Differences among Epilobium and Hypericum species revealed by four IR spectroscopy modes: transmission, KBr tablet, diffuse reflectance and ATR.

Introduction: Quality control of dried plant material in assessments of suitability of herbal medicinal products is of extreme importance. Commonly used procedures for identification of species are time consuming and expensive. The development of multivariate statistical methods has enabled application of vibrational spectroscopy for establishing plant species membership.

Potentiometric and ³¹P NMR studies on inositol phosphates and their interaction with iron(III) ions.

Potentiometric, conductometric and ³¹P NMR titrations have been applied to study interactions between myo-inositol hexakisphosphate (phytic acid), (±)-myo-inositol 1,2,3,5-tetrakisphosphate and (±)-myo-inositol 1,2,3-trisphosphate with iron(III) ions. Potentiometric and conductometric titrations of myo-inositol phosphates show that addition of iron increases acidity and consumption of hydroxide titrant. By increasing the Fe(III)/InsP(6) ratio (from 0.

Non-destructive characterisation of iron gall ink drawings: not such a galling problem.

Iron gall inks are of extraordinary historical significance considering their widespread use for over a millennium. Due to their corrosiveness, which is a consequence of their acidity and content of transition metals, iron gall inks accelerate the degradation of the writing or drawing support, which in this study is rag paper. Characterisation of acidity (pH) and degree of polymerisation (DP) of cellulose in paper is thus of high interest as it enables the estimation of material stability and assessment of risks associated with its handling.

Material degradomics: on the smell of old books.

We successfully transferred and applied -omics concepts to the study of material degradation, in particular historic paper. The main volatile degradation products of paper, constituting the particular "smell of old books", were determined using headspace analysis after a 24 h predegradation procedure. Using supervised and unsupervised methods of multivariate data analysis, we were able to quantitatively correlate volatile degradation products with properties important for the preservation of historic paper: rosin, lignin and carbonyl group content, degree of polymerization of cellulose, and paper acidity.

Imidazolium-based ionic liquids for the efficient treatment of iron gall inked papers.

Iron gall inks have been known since Roman times, were widely used in the Medieval Age, and became the most used ink in the Renaissance period. They were still officially used by the German Government as recently as 1973. The two main constituents of the ink are tannic acid and ferrous sulfate (vitriol).

Non-Destructive Evaluation of Historical Paper Based on pH Estimation from VOC Emissions.

Volatile organic compounds (VOCs) emitted from materials during degradationcan be a valuable source of information. In this work, the emissions of furfural and aceticacid from cellulose were studied using solid-phase micro-extraction (SPME) incombination with gas chromatography-mass spectrometry. Two sampling techniques wereemployed: static headspace sampling using SPME for 1 h at 40 C after 18-h samplepreparation at 80 C in a closed glass vial, and contact SPME in a stack of paper (or abook).

Nondestructive analysis and dating of historical paper based on IR spectroscopy and chemometric data evaluation.

Sampling restrictions in analysis of cultural heritage materials narrow the choice of appropriate analytical methods considerably. In this work, near- and mid-FT-IR reflectance data were related to paper properties determined with classical analytical methods using partial least-squares. Nondestructive determination of properties, which are of importance for evaluation of the long-term stability of historical paper, i.

Insight into the short-range structure of amorphous iron inositol hexaphosphate as provided by (31)P NMR and Fe X-ray absorption spectroscopy.

Short-range structure and formation of amorphous aggregates of iron inositol hexaphosphate (iron phytate) were studied by broadline solid-state 31P NMR and Fe X-ray absorption spectroscopy. It was shown that bonds P-O-Fe with strong covalent character exist in solid substances. Iron in these substances is octahedrally coordinated by six oxygen atoms and further monodentatly bonded to three or four phosphorus atoms.

Synthesis of myo-inositol 1,2,3-tris- and 1,2,3,5-tetrakis(dihydrogen phosphate)s as a tool for the inhibition of iron-gall-ink corrosion.

Two myo-inositol phosphates, myo-inositol 1,2,3-tris(dihydrogen phosphate) and myo-inositol 1,2,3,5-tetrakis(dihydrogen phosphate), have been synthesised in several steps from myo-inositol (in Chem. Abstr.: d-myo-inositol) in the form of their sodium salts.

Size exclusion chromatography of cellulose in LiCl/N,N-dimethylacetamide.

Size exclusion of cellulose in LiCl/N,N-dimethylacetamide has been used for the past 15 years, yet much of the current research is still devoted to fundamental studies, as many issues regarding column calibration, separation mechanisms and solution behavior have not been resolved yet. The paper reviews practical aspects of sample preparation and it is demonstrated that sample heating and several techniques to aid solvent exchange call for reevaluation. It is further shown that the use of internal standard may introduce minor improvements in repeatability.

Anti- and prooxidative properties of gallic acid in fenton-type systems.

The anti- and prooxidative properties of gallic acid in Fenton-type systems containing H(2)O(2) and Fe(III) were examined in pH 3-10 reaction media and at reaction temperatures of 20-50 degrees C. Although it is a free radical scavenger, gallic acid may exhibit prooxidative properties, as it promotes the production of hydroxyl radicals due to iron chelation. The overall effect is prooxidative if the ratio of the concentrations of gallic acid and Fe(III) in the reaction medium is smaller than 2.

Enthalpic interactions in size exclusion chromatography of pullulan and cellulose in LiCL-N,N-dimethylacetamide.

Enthalpic phenomena were shown to contribute to the size exclusion separation mechanisms during chromatographic analysis of solutions of pullulan and cellulose in LiCl-N,N-dimethylacetamide (LiCl-DMAc) solvent and eluent. The effect of LiCl concentration in the sample solutions and the effect of temperature were of the same order of magnitude for both pullulan and cellulose samples. This led to systematic errors in the determination of mean molecular mass in the range of tens of percent, depending on the chromatographic conditions and on the molecular mass of the analyte.