Tuschen des arabisch-islamischen Mittelalters, Göttingen: Vandenhoeck & Ruprecht, 2004
[2] S. Fani, Le arti del libro secondo le fonti arabe originali. I ricettari arabi per la fabbricazione degli inchiostri (sec. IX-XIII): loro importanza per una corretta valutazione e conservazione del patrimonio manoscritto, PhD thesis, Napoli: Università L’Orientale, 2013
[3] C. Colini et. al, Manuscript cultures, 11 (2018) 43-50
The full-notch creep test (FNCT) is a common method to evaluate the environmental stress cracking (ESC) behavior of high-density polyethylene (PE-HD) container materials . The test procedure as specified in ISO 16770 provides a comparative measure of the resistance against ESC using the time to failure of specimens mechanically loaded in a well-defined liquid environment. Since the craze-crack damage mechanism underlying the ESC process is associated with brittle failure, the occurrence of globally brittle fracture surfaces is a prerequisite to consider an FNCT measurement as representative for ESC . Therefore, an optical evaluation of FNCT fracture surfaces concerning their brittleness is essential. Due to the experimental setup, an inevitable increase of the true mechanical stress and the associated appearance of small ductile parts on fracture surfaces is induced in any case. Hence, an FNCT experiment is considered as 'valid', if the corresponding fracture surface is predominantly brittle . Based on laser scanning microscopy (LSM) height data of FNCT fracture surfaces , a universal and easy-to-use phenomenological criterion was developed to assess the validity of distinct FNCT experiments. This criterion is supposed to facilitate a quick evaluation of FNCT results in practical routine testing.
Porous materials play an important role in several fields of technology, especially for energy applications like photovoltaics, electrolysis or batteries. The activity of porous films is affected by properties like porosity, film thickness, chemical composition of the material as well as the crystallinity of the framework. The complex morphology of such porous films constitutes a challenge even for modern analytical techniques and requires new approaches employing the combination/complementation of data of different analytical methods. In this contribution we characterize thin mesoporous iridium-titanium mixed oxide film properties by Electron Probe Microanalysis (EPMA) with energy dispersive X-ray spectroscopy (EDS) at an SEM.
Analysis of elemental composition of Fe1-xNix and Si1-xGex alloy thin films by EPMA and µ-XRF
(2019)
The present study reports on measurements on thin Fe-Ni films on silicon and first-time results of analysis on Si-Ge thin films deposited on a non-conductive aluminium oxide Substrate by electron probe microanalysis (EPMA). Standard-based and standardless EPMA (with EDS) results were used in combination with the thin film analysis software Stratagem for the quantification.
Further, X-ray fluorescence analysis (XRF) can be used for the determination of elemental composition and thickness of such films as well. In this case, XRF with a μ-focus X-ray source (μ-XRF) attached to a SEM was applied. For quantification, a fundamental parameter (FP) approach has been used to calculate standard-based and standardless results.
Both thin film systems have been chosen as samples of an international round robin test (RRT) organised in the frame of standardisation technical committee ISO/TC 201 ‘Surface chemical analysis’, under the lead of KRISS. The main objective of the RRT is to compare the results of atomic fractions of Fe1-xNix and Si1-xGex alloy films obtained by different surface Analysis techniques, such as X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), and secondary ion mass spectrometry (SIMS) applied in the depth-profiling operation mode.
Five samples of different atomic fractions of each thin film system, i.e., Fe1-xNix and Si1-xGex, have been grown by ion beam sputter deposition on silicon and Al2O3 wafers, respectively. Reference FeNi and SiGe films with well-known elemental composition and thickness have been also supplied for standard-based analysis. An excellent agreement has been obtained between the atomic fractions determined by EPMA and µ-XRF with the KRISS certified values.
Due to the favorable properties of polymers, their production and thus their input into the environment has increased significantly in recent decades. Currently, FTIR or Raman spectroscopy are mainly applied for the analysis of microplastic particles (MP) in environmental samples. However, these methods have great difficulties in determining metrologically traceable MP values, especially with regard to the limiting values, as preferred in regulation. Therefore, we developed a systematic and fast thermoanalytical method called TED-GC-MS (thermal extraction desorption gas chromatography mass spectrometry), which determines mass contents. Now the current goal is the determination of its process parameters.
This poster illustrates the theoretical requirements for MP analysis (left side) and contrast them with the current state of research (right side).Unexpected practical problems are presented and the relatively new method is discussed concerning the quality requirements of well-established methods such as LC-or GC-MS.
Heating oil storage tanks made of polyethylene grades have been on the market in Germany since the early 1970s. To ensure safety, their replacement is recommended by tank manufacturers after a period of 30 years. Polyethylene is subject to ageing by alteration of the properties during its life cycle. The degree of degradation and the nature of the process mainly depend on the chemical alteration of the polyethylene, the wall thickness of the tank and the environmental conditions. There are no data available on the long-term behaviour of the polyethylene grades, especially after a service life of more than 30 years.
The aim of this investigation was to find a suitable test method to determine the factual degree of damage in comparison to the uncontaminated polyethylene grades. Material data of the used polyethylene grades are available because the BAM was the competent authority for the tests and expert reports for the approval of these tanks until the middle of the 1990s. Therefore, tank sections from the bottom, the shell and the roof of 22 individual storage tanks produced of polyethylene grades A and B have been examined by Melt Flow Rate (MFR) and Attenuated Total Reflectance (ATR). Their service life was in the range between 20 and 41 years.
The MFR measurements of the tank sections showed differences in the values depending on the weight which was used (5 kg or 21.6 kg). An increase of the MFR was determined for the samples of polyethylene grade A, whereas a reduction of the MFR values was measured for most samples of polyethylene grade B. This grade is mainly subject to the internal ageing by cross-linkages, increased degree of branched molecules and loss of the plasticizer.
ATR analysis exhibits an absorption band at 909 cm‒1 predominantly in samples of polyethylene grade A indicating chain scission and concomitantly formed terminal vinyl groups. This absorption band can be used for the characterization of the ageing of the polyethylene grades.
CEQAT-DGHS Interlaboratory tests for method validation and measurement uncertainty determination
(2019)
An explosion in a chemical plant or a fire on a dangerous goods vessel - the reason for such accidents can be numerous. Prevention starts in the laboratory where chemicals are tested for their hazardous properties in order to be able to assess the risks involved in their handling. For this purpose, test methods have been developed and published. They are applied globally nowadays. Safety experts, manufacturers, suppliers, importers, employers or consumers must be able to rely on the validity of safety-related test methods and on correct test results and assessments in the laboratory.
Interlaboratory tests play a decisive role in assessing the reliability of test results. Participation in interlaboratory tests is not only a crucial element of the quality assurance of laboratories; as such it is explicitly recommended in DIN EN ISO/IEC 17025. In addition, interlaboratory tests are also used to develop and validate test methods and can be used for the determination of the measurement uncertainty.
Interlaboratory tests on different test methods have been performed by Bundesanstalt für Materialforschung und –prüfung (BAM) and Physikalisch-Technische Bundesanstalt (PTB) in collaboration with the QuoData GmbH during the last 10 years. Significant differences between the results of the participating laboratories were observed in all interlaboratory tests. The deviations of the test results were not caused only by laboratory faults but also by deficiencies of the test method (see interlaboratory test reports of the CEQAT-DGHS Centre for quality assurance for testing of dangerous goods and hazardous substances: www.ceqat-dghs.bam.de).
In view of the interlaboratory test results the following conclusions can be drawn:
• To avoid any discrepancy on classification and labelling of chemicals it should become state of the art to use validated test methods and the results accompanied by the measurement uncertainty.
• A need for improvement is demonstrated for all examined test methods. Thus, interlaboratory tests shall initially aim at the development, improvement and validation of the test methods (including the determination of the measurement uncertainty) and not on proficiency tests.
• The laboratory management and the practical execution of the tests need to be improved in many laboratories.
• The term "experience of the examiner" must be seen critically: A "long experience with many tests" is not necessarily a guarantee for correct results.