The information potential of human skeletal remains—as for any excavated material—is impacted by the conditions of archaeological burial, and the environments and actions experienced during subsequent excavation, laboratory processing, study, and storage. A conservation approach emphasizes the mitigation of threats to material stability and integrity, which for excavated collections are often most critical at the point of archaeological exposure and recovery. Conservation techniques involving application of modern synthetic materials for stabilizing skeletal remains in the field are discussed, using case examples primarily from terrestrial archaeological projects in Mesoamerica. The potential effects of the use of various conservation materials on results of biomolecular instrumental analysis are included.

Introduction. Chlordecone (CLD), an organochlorine formerly used to control the banana black weevil, is strongly adsorbed on soils, particularly on andosols. A simplified analytical procedure for the quantitative determination of chlordecone residues in water and micro-samples of soil and plants was compared with a standard method. Materials and methods. The procedure combines a simplified sampling protocol and a 10-min solid phase microextraction (SPME), followed by gas chromatographic separation (GC) and mass spectrometric (MS and MS/MS) identification. Quantitation of CLD used a standard addition method with zero extrapolation. First, seventy samples were analysed using the proposed method and the standard method based on hot solvent extraction. Second, fifteen soil samples were analysed with two SPME methods followed by GC-MS but using CLD labelled with C13 as an internal standard or the proposed method. Results and discussion. The detection (LOD) and quantitation (LOQ) limits of our SPME extraction procedure were determined for GC-MS and GC-MS/MS with water, plant (pineapple roots) and soil samples: in water for MS/MS, LODMS/MS-water = 0.5 ng×L–1, LOQMS/MS-water = 2.0 ng×L–1; in andosol for MS/MS, LODMS/MS-soil = 15.0 ng×kg–1 dw, LOQMS/MS-soil = 80.0 ng×kg–1 dw. Data from the seventy contaminated soils obtained with the proposed method and the standard method showed a correlation coefficient of r = 0.86. Data obtained by the two SPME/GC-MS quantitation procedures showed a correlation of r = 0.8073. Conclusion. The method proposes a simplified sample preparation and extraction of CLD in water, plant and soil samples, with no solvent manipulation and which is not time-consuming. The LOD and LOQ were similar to those obtained with other currently used methods. The method is reliable and accurate and may be considered as a good tool for research purposes.

Introduction. In recent decades, there has been increased interest in developing natural non-caloric sweeteners, providing sensory properties similar to sucrose. One of the most promising alternatives is the steviol glycosides, high-sweetness compounds extracted from the leaves of Stevia rebaudiana Bertoni. Characteristics and properties. In this review article, the characteristics of this plant are described. According to the relevant literature data, this review provides insight into the major steviol glycosides as well as their main characteristics and properties. Toxicity and legislation. We describe the current situation on the toxicity and the legal framework of the above sweeteners. Extraction techniques. This review describes the techniques developed for extraction and purification, including conventional extraction with water/solvent, ion exchange, enzymatic extraction, supercritical fluid and with a focus on membrane filtration, for its proven advantages in the purification of aqueous extract obtained by leaching of the leaves. Applications. This review also presents various evidence relating to the implementation of steviol glycosides in the food industry, with an emphasis on their use in the formulation of fruit juices. Conclusions. Finally, the future prospects of these natural sweeteners are presented. They highlight the need for research in this area, and the great appeal and commercial potential of such compounds, which should be focused on continuous assessment in relation to issues such as the intensity, persistence of sweetness and the absence of other residual flavors, in order to ensure their acceptance, preference and choice by the general public.