Interpretation Of Analytical Data Research Articles

Processing and Interpretation of Analytical Data with a High Degree of Uncertainty

Some analytical problems, which are often considered incorrect for objective reasons, are considered. The main of these reasons is an anomalously large scatter of the initial data. It can be due to either the low reproducibility of the characteristics of substances, their quantities, analytical signal intensities, process conditions, etc., or variability due to differences in the nature of the objects themselves. In the latter case, the nature of data interpretation is influenced by analytical hypotheses adopted for their consideration. The tasks considered include variations in the component composition of developers for black-and-white negative photographic materials, comparison of temperature parameters of the gas-chromatographic separation of various organic compounds, toxicity characterization (LD50) of homologues using C3–C12 1-alkanols as an example, and the possibility of predicting sample preparation operations in the determination of drugs in blood plasma based on their physicochemical characteristics. The main features of data interpretation characterized by a high degree of uncertainty are revealed. It is noted that important conclusions can be drawn based on the facts of low reproducibility (one-dimensional arrays) or poor correlation of variables (two-dimensional arrays).

Impact of Anthropic Activities on the Quality of Groundwater in the Central Rif (North Morocco)

The present study aimed to evaluate the effects of human anthropic activities on the physicochemical and biological properties as well as the quantity of the groundwater in the central Rif of Morocco. Series of analyses were carried out on the water resources of this area. The interpretation of analytical data and the distribution of groundwater into groups were treated using multivariate statistical methods including Principal Component Analysis (PCA) and the Ascending Hierarchical Classification (CHA). The results of the present study showed strong mineralization of the investigated area waters. This study also indicated the impact of anthropogenic activities and their influences on the quality of groundwater in the central Rif, with the presence of total coliforms, fecal Escherichia coli type, and fecal streptococci intestinal enterococcal type, suggesting that the contamination of this groundwater was induced by human pollution. In addition, the infiltration of groundwater by wastewater from septic tanks, the use of wastewater for irrigation purposes, the increased use of fertilizers and pesticides in agriculture, and irregular rainfall in the region constitute the main factors of anthropogenic contamination of groundwater in the study area.

Analysis of mordants, driers, and lapis lazuli using x-ray fluorescence: comparative research using reconstructed paint samples and case studies

Changes in the formulation of pigments and paint binders and the presence of additives used in the history of painting can complicate the interpretation of analytical data and may influence the characterization of the materials used in artworks. The limitations of the common analytical tools used to identify potential paint components including metallic driers, pigments, and the inorganic substrates of lake colors may also make analysis more difficult. X-Ray Fluorescence (XRF) spectroscopy is a common non-destructive technique used to collect inorganic elemental information from artworks. Advancements in XRF technology now permit the gathering of data from multi-layered paint systems and scanning technology can help characterize pigments across the entire surface of an artwork. These tools require an even greater understanding of the potential materials in an artwork to avoid misinterpretation of the data. The authors tested XRF’s ability to characterize lead, manganese, and cobalt driers. The presence of metallic driers could have an impact on the interpretation of the inorganic components in paint films. Lake pigment substrates often contain aluminum, tin, and calcium salts. The detection of these ions was also studied. Finally, the XRF detection of aluminum in lapis lazuli samples was assessed. These three groups of materials were also mixed with driers and/or other pigments to determine whether the presence of additional metal ions inhibited the detection of the characteristic elements. The authors used a Bruker ArtTax Micro XRF and a handheld Bruker Tracer III-SD XRF unit with and without a vacuum or helium purge for these experiments.

Groundwater quality assessment in Jirania Block, west district of Tripura, India, using hydrogeochemical fingerprints

A hydrogeochemical assessment was carried out in Jirania Block of west district of Tripura, India, to evaluate the geochemical processes and groundwater suitability for drinking and irrigation purposes. Twenty-two groundwater samples were collected at different lithologies in the study area during post-monsoon period. The collected samples were analyzed for major ions and heavy metals using the standard protocols. The analyzed parameters were used for various geochemical plots and indices to classify the groundwater quality. The order of dominance of cations is Ca2+ > Mg2+ > Na+ > K+ and HCO3− > Cl− > SO42− > NO3− for anions. Higher concentration of Fe and Mn was observed in most of the samples, which are above the acceptable limit of BIS standard. Correlation analysis and factor analysis were applied to unravel the relationship between ions and to identify the possible geochemical processes in groundwater. The interpretation of analytical data, plots and indices reveals that the weathering, mineral dissolution and ion exchange reactions are the major controlling factors for the groundwater geochemistry. The quality of the groundwater is suitable for drinking and irrigation purposes to the local community in this assessment period.

Chemometrics in forensic chemistry — Part I: Implications to the forensic workflow

The forensic literature shows a clear trend towards increasing use of chemometrics (i.e. multivariate analysis and other statistical methods). This can be seen in different disciplines such as drug profiling, arson debris analysis, spectral imaging, glass analysis, age determination, and more. In particular, current chemometric applications cover low-dimensional (e.g. drug impurity profiles) and high-dimensional data (e.g. Infrared and Raman spectra) and are therefore useful in many forensic disciplines. There is a dominant and increasing need in forensic chemistry for reliable and structured processing and interpretation of analytical data. This is especially true when classification (grouping) or profiling (batch comparison) is of interest.Chemometrics can provide additional information in complex crime cases and enhance productivity by improving the processes of data handling and interpretation in various applications. However, the use of chemometrics in everyday work tasks is often considered demanding by forensic scientists and, consequently, they are only reluctantly used. This article and following planned contributions are dedicated to those forensic chemists, interested in applying chemometrics but for any reasons are limited in the proper application of statistical tools — usually made for professionals — or the direct support of statisticians. Without claiming to be comprehensive, the literature reviewed revealed a sufficient overview towards the preferably used data handling and chemometric methods used to answer the forensic question. With this basis, a software tool will be designed (part of the EU project STEFA-G02) and handed out to forensic chemist with all necessary elements of data handling and evaluation.Because practical casework is less and less accompanied from the beginning to the end out of the same hand, more and more interfaces are built in through specialization of individuals. This article presents key influencing elements in the forensic workflow related to the most meaningful chemometric application and evaluation.

A Study of Picasso's Painting Materials and Techniques in Six of His Early Portraits

Six early portraits from 1895 to 1900/1 by Pablo Picasso were comprehensively examined using complementary non-destructive techniques provided by the MOLAB Transnational Access Service as part of the European Cultural Heritage Advanced Research Infrastructures (CHARISMA) project. The paintings were selected by the Museu Picasso, Barcelona, as representative of Picasso's formative years. This paper presents a compendium of the results from the extensive analysis campaign, which involved meticulous inspection of the stratigraphy of each portrait and elucidation of the palette used by the artist in his early career. Subsurface imaging (X-ray radiography and infrared reflectography) was used to guide analytical data interpretation. Prussian blue, cobalt blue, ivory black, lead white, natural earths, vermilion, chromium-based pigments, and different fillers were identified in the paintings. With this simple palette, Picasso was able to play with the colors to create different shades and tones. Careful inspection of the brushstrokes and material distribution highlighted important details, providing a better understanding of the creative process behind the portraits studied and young Picasso's modus operandi. Furthermore, all the portraits were found to have been painted over earlier compositions.

Archaeology and archaeometallurgy: some unresolved areas in the interpretation of analytical data

This paper uses examples from Mediterranean and in particular Italian prehistory to explore the interface between prehistoric archaeology and metals analysis by examining three areas: the usefulness of data from past analyses (‘what is it made of?’), lead isotope analysis and the problem of unpublished data (‘where is it from?’), and the interpretation of analytical data (‘what does it mean?’). Issues discussed include big data, the integration of datasets from different analytical programmes (especially where analytical results are in disagreement), and open access and the withholding of data through incomplete publication, which means that conclusions cannot be verified. It offers some suggestions as to how communication between archaeologists and archaeometallurgists can be improved.

ПРОБЛЕМЫ ЭКОНОМИЧЕСКОГО РАЗВИТИЯ: ФАКТОРЫ И ДЕТЕРМИНАНТЫ

The subject / topic: TThe theme of this article is very relevant in the light of changes in the global geo-economic structure and changing the role and place ofRussiain world economic and geopolitical relations. The article deals with the basic aspects of national economic growth, which slowed down in the last three years. The main reason for slowing national economic growth is associated with the depletion of the reserves of the traditional export-oriented development of the Russian economy, as well as problems with sluggish innovative transformation. In this paper, based on a systematic analysis of economic processes and the interpretation of analytical data, addresses the general theoretical and methodological aspects of the quality of economic development, as well as practical guidelines and recommendations related to sustainable national socio-economic development in the context of external constraints. The purpose / objectives: The aim of the article is to analyze the theoretical and methodological aspects of the quality of economic development of the Russian economy, which happened in the face of economic sanctions. Objectives of the article: justify practical directions and recommendations related to sustainable national socio-economic development in the context of external constraints, determine the prospects for the economy of theRussian Federationin the conditions of the introduction of sectoral sanctions by Western countries. Methodology: Methodological basis of this article are the comparative and economic-statistical methods of analysis. The Results: The study revealed that the harsh environment (sanctions, depreciation of the ruble, and others.) Require surgical intervention and adjustments not only the current socio-economic plans, but also to take urgent measures to ensure the development prospects. The most important decision is the degree of support advanced scientific and technical programs and the creation of new domestic technologies. Conclusions / significance: Measures to ensure the recovery mechanism of reproduction of the development potential of the economy on the basis of innovation should be complemented by a faster action to increase the absorptive capacity for innovation and new technologies. The practical application of the results of this work will improve procedures for forecasting and planning the strategic development of an economic complex in view of the current economic and social trends.

Selected Problems on Ion Chromatography Determinations of Trace Elements in Clinical Samples

The aim of this article is to introduce readers and clarify important issues related to the analysis of trace elements in clinical samples (biological fluids, tissues) using ion chromatography (IC). IC is a convenient analytical method for the analysis of ions in samples also with a complex matrix. However, despite the advances in technology and methodology, it is rather overlooked in the routine analysis of clinical samples. The problems faced by the analyst before and during the analysis of clinical samples and their influence on the interpretation of analytical data are discussed in the following review. Examples of speciation analyses involving IC are also presented. Topics are limited to selected trace elements and all applications described here are taken from published literature. Keywords: Biofluids, blood, certified reference materials, clinical samples, collection, digestion, dilution, ion chromatography, preservation, serum, storage, toxicity, trace elements, urine, validation.

Interpreting Analytical Chemistry Data: Recent Advances in Curve Resolution with the Aid of Chemometrics

This overview summarizes the application and impact of chemometrics on the extraction and interpretation of analytical data with the use of curve resolution methods from about 2005 onward. The development and usage of well-known and novel chemometric methods have been described and approximately 85 papers have been referenced. Many suggested improvements to some well-known methods, for example, multivariate curve resolution, have been noted as well as the growing software for such methods. Also, these high dimensional resolution methods have found significant application and, arguably, have opened up a new perspective in calibration, that is, extraction of otherwise unobtainable analytical information from strongly overlapping profiles in the presence of interferences. Recent literature suggests that the use of chemometric methods in analytical chemistry for data extraction and interpretation provides indispensable tools for multivariate data processing and extraction of hidden information, which otherwise would be difficult to obtain.

Compatibility of the ammonium lactate (AL) and sodium bicarbonate (Olsen) methods for determining available phosphorus in Swedish soils

Plant-available P was first extracted in soils 114 years ago and a number of different analytical methods have since been developed, but for good reasons none of these methods has been adopted as a standard for all soils. With increasing cooperation within research, there is a need to harmonise the interpretation of analytical data for fertiliser recommendations, research, and environmental control. This paper evaluates the compatibility of the Swedish standard ammonium lactate (PAL) method and the widely used Olson's sodium bicarbonate (POls) method in 82 topsoil samples taken from Swedish long-term soil fertility field trials. The PAL-values were usually larger than POls, with a mean PAL/POls quotient of 2.30±1.04 (0.67–6.58). The PAL and POls means and ranges were 126±89 (5–360) and 55.1±33 (3.1–122.8) mg P kg−1 dry soil, respectively. Stepwise multiple linear regression analysis was used to evaluate the relationship between PAL and POls and how this relationship was affected by clay content, pH, and soil organic carbon content (SOC). After statistical transformation, it emerged that the square root of clay content (17.4%±13.82, range 1–54.4) and pH (6.45±0.54, range 5.5–7.7) significantly affected the relationship at partial R 2-values of 2 and 12%, respectively, while ln(SOC) (2.54%±1.21, range 1–6.03) did not, apparently due the narrow range. The regressions of predicted vs. measured values explained 95 and 94% of the variation in PAL and POls, respectively. The mean deviation of predicted compared with measured values was 21.3 and 8.3 mg P kg−1 dry soil for PAL and POls, respectively, corresponding to 20 or 19% of the measured values. We conclude that a data set consisting of PAL-values can be converted into POls-values and vice versa with reasonably high accuracy when accounting for clay content and pH.

DETERMINATION OF MICRO NUTRIENTS IN SUBSTRATES BY WATER EXTRACTION AND INTERPRETATION OF THE ANALYTICAL DATA

In 1974 the 1:1½ volume extract was published (Sonneveld et al., 1974) as a water extraction method for the determination of available nutrient elements and of the salinity status of peaty substrates. The analytical data of this extract were related to the data of the “substrate” solution extracted from the substrates with a moisture condition of -3.2 kPa. The method has been widely used and offers a suitable basis for fertilization of peaty substrates. In the years after publication, the composition and application of substrates has undergone much change and the irrigation methods have also been thoroughly adjusted. The latter was responsible for increased water contents in the substrate during crop growth. Therefore, another study was carried out in which the analytical data of the 1:1½ volume extract was compared with the analytical data of the “substrate” solution, where the “substrate” solution was defined at the moisture condition of -1.0 kPa. There was a good agreement between the results of both studies. However, the regression coefficients for the relationships between the data of the extracts differ, as expected, because of the higher moisture contents on which the substrate solution was defined. In addition to the data of major elements published, in the second study, micro nutrients were determined in the extracts, but not published. Therefore in this paper the relationships between the concentrations of micro nutrient as determined in the 1:1½ extract and in the “substrate” solution are given. The relationships presented support the interpretation of analytical data of micro nutrients by means of water extraction.

Parallel analysis of stimulants in saliva and urine by gas chromatography/mass spectrometry: Perspectives for “in competition” anti-doping analysis

Stimulants are banned by the World Anti-Doping Agency (WADA) if used “in competition”. Being the analysis of stimulants presently carried out on urine samples only, it might be useful, for a better interpretation of analytical data, to discriminate between an early intake of the substance and an administration specifically aimed to improve the sport performance. The purpose of the study was to investigate the differences, in terms of excretion/disappearance of drugs, between urine and oral fluid, a sample that can reflect plasmatic concentrations. Oral fluid and urine samples were collected following oral administration of the following stimulants: modafinil (100 mg), selegiline (10 mg), crotetamide/cropropamide (50 mg each), pentetrazol (100 mg), ephedrine (12 mg), sibutramine (10 mg), mate de coca (a dose containing about 3 mg of cocaine); analysis of drugs/metabolites was carried out by gas chromatography/mass spectrometry (GC/MS) in both body fluids. Our results show that both the absolute concentrations and their variation as a function of time, in urine and in oral fluid, are generally markedly different, being the drugs eliminated from urine much more slowly than from oral fluid. Our results also suggest that the analysis of oral fluid could be used to successfully complement the data obtained from urine for “in competition” anti-doping tests; in all those cases in which the metabolite(s) concentration of a substance in urine is very low and the parent compound is not detected, it is indeed impossible, relying on urinary data only, to discriminate between recent administrations of small doses and remote administrations of higher doses.

ARC: Automated Resource Classifier for agglomerative functional classification of prokaryotic proteins using annotation texts

Functional classification of proteins is central to comparative genomics. The need for algorithms tuned to enable integrative interpretation of analytical data is felt globally. The availability of a general,automated software with built-in flexibility will significantly aid this activity. We have prepared ARC (Automated Resource Classifier), which is an open source software meeting the user requirements of flexibility. The default classification scheme based on keyword match is agglomerative and directs entries into any of the 7 basic non-overlapping functional classes: Cell wall, Cell membrane and Transporters (C), Cell division (D), Information (I), Translocation (L), Metabolism (M), Stress(R), Signal and communication (S) and 2 ancillary classes: Others (O) and Hypothetical (H). The keyword library of ARC was built serially by first drawing keywords from Bacillus subtilis and Escherichia coli K12. In subsequent steps,this library was further enriched by collecting terms from archaeal representative Archaeoglobus fulgidus, Gene Ontology, and Gene Symbols. ARC is 94.04% successful on 6,75,663 annotated proteins from 348 prokaryotes. Three examples are provided to illuminate the current perspectives on mycobacterial physiology and costs of proteins in 333 prokaryotes. ARC is available at http://arc.igib.res.in.

CATION CONCENTRATIONS OF PLANT TISSUES OF FRUIT-VEGETABLE CROPS AS AFFECTED BY THE EC OF THE EXTERNAL NUTRIENT SOLUTION AND BY HUMIDITY

CATION CONCENTRATIONS OF PLANT TISSUES OF FRUIT-VEGETABLE CROPS AS AFFECTED BY THE EC OF THE EXTERNAL NUTRIENT SOLUTION AND BY HUMIDITY

Database use in Forensic Analysis

Databases play an important part in Forensic Science. In terms of X-ray analysis (X-ray powder diffraction), databases include those used for the interpretation of analytical data, and those created from the results of interpretation. The former includes the ICDD Powder Diffraction File (Full file) and its Forensic Subfile. The latter consists of a variety of locally created databases on, for example, paint compositions and drug seizure compositions. These small databases are useful in assessing the evidential value of analytical results, and if populated over a long enough period, can provide other types of information such as manufacturing and social trends.

Qualitative chromatographic-mass spectrometric analysis of highly toxic alkyl phosphonate and alkyl thiophosphonate derivatives

The main goal of chemical analytical monitoring in the destruction of chemical weapons is to identify highly toxic compounds of similar structures in long homologues series. The difficulties with the identification are due to a wide range of possible structures of such compounds with similar mass-spectral patterns. This necessitates the development of special approaches to the interpretation of analytical data. The paper presents the data of experimental studies of specific features of chromatographic–mass spectrometric behavior of 150 substances of the specified classes. The account of these data can improve the reliability of the identification.

Environmetrical interpretation of analytical data of marine organisms from the black sea

The environmetrical analysis of the benthic organisms data set from a Black sea region has revealed new information concerning the chemical content and the bioindicating abilities of polychaeta (Melina palmata), Crustacea (Aspendopsis ostroumovi) and molluscs (Mytilus gallo‐provincialis). The application of various multivariate statistical approaches like cluster and principal component analysis, linear regression and partial least square modeling, source apportioning makes it possible to understand in a better way the properties of the benthic organism as collectors of pollutants in a total and a more specific mode. It is shown that heavily polluted coastal zones are indicated in the same way by all benthic species but some specificity could be detected when moderately polluted zones are considered. In this case polychaeta accumulated preferably Co, Cr, Cu and Pb Crustacea ‐ As, Cd and Ni and molluscs ‐ Zn to a limited extent. PCA identified three latent factors (“anthropogenic flotation”;, “anthropogenic galvanic”; and “naturally occurring") which explain about 65% of the total variance of the system and determine the data set structure. The source apportioning on the absolute principal component scores proved that none of the metals is quantitatively linked with only one anthropogenic or natural source. The linear regression and PLS models have indicated that a reliable prognosis of the pollution on some naturally occurring chemical components (e.g. linear regression on Zn for Cr and Ni) or combination of them (PLS modeling on Mn/Zn or on Mn/Zn/Fe for the rest of the pollutants) could be achieved.

Interpretation of analytical data on n-alkanes and polynuclear aromatic hydrocarbons in Arbacia lixula from the coasts of Tenerife (Canary Islands, Spain) by multivariate data analysis

The hydrocarbons contents (n-alkanes, polycyclic aromatic hydrocarbons) were determined in the sea urchin Arbacia lixula. Multivariate data analysis as principal component analysis, factor analysis and, cluster analysis were applied to elucidate sources of pollution. PCA and FA were performed to establish the relationships between variables (hydrocarbons), samples (sea urchin) and sources of pollution.

Mineralogical analysis as a means for distinguishing levels in a red soil chronosequence

Three red soils and a brown soil developed on the three distinct levels of the fluviglacial terraces in the interfluvial area between the beds of the rivers Aragón and Aragón Subordán (Pyrenean range, France‐Spain) were studied. This terrace system features ubiquitous red soil topping the upper 60 m terrace and brown soil on the intermediate (20 m) and lower terrace (2–3 m). However, the most salient feature of the studied area, an explanation for which was sought in this work, is the presence of red soils in the two sub‐levels that form the 20 m terrace. For this purpose, and also with a view to characterizing the soils, material from the different levels studied was subject to textural analysis using three different dispersal methods (water, Sodium hexametaphosphate, and previous removal of iron oxides). In this way, the clay/silt ratio and naturally dispersed clay (NDClay) were determined (the latter as the clay‐H2O/clay‐hexam ratio). The heavy and light fractions of sand were examined under a petrographic microscope and a scanning electron microscope (SEM) and the results were subjected to an analysis of variance. The interpretation of these results, in addition to the presence of pseudomorphic pyrites and other iron forms, and on the interpretation of analytical data, the red soils in the two sub‐levels of the 20 m terrace were transported from a neighboring zone.