Use of chemometric and geostatistical methods to evaluate pesticide pollution in the irrigation and drainage channels of the Ebro river delta during the rice-growing season

Data sets obtained from quantitative analysis of seventeen pesticides in water samples from a network of irrigation and drainage channels in the Ebro river delta (Catalonia, NE Spain) have been analysed by chemometric and geostatistical methods. Samples were taken at fourteen locations during the main rice-growing season, from May to August 2005. Principal-component analysis enabled investigation of the spatial and temporal distribution of the main pollution patterns caused by application of pesticides in the region under study. A first pesticide-contamination pattern from the Ebro river was differentiated from a second more specific pattern from the water-drainage channels of the delta, collected from the rice fields. The seasonal peak in this more specific rice pesticide source was observed in July. Coupling the results from chemometric data analysis with use of geostatistical methods was shown to be a useful procedure for discovery of the most significant spatial and monthly variations of the main pesticide-contamination patterns, taking into account the particular geographical structure of the area under study.     

Identification of the regulatory proteins in human pancreatic cancers treated with Trichostatin A by 2D-PAGE maps and multivariate statistical analysis

In this paper, principal component analysis (PCA) is applied to a spot quantity dataset comprising 435 spots detected in 18 samples belonging to two different cell lines (Paca44 and T3M4) of control (untreated) and drug-treated pancreatic ductal carcinoma cells. The aim of the study was the identification of the differences occurring between the proteomic patterns of the two investigated cell lines and the evaluation of the effect of the drug Trichostatin A on the protein content of the cells. PCA turned out to be a successful tool for the identification of the classes of samples present in the dataset. Moreover, the loadings analysis allowed the identification of the differentially expressed spots, which characterise each group of samples. The treatment of both the cell lines with Trichostatin A therefore showed an appreciable effect on the proteomic pattern of the treated samples. Identification of some of the most relevant spots was also performed by mass spectrometry.     

Application of near infrared spectroscopy (NIR), X-ray fluorescence (XRF) and chemometrics to the differentiation of marmora samples from the Mediterranean basin

Abstract

Near-infrared (NIR) and X-ray fluorescence spectra were recorded for 15 different samples of marmora, from the Mediterranean Basin and of different colours. After appropriate pretreatment (SNV transform + second derivative), the results were subjected to principal component analysis (PCA) treatment with a view to differentiating them. The observed differences among the samples were chemically interpreted by highlighting the NIR wavelengths and minerals, respectively, contributing the most to the PCA models. Moreover, a mid-level data fusion protocol allowed integrating the information from the different techniques and, in particular, to correctly identify (based on the distance in the score space) three test samples of known type. Moreover, it should be stressed that positive results on the differentiation and identification of marmora were obtained using two completely non-invasive, non-destructive and relatively inexpensive techniques, which can also be used in situ.     

Assessment of priority pesticides,degradation products,and pesticide adjuvants in groundwaters and top soils from agricultural areas of the Ebro river basin

Gas chromatography-mass spectrometry (GC/MS) was employed for the determination of 30 widely used pesticides including various transformation products and alkylphenols in water and agricultural soils with the aim of assessing the impact of these compounds in agricultural soils and the underlying aquifer. The extraction, clean-up, and analytical procedures were optimized for both water and soil samples to provide a highly robust method capable of determining target analytes at the ppb–ppt level with high precision. For water samples, different solid-phase extraction cartridges and conditions were optimized; similarly, pressurized liquid extraction conditions were tested to provide interference-free extracts and high sensitivity. Instrumental LODs of 3–4 pg were obtained. The multi-residue extraction procedures were applied to the analysis of groundwaters and agricultural soils from the Ebro river basin (NE Spain). Most ubiquitous herbicides detected were triazines but some acetanilides and organophosphorus pesticides were also found; the pesticide additive tributylphosphate was found in all water samples. Levels varied between 0.57 and 5.37 μg/L in groundwater, whereas nonylphenol was the sole compound detected in soil. Alkylphenols are used as adjuvants in pesticide formulations and are present in sludges employed as soil fertilizers. Occurrence was found to be similar to other environmental studies.     

Determination and assessment of the contents of essential and potentially toxic elements in Ayurvedic medicine formulations by inductively coupled plasma-optical emission spectrometry

Traditional Ayurvedic remedies are easily available nowadays not only in India, their country of origin, but also in Western countries. Some of these products contain high concentrations of potentially toxic elements as main or secondary ingredients, in addition to elements essential for human health; for these reasons, it is interesting to determine their elemental composition. In this study we assessed the concentrations of fifteen elements (Al, As, Ca, Cd, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Pb, Si and Zn) in five products of the Parpati family, a group of Ayurvedic medicines containing high concentrations of mercury, manufactured in various places in India. Concentrations were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES) or (for Pb and Cd) by graphite furnace atomic absorption spectrometry (GF-AAS) after sample mineralization. We compared the calculated daily intake of each element with reference values, considering maximum tolerable intake levels or recommended nutrient amounts. The experimental results were treated with chemometric pattern recognition techniques. We found differences in the composition of products of the same denomination manufactured by different companies and strong correlations among groups of variables. As expected, the daily intake of mercury upon consumption of Parpati medicines largely exceeded the tolerable intake level of this element.     

Identification of the contamination source of plutonium in environmental samples with isotopic ratios determined by inductively coupled plasma mass spectrometry and alpha-spectrometry

Concentrations of^239+249Pu in environmental samples were detemined by ICP-MS and spectrometry, showing consistent results, which suggests an applicability of ICP-MS to²³⁹Pu and²⁴⁰Pu measurement. The activity ratios of²³⁸Pu/^239+240Pu and²⁴⁰Pu/²³⁹Pu were significantly different in samples from the general environment and near Sellafield reprocessing plants, indicating the usefulness of these ratios for identification of the Pu contamination source.     

Assay of 44 compounds in the cortex and xylem from roots and branches of Ginkgo biloba L. by ultra high performance liquid chromatography coupled with tandem mass spectrometry and chemometric analysis

The leaves of Ginkgo biloba L. have received much attention, whereas there has been little systematic analysis of the cortex and xylem from roots and branches. A comprehensive evaluation of the 44 compounds in the cortex and xylem would thus be of value to fully understand the potential medicinal properties of roots and branches. An assay of amino acids, terpene lactones, flavones, and phenolic acids was accomplished using ultra high performance liquid chromatography with tandem mass spectrometry. All of the calibration curves showed good linear regression (R² > 0.9902) within the tested ranges. The intra‐ and interday precision was less than 4.9% and the accuracy was within ±6.8%. The amount of terpene lactones in the cortex was 1.75–2.07‐fold higher than that in the leaves. The amount of glutamine (360 μg/g) in the taproot xylem was 2.64‐fold higher than that in the leaves (136 μg/g). Principal component analysis decreased in the order leaves > taproot cortex > rootlet > laterals cortex > branch cortex > stem cortex > taproot xylem > branch xylem > laterals xylem > stem xylem. The taproot of G. biloba might provide a supplementary source of terpene lactones, especially ginkgolide A and C, and of glutamine.     

Activities of idol immersion leads to heavy metal contamination in river Hooghly in and around the city of Kolkata

West Bengal is a rich cultural state for a number of religious festivals. One of the most important festival is Kali Puja and Diwali. Idol is supposed to be the image of God which is used for worship. After worshiping immersion of idols took place in the various Ghats of the river. Several accessories of worship such as flowers, food offerings, plastic sheets, polythene bags etc. are also poured in water. Materials of idols consist of clay, plaster of Paris, varnish, oil paint etc. These paints are highly pigmented and consist of white lead, lithopone, chrome yellow, cadmium sulphide, barium chromate, vermillion, red lead etc. heavy metal salts. This study is an attempt to assess the change in water quality before and after the immersion of idols giving emphasis on heavy metal. The above investigation were carried out by collecting the water samples from six immersion ghats of the river Hooghly before & after immersion of Kali idols of the year 2019 followed by the analysis of the different parameters of water. Investigation reveals a significant changes in heavy metal concentration between pre and post immersion of the idols. A pollution due to the idols immersion into the water bodies cause adverse effect to the aquatic life or entire ecosystem.Use of natural dyes for idols obtained from flowers, leaves roots of plants, wood, seeds may reduce this pollution to a significant level. Moreover, awareness among the people of the society may have a significant responsibility in controlling this pollution satisfactorily.     

Determination of pharmaceuticals in river water by column switching of large sample volumes and liquid chromatography–diode array detection,assisted by chemometrics: An integrated approach to green analytical methodologies

An analytical method for the simultaneous determination of nine β-blockers (sotalol atenolol, nadolol, pindolol, metoprolol, timolol, bisoprolol, propanolol and betaxolol) and two analgesics (paracetamol and phenazone) in river water by liquid chromatography and diode array detection is reported. The method involves a modified precolumn switching methodology replacing the small precolumn with a short C18 liquid chromatography column (50 mm × 4.6 mm, 5 μm particle size), thus allowing the preconcentration of large water sample volumes whereas interferences eluting at the first of the chromatogram were discarded to waste. This approach allowed to preconcentrate 30 mL river water samples, modified with 0.4% MeOH, achieving univariate method detection and determination limits ranged between 0.03 and 0.16 μg L⁻¹ and between 0.2 and 0.5 μg L⁻¹, respectively, with precision values lower than 9.4% for spiking levels at the quantitation limits of each analyte and lower than 4.0%, except bisoprolol (8.3%), for higher spiking levels (1.0 μg L⁻¹ of all analytes). Matrix background was reduced in three way data by a baseline correction following the Eilers methodology, whereas multivariate curve resolution and alternating least squares in combination with the standard addition calibration method, applied to these data, coped with overlapping peak, systematic (additive) and proportional (matrix effect) errors. The method was successfully applied for the determination of the target pharmaceuticals in river water from three places in a river stream with acceptable recoveries and precision values, taking into account the complexity of the analytical problem. The joint statistical test for the slope and the intercept of the linear regression between the nominal concentration values versus those predicted, showed that the region computed contained the theoretically expected values (0) for the intercept and (1) for the slope (at a confidence level of 95%), which indicates the absence of both constant and proportional errors in the predicted concentrations.     

Application of chemometric methods to the investigation of main microcontaminant sources of endocrine disruptors in coastal and harbour waters and sediments

Identification, resolution and distribution of main microcontaminant sources of endocrine disruptors in Spanish harbours, coastal waters and sediments are investigated using chemometric methods. We investigated eighteen different endocrine disruptor chemical compounds, including non-ionic surfactants, their degradation products and linear alkylbenzene sulfonates, found in a total number of 74 samples (35 water samples and 39 sediment samples) over a period of 16 months from March 1999 to July 2000, and in 32 different geographical sites along the Spanish Mediterranean Coast (e.g. Barcelona, Tarragona, Almeria Harbour, Malaga and the Bay of Cadiz). Main environmental contamination sources of these endocrine disruptor compounds were investigated and interpreted according to their chemical composition and according to their resolved geographical distribution profiles.An erratum to this article can be found at     

Multivariate analysis of the volatile components in tobacco based on infrared‐assisted extraction coupled to headspace solid‐phase microextraction and gas chromatography‐mass spectrometry

A novel infrared‐assisted extraction coupled to headspace solid‐phase microextraction followed by gas chromatography with mass spectrometry method has been developed for the rapid determination of the volatile components in tobacco. The optimal extraction conditions for maximizing the extraction efficiency were as follows: 65 μm polydimethylsiloxane‐divinylbenzene fiber, extraction time of 20 min, infrared power of 175 W, and distance between the infrared lamp and the headspace vial of 2 cm. Under the optimum conditions, 50 components were found to exist in all ten tobacco samples from different geographical origins. Compared with conventional water‐bath heating and nonheating extraction methods, the extraction efficiency of infrared‐assisted extraction was greatly improved. Furthermore, multivariate analysis including principal component analysis, hierarchical cluster analysis, and similarity analysis were performed to evaluate the chemical information of these samples and divided them into three classifications, including rich, moderate, and fresh flavors. The above‐mentioned classification results were consistent with the sensory evaluation, which was pivotal and meaningful for tobacco discrimination. As a simple, fast, cost‐effective, and highly efficient method, the infrared‐assisted extraction coupled to headspace solid‐phase microextraction technique is powerful and promising for distinguishing the geographical origins of the tobacco samples coupled to suitable chemometrics.     

Interdiffusion/reaction at the polymer/polymer interface in multilayer systems probed by linear viscoelasticity coupled to FTIR and NMR measurements

This paper describes the experimental investigation of the interdiffusion/reaction mechanisms of asymmetric polymer-polymer interfaces. The study deals with the assessment of the chemical reactions occurring at the interface between two reactive polymers. A focal point of the investigation was to study these interfacial reactions by an array of techniques at very different space scales: from macroscopic viscoelastic investigations to IR and NMR spectroscopies at the molecular scale. The studied material pairs include PE-GMA/PA6 as the reactive system (RS) and PE/PA6 as the non-reactive one (NRS) - of coextruded multilayer polymers, i.e., after processing. The linear viscoelastic properties of the reactive multilayer systems were determined and the mechanisms were analyzed by NMR and FTIR measurements. Substantial reactions occurred during the rheological measurements and the results indicated the preferential formation of a copolymer at the interface, triggered by the neighboring layers. Moreover, the contribution of an interface/interphase effect was investigated along with the increase in the number of layers. The results showed that the variation in dynamic modulus of the multilayer system was a result of both diffusion and chemical reaction. Specific experiments were carried out to follow-up on the physicochemical phenomena, and the results were rationalized by comparing the obtained data with theoretical models. The effect of this interphase was quantified at a specific welding time and oscillation frequency thanks to rheological modeling. Because of the coupling between rheology and spectroscopical tools, potential reactions between the GMA functions and the amine/carboxylic polyamide chain ends were explored. The results highlighted that the main reaction mechanism was constituted by the crosslinking reaction between the GMA and carboxylic acid units, and not by that between GMA and amine end functions.     

A spectrophotometric method to determine the siderophore production by strains of fluorescent Pseudomonas in the presence of copper and iron

A simple procedure to determine levels of siderophore production by strains of Pseudomonas, particularly the Avm strain is described. Bacterial cells were incubated for 24 h in iron-rich (RM) and iron-limiting conditions (RM-Fe) with and without 6 and 60 μM of CuSO₄. Cells grown under iron-limiting conditions developed a green color even in the presence of Cu. The spent media supernatants from the Avm cells grown in RM-Fe medium showed a maximum peak of absorbance at 400 nm, which suggest that this strain produced a single type of siderophore. The presence of 60 μM of CuSO₄ in the cultures did not interfere with the detection of siderophores in the spent media. Clear supernatants obtained from cultures of 10 fluorescent Pseudomonas were diluted 1 to 10 in deionized water and the absorption at 400 nm was determined. The results demonstrated the clear discriminating capacity of this highly practical procedure to categorize a great number of fluorescent Pseudomonas strains by the range of siderophore production.     

Use of radiation sources with mercury isotopes for real-time highly sensitive and selective benzene determination in air and natural gas by differential absorption spectrometry with the direct Zeeman effect

A new analytical portable system is proposed for the direct determination of benzene vapor in the ambient air and natural gas, using differential absorption spectrometry with the direct Zeeman effect and innovative radiation sources: capillary mercury lamps with different isotopic compositions (¹⁹⁶Hg, ¹⁹⁸Hg, ²⁰²Hg, ²⁰⁴Hg, and natural isotopic mixture). Resonance emission of mercury at a wavelength of 254 nm is used as probing radiation. The differential cross section of benzene absorption in dependence on wavelength is determined by scanning of magnetic field. It is found that the sensitivity of benzene detection is enhanced three times using lamp with the mercury isotope ²⁰⁴Hg in comparison with lamp, filled with the natural isotopic mixture. It is experimentally demonstrated that, when benzene content is measured at the Occupational Exposure Limit (3.2 mg/m³ for benzene) level, the interference from SO₂, NO₂, O₃, H₂S and toluene can be neglected if concentration of these gases does not exceed corresponding Occupational Exposure Limits. To exclude the mercury effect, filters that absorb mercury and let benzene pass in the gas duct are proposed. Basing on the results of our study, a portable spectrometer is designed with a multipath cell of 960 cm total path length and detection limit 0.5 mg/m³ at 1 s averaging and 0.1 mg/m³ at 30 s averaging. The applications of the designed spectrometer to measuring the benzene concentration in the atmospheric air from a moving vehicle and in natural gas are exemplified.     

Heterogeneous distribution of radiocesium in aerosols, soil and particulate matters emitted by the Fukushima Daiichi Nuclear Power Plant accident: retention of micro-scale heterogeneity during the migration of radiocesium from the air into ground and river systems

We analyzed ¹³⁷Cs in aerosols, rock, soil and river suspended sediment collected after the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. Based on the results, we discuss the post-event behavior and transportation of radiocesium in the environment from the air into ground and river systems. First, radionuclides were emitted from the FDNPP as airborne ‘hot’ particles, which contained water-soluble fractions of radiocesium. Radiocesium was still present in a water-soluble fraction after deposition on the ground. Subsequent interaction of the ‘hot’ particles with water (e.g. rainfall) dissolved and strongly fixed the radiocesium on rock and soil particles, thus changing the radiocesium into insoluble forms. The distribution of ‘hot spots’ was possibly controlled by the initial position of deposition on the ground. Consequently, ‘hot spots’ were studded on the rock surface rather than being uniformly distributed. The distribution of radiocesium in river suspended particles was not homogeneous during water transportation, reflecting the heterogeneity of radiocesium in rock and soil. Leaching experiments demonstrated that radiocesium in rock, soil and river suspended sediment was fairly insoluble, showing that the adsorption reaction is irreversible. The micro-scale heterogeneous distribution of radiocesium in aerosols, soil and suspended particles was due to the presence of ‘hot’ particles in aerosols. Dissolution of radiocesium in the ‘hot’ particles in the aerosols and subsequent irreversible adsorption onto the soil particle complex are responsible for the preservation of the heterogeneity both in soil and in river suspended particles.     

Alternating current anodic stripping voltammetry in the study of cadmium complexation by a reference Suwannee river fulvic acid: a model case with strong electrode adsorption and weak binding

The possibilities of anodic stripping voltammetry (ASV) using an alternating current (AC) scan in the stripping step have been checked through the study of the complexation of cadmium by Suwannee river fulvic acid (SRFA), a reference fulvic acid from the International Humic Substances Society. Because of the strong electrode adsorption of SRFA, AC mode appears to be a good approach to the study when proper selection of the phase angle is made. The goodness of AC mode in ASV has been demonstrated, and the complexation constant of 3.71 ± 0.04 determined is in good agreement with the value of the constant obtained by the reference technique of reverse pulse polarography. Some particularities of SRFA have been observed, among them its homofunctional and strongly heterogeneous behaviour in cadmium complexation and the impossibility of avoiding electrode adsorption problems in ASV measurements at very low metal concentrations. Figure DP anodic stripping and AC anodic stripping voltammograms at −12° and −65° during the titration of a 10⁻⁷ mol L⁻¹ Cd(II) solution with SRFA at pH 7.5 in 0.05 L⁻¹ Tris Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Identification and characterization of the chemical constituents of Simiao Wan by ultra high performance liquid chromatography with mass spectrometry coupled to an automated multiple data processing method

The chemical constituents of Simiao Wan (SW), a traditional Chinese medicine preparation, are difficult to determine and remain unclear. To more efficiently detect ions, a multiple data processing approach has been used in the characterization of the compounds. In this study, a rapid and sensitive method based on ultra high performance liquid chromatography with mass spectrometry and the multiple data processing approach was established to characterize the chemical constituents of SW. Ultra high performance liquid chromatography with mass spectrometry coupled with the multiple data processing approach could efficiently remove nonrelated ion signals from accurate mass data. We report the application of the multiple data processing approach for comprehensive detection and rapid identification of chemical constituents of SW. Of note, the total analysis time for separation was less than 20 min without losing any resolution. In the variable, importance in projection plot of orthogonal projection to latent structure‐discriminant analysis, a total of 72 ions of interest (37 ions in positive mode, 38 ions in negative mode and three ions in both mode) were extracted or tentatively characterized based on their retention times, exact mass measurement for each molecular ion and subsequent fragment ions. In summary, the methodology proposed in this study could be valuable for the structural characterization and identification of the multiple constituents in the traditional Chinese medicine formula SW.     

顶空固相微萃取-全二维气相色谱/飞行时间质谱法分析闽南乌龙茶中的挥发性成分及其在分类中的应用

采用顶空固相微萃取(HS-SPME)结合全二维气相色谱/飞行时间质谱(GC×GC-TOF MS)分析了闽南乌龙茶中的挥发性成分。从48份不同等级和产季的乌龙茶(铁观音、黄金桂、本山、毛蟹和梅占)中获得了2000余种挥发性化合物,经筛选得到51种共有组分,并结合质谱数据库、保留指数与结构谱图等进行了初步鉴定。在此基础上采用主成分分析法(PCA)获得得分投影图,直观给出了不同样品的分类趋势。通过逐步判别获得9种对分类结果有显著影响的组分,并以此为变量通过Fisher判别法(FDA)建立了4个判别函数,对样品的分类准确率达到97.9%。本试验证实了以挥发性成分识别闽南乌龙茶的可行性。