Water Quality and Mortality from Coronary Artery Disease in Sardinia: A Geospatial Analysis.

The role of water hardness on human health is still debated, ranging from beneficial to harmful. Before the rise of drinking bottled water, it was a common habit to obtain supplies of drinking water directly from spring-fed public fountains. According to the geographic location, spring waters are characterized by a variable content of mineral components. In this ecological study, for the first time in Sardinia, Italy, the spatial association between spring water quality/composition and standardized mortality ratio (SMR) for coronary artery disease (CAD) in the decade from 1981 to 1991 was investigated using data retrieved from published databases. In a total of 377 municipalities, 9918 deaths due to CAD, including acute myocardial infarction (AMI), ICD-9 code 410, and ischemic heart disease (IHD), ICD-9 code 411-414, were retrieved. A conditional autoregressive model with spatially structured random effects for each municipality was used. The average SMR for CAD in municipalities with a predominantly "soft" (<30 mg/L) or "hard" (≥30 mg/L) water was, respectively, 121.4 ± 59.1 vs. 104.7 ± 38.2 (p = 0.025). More specifically, an inverse association was found between elevated calcium content in spring water and cardiovascular mortality (AMI: r = -0.123, p = 0.032; IHD: r = -0.146, p = 0.009) and borderline significance for magnesium (AMI: r = -0.131, p = 0.054; IHD: r = -0.138, p = 0.074) and bicarbonate (IHD: r = -0.126, p = 0.058), whereas weak positive correlations were detected for sodium and chloride. The lowest CAD mortality was observed in geographic areas (North-West: SMR 0.92; South-East: SMR 0.88), where calcium- and bicarbonate-rich mineral waters were consumed. Our results, within the limitation of an ecological study, confirm the beneficial role of waters with high content in calcium and bicarbonate against coronary artery disease.

Geomorphology of the Mirador-Calakmul Karst Basin: A GIS-based approach to hydrogeologic mapping.

This paper classifies the karst landscapes of the Petén Plateau and defines the Mirador-Calakmul Karst Basin by illustrating the distribution of its karst hydrologic features. Archaeological and spatial research of the Mirador-Calakmul area of Guatemala and Mexico has shown it to be a karst basin with geopolitical implications. Current research characterizes the karst landscapes of the Petén Plateau, maps the distribution of karst hydrologic features, and delineates the basin in geomorphological terms. To further this aim, multiple forms of remote sensing data including orthophotographs, a satellite Digital Elevation Model, satellite multispectral images, and Light Detection and Ranging (LiDAR) data have been integrated to interpret the karst features in the study area. Outcrop study and thin section analysis of the upper Buena Vista Formation document that the dominant lithologies are a shallow water algal boundstone interbedded with terrestrial caliche. Karst landforms have been mapped over the Petén Plateau and we identify five karst landscapes, the largest of which is a fluviokarst landscape dominated by karst valleys. We further map karst hydrologic features including seasonal swamps, dolines, intermittent lakes, intermittent streams, solution-enhanced fractures, and springs all of which are characteristic of drainage basins. Boundaries of the karst basin are mapped from multiple lines of evidence including distribution of the karst valleys, a line of springs along the western boundary of the fluviokarst landscape, and a surface drainage analysis. We capture and classify hydrologic data points and develop a regional groundwater map that indicates subsurface flow from east to west within the basin. A drainage map illustrates the extensive system of karst valleys, boundaries, and inferred groundwater flow paths of the Mirador-Calakmul Karst Basin. It was within this geomorphological setting that the ancient Maya developed an extensive civilization during the Middle and Late Preclassic periods (1000 BCE-150 CE).

Boletim de Monitoramento Ambiental de SARS-CoV-2 no RS (3) / SARS-Cov-2 Environmental Monitoring Bulletin in RS (3)

O estudo visa disponibilizar aos órgãos de saúde informações sobre a circulação viral nas diferentes áreas do território avaliado, aumentando a compreensão da dinâmica viral na epidemia e auxiliando na tomada de decisão das medidas de distanciamento, além de fornecer elementos que contribuam para a investigação da hipótese de transmissão fecal-oral ou fecal-respiratória. Trata-se de um projeto multicêntrico, colaborativo, que conta com a participação de pesquisadores das Universidades Feevale e UFRGS e também do serviço público nas esferas federal, estadual e municipal - representando Fundação Oswaldo Cruz - FIOCRUZ, Centro Estadual de Vigilância em Saúde - CEVS, Fundação Estadual de Proteção Ambiental - FEPAM, Departamento Municipal de Água e Esgotos- DMAE e Secretaria Municipal do Meio Ambiente e da Sustentabilidade - SMAMS de Porto Alegre e Secretaria Municipal de Saúde de Novo Hamburgo nesta primeira etapa do projeto. (AU)

Boletim de Monitoramento Ambiental de SARS-CoV-2 no RS (2) / SARS-Cov-2 Environmental Monitoring Bulletin in RS (2)

O estudo visa disponibilizar aos órgãos de saúde informações sobre a circulação viral nas diferentes áreas do território avaliado, aumentando a compreensão da dinâmica viral na epidemia e auxiliando na tomada de decisão das medidas de distanciamento, além de fornecer elementos que contribuam para a investigação da hipótese de transmissão fecal-oral ou fecal-respiratória. Trata-se de um projeto multicêntrico, colaborativo, que conta com a participação de pesquisadores das Universidades Feevale e UFRGS e também do serviço público nas esferas federal, estadual e municipal - representando Fundação Oswaldo Cruz - FIOCRUZ, Centro Estadual de Vigilância em Saúde - CEVS, Fundação Estadual de Proteção Ambiental - FEPAM, Departamento Municipal de Água e Esgotos- DMAE e Secretaria Municipal do Meio Ambiente e da Sustentabilidade - SMAMS de Porto Alegre e Secretaria Municipal de Saúde de Novo Hamburgo nesta primeira etapa do projeto. (AU)

Heavy metal and metalloid contamination and health risk assessment in spring water on the territory of Belgrade City, Serbia.

The aim of this research was to examine the content of heavy metals and metalloids in the spring water on the territory of Belgrade City and their health risk. This paper presents results of the content and non-carcinogenic health risk assessment of aluminum, iron, chromium, manganese, nickel, copper, zinc, arsenic, cadmium, mercury and lead, as well as carcinogenic health risk assessment of arsenic, in untreated spring water on the territory of Belgrade City. 23 out of 30 registered and controlled springs in Belgrade City were sampled and examined. The analysis of all samples was done using an ICP-MS. Descriptive and multivariate statistical analysis of data was done, and based on Shapiro-Wilk test of normality, all data sets, from which mean values of heavy metals and metalloids were calculated, have normal distribution. Pearson's correlation coefficient for the examined elements was determined too, as well as spatial distribution and cluster analysis with dendrogram. Based on heavy metal and metalloid concentrations, the health risk assessment (HQ) was calculated. Although the concentrations of certain heavy metals and metalloids in untreated water were in a wide range of values and differed significantly, in a large number of springs concentrations of most of the investigated heavy metals and metalloids were lower than the maximum permissible concentrations prescribed by the legislation of the Republic of Serbia and do not show unacceptable non-carcinogenic and carcinogenic health risk.

Boletim de Monitoramento Ambiental de SARS-CoV-2 no RS (1) / SARS-Cov-2 Environmental Monitoring Bulletin in RS (1)

O estudo visa disponibilizar aos órgãos de saúde informações sobre a circulação viral nas diferentes áreas do território avaliado, aumentando a compreensão da dinâmica viral na epidemia e auxiliando na tomada de decisão das medidas de distanciamento, além de fornecer elementos que contribuam para a investigação da hipótese de transmissão fecal-oral ou fecal-respiratória. Trata-se de um projeto multicêntrico, colaborativo, que conta com a participação de pesquisadores das Universidades Feevale e UFRGS e também do serviço público nas esferas federal, estadual e municipal - representando Fundação Oswaldo Cruz - FIOCRUZ, Centro Estadual de Vigilância em Saúde - CEVS, Fundação Estadual de Proteção Ambiental - FEPAM, Departamento Municipal de Água e Esgotos- DMAE e Secretaria Municipal do Meio Ambiente e da Sustentabilidade - SMAMS de Porto Alegre e Secretaria Municipal de Saúde de Novo Hamburgo nesta primeira etapa do projeto. (AU)

RADON ACTIVITY CONCENTRATION IN WATERS OF SPRINGS IN SELECTED AREAS OF WESTERN SLOVAKIA.

This paper presents the results of measurements of radon activity concentration (RAC) in spring waters and natural wells in three mountains of Slovakia (Strázov Mountains, Povazský Inovec and Little Carpathians). These mountains provide drinking water for inhabitants of surrounding towns and villages. Little Carpathians is the most seismically active area in Slovakia. Povazský Inovec, where 2 out of 11 uranium deposits of Slovakia are located, is interesting due to increased uranium mineralization. We have collected samples from more than 170 natural water sources, many of which exceed the guide value of 100 Bq l-1, with a maximum value of 274 Bq l-1. The median of these data (15 Bq l-1) is also higher than the national median in groundwater (11.6 Bq l-1). From the obtained data, we have created maps representing RAC of groundwaters for the whole territory. These maps were also compared with the geological maps.

[Comparison of the Geochemical Characteristics of Karst Springs of a Vertically Zoned Climate Region under Human Activity: A Case of Shuifang Spring and Bitan Spring in the Jinfo Mountain Area, Chongqing].

To investigate the hydrochemical variation of karstic groundwaters in a vertically zoned climate region affected by human activity, Shuifang Spring and Bitan Spring in the Jinfo Mountain area of Chongqing were selected as a study site. Based on the differences between the natural state and intensity of human activity of these two springs, their hydrogeochemical characteristics and the controlling factors on karstic groundwaters were analyzed by means of independent sample t tests, the Gibbs graphic method, principle component analysis (PCA), and geochemical susceptivity analysis. The results show that differences in karst development in the vertical climatic zone leads to higher total ion concentrations in Bitan Spring than in Shuifang Spring. The hydrochemical types of Shuifang Spring and Bitan Spring are HCO3-Ca and HCO3-Ca·Mg, respectively, which reflect the lithology of their different elevations. Carbonate rock dissolution is the main source of Ca2+, Mg2+, and HCO3- in karstic groundwaters. Hotel sewage discharge supplies SO42-, NO3-, PO43-, K+, and Na+ in Shuifang Spring, which peaked in winter and summer, while hydrochemical parameters of Bitan Spring changed smoothly throughout the year. The water quality of Bitan Spring is better than Shuifang Spring (Shuifang Spring water is classified as Class Ⅳ). PCA shows that the water-rock interaction was the first controlling factor. Hotel sewage discharge and ions from precipitation had important effects on Shuifang Spring and Bitan Spring, respectively. In addition, the effects of soil erosion and leaching caused by precipitation also impact on the water quality of two springs to some extent. The geochemical susceptibility of Shuifang Spring was greater than that of Bitan Spring; therefore, corresponding measures should be formulated according to the characteristics of these differently elevated karst systems when exploiting groundwater resources. This is especially the case for the treatment of hotel sewage.

Contaminant sources and processes affecting spring water quality in a typical karst basin (Hongjiadu Basin, SW China): insights provided by hydrochemical and isotopic data.

Springs are an important source of drinking water supply in mountainous karst areas of SW China. However, the quality of many spring waters has deteriorated greatly in recent years, which leads to a significant problem of drinking water scarcity. In this study, hydrochemistry and stable sulfur and oxygen isotopic compositions of SO42- (δ34S and δ18OSO4) of 38 representative samples of waters (incl. spring water, surface water, rainwater, and sewage) from the Hongjiadu Basin, Guizhou province, SW China, were investigated in order to identify the sources of contaminates in spring waters and trace the processes affecting the karst groundwater quality. Approximately 28% of the total investigated springs has been suffered from serious contamination and the concentrations of NO3-, SO42-, and total iron (TFe) in many spring waters have exceeded the standards for drinking water. The springs that have NO3- concentrations of > 30 mg/L are concentrated in residential and agricultural areas, suggesting that NO3- in spring water are mainly derived from chemical fertilizers, manure, and sewage. δ34S and δ18OSO4 data indicate that SO42- in spring water mainly originates from sulfide oxidation, acid rain, and sewage. Furthermore, the high δ34S and δ18OSO4 values of SO42- in some spring waters may be related to the occurrence of bacterial sulfate reduction. Some springs that are discharged from abandoned coal mines have SO42- concentrations of > 250 mg/L, demonstrating that mining activities have accelerated the deterioration of spring water quality. Also, springs with TFe concentrations of > 0.3 mg/L are discharged from coal-bearing strata, revealing that iron in spring waters is mainly derived from the oxidation of pyrite. Our results show that the karst spring waters are highly vulnerable to anthropogenic contaminations and human activities, such as agricultural fertilizing and sewage and waste disposal as well as mining activities, which exert a great impact on the quality of groundwater in karst areas.

Groundwater of the Crimean peninsula: a first systematic study using stable isotopes.

Karst springs in the Main Range of the Crimean Mountains and the Crimean Piedmont show a restricted range of values (δ18O = -10.5 to -8.0 ‰, δ2H = -72 to -58 ‰), somewhat more negative than the weighted mean of meteoric precipitation. This suggests preferential recharge at higher elevations during winter months. Groundwater tapped by boreholes splits in three groups. A first group has isotopic properties similar to those of the springs. The second group shows significantly lower values (δ18O = -13.3 to -12.0 ‰, δ2H = -95 to -82 ‰), suggesting recharge during colder Pleistocene times. The third group has high isotope values (δ18O = -2.5 to +1.0 ‰, δ2H = -24 to -22 ‰); the data points are shifted to the right of the Local Meteoric Water Line, suggesting water-rock exchange processes in the aquifer. These boreholes are located in the Crimean Plains and discharge mineralized (ca. 25 g L-1) thermal (65°C) water from a depth of 1600-1800 m. Groundwater associated with mud volcanoes on the Kerch peninsula have distinct isotope characteristics (δ18O = -1.6 to +9.4 ‰, δ2H = -30 to -18 ‰). Restricted δ2H variability along with variable and high δ18O values suggest water-rock interactions at temperatures exceeding 95 °C.

Quality of Drinking Water from Springs in Palestine: West Bank as a Case Study.

The shortage of fresh water creates acute challenges in the West Bank of Palestine. Springs provide a main water resource in the West Bank. Investigating springs' water quality is essential step for promoting their public use. The aim of this research is to assess the microbiological and physiochemical quality parameters of drinking water from springs. The study methodology included sampling through field work and laboratory testing for water quality parameters using standard procedures. The study area covered all locations containing licensed springs by the Palestinian Water Authority in the West Bank of Palestine. The number of collected samples was 127 covering 300 springs. The chemical, physical, and biological parameters for each sample were measured. Then, the obtained characteristics were evaluated based on national and international quality standards (PSI and WHO). The investigated parameters included temperature, pH, EC, total hardness, concentrations of nitrate, sodium ions, total chlorine, residual chlorine, turbidity, and total and faecal coliforms. Most of investigated physical and chemical parameters were within the acceptable standard limits. However, the turbidity and chloride and nitrate concentrations exceeded standard limits. The findings indicate that only a minor fraction of the samples (2%) requires chlorination treatment, while most of the springs (97% of samples) are classified as possessing no risk.

Hydrogeological responses in tropical mountainous springs.

This study presents a hydrogeochemical analysis of spring responses (2013-2017) in the tropical mountainous region of the Central Valley of Costa Rica. The isotopic distribution of δ18O and δ2H in rainfall resulted in a highly significant meteoric water line: δ2H = 7.93·Î´18O + 10.37 (r2 = 0.97). Rainfall isotopic composition exhibited a strong amount-dependent seasonality. The isotopic variation (δ18O) of two springs within the Barva aquifer was simulated using the FlowPC program to determine mean transit times (MTTs). Exponential-piston and dispersion distribution functions provided the best-fit to the observed isotopic composition at Flores and Sacramento springs, respectively. MTTs corresponded to 1.23 ± 0.03 (Sacramento) and 1.42 ± 0.04 (Flores) years. The greater MTT was represented by a homogeneous geochemical composition at Flores, whereas the smaller MTT at Sacramento is reflected in a more variable geochemical response. The results may be used to enhance modelling efforts in central Costa Rica, whereby scarcity of long-term data limits water resources management plans.

A simple field method for the determination of sulfite in natural waters: Based on automated dispersive liquid-liquid microextraction coupled with ultraviolet-visible spectrophotometry.

Sulfite is known to be harmful to human health and associated to sulfur related environmental effects and ideally should be analyzed onsite owing to its instability. Here we describe an automated, miniaturized, and highly efficient dispersive liquid-liquid microextraction (DLLME) system that seamlessly coupled to a UV-vis spectrophotometer for the trace analysis of sulfite in natural waters. The automated DLLME system was constructed by a single syringe pump that is coupled with a multiposition valve. Nanomolar levels of sulfite could be extracted from natural water samples and injected into the hyphenated spectrophotometer for quantification. The whole analytical procedures, including chromogenic reactions, DLLME, collecting and transferring of microvolume of extracts, and spectrophotometric quantification, were automatically carried out. Key parameters that affect the performance of the method were investigated. The method allows the determination of trace levels of sulfite in the range of 15-1500 nM with a detection limit of 1.2 nM. Good reproducibility and recoveries were obtained by analyzing a series of natural water samples that were spiked with different concentration levels. The method was successfully applied to real natural water samples with satisfactory results. The proposed analytical system is light (3.9 kg), simple to use, able to be applied in the field, and sensitive enough for fresh and saline waters analysis.

The sources and dispersal of nitrate in multiple waters, constrained by multiple isotopes, in the Wudalianchi region, northeast China.

The Wudalianchi scenic area in NE China has been named an UNESCO "Global Geopark" and "Biosphere Reserve." During this investigation, the sources of nitrate and the hydrologic system through which it is dispersed were assessed using geochemical data and a multiple isotopic approach. The cold waters from the south and north springs originated from the deep subsurface. Isotopically, these waters exhibited relatively negative δD and δ18O values and nitrate in the water was substantially depleted 15N, suggesting that the mineral water was primarily derived from depth. Lakes within the Wudalianchi region were primarily composed of water from these deep mineral springs and precipitation. Chemical fertilizers were the primary source of nitrate to the Wudalianchi lakes. Groundwater was found in shallow mineral springs and wells plotted above the local meteoric water line, implying that shallow groundwater was primarily derived from precipitation. Elevated concentrations of nitrate in shallow mineral springs and well waters during the summer, autumn, and winter suggest that shallow groundwater within the Yaoquan volcanic area was also polluted by nitrate from human activities. Denitrification of shallow groundwater is slow, reducing the potential for "self-remediation". The concentration data are supported by nitrogen (N) isotope data; wells and springs exhibited N isotopic ratios between - 5‰ and + 5‰ (typical of fertilizers and precipitation) and exhibited higher oxygen (O) isotope values than water in the Wudalianchi lakes. These relationships suggest that nitrate in shallow mineral springs, wells, and lakes near the Yaoquan volcano was derived from the mixing of chemical fertilizers with local summer rainfall.

Vascular plant and bryophyte species richness in response to water quality in lowland spring niches with different anthropogenic impacts.

Many freshwater ecosystems face severe threats from anthropogenic disturbances. In the field, we investigated the morphology of spring niches and the species richness of vascular plants and bryophytes in 16 springs, draining the quaternary aquifers, located in two different environments-an urban area (city of Bialystok) and a protected area (Knyszyn Forest Landscape Park, NE Poland). In total, 47 vascular plant and 45 bryophyte species were recorded, representing mostly crenophytes including protected species. The most important water quality parameters that can be used to evaluate variations of the spring water chemistry in NE Poland are the mineral-related parameters (electrolytic conductivity, Ca2+, SO42-, and Cl-). The organic-related parameters (DOC) and nutrients (TP, NO3--N) were negatively involved in water quality variations. Our results show that anthropogenic activity significantly affects the biodiversity of plant communities in lowland springs. The presence or absence of crenophytes and bryophytes is indicative of the ecological status of the groundwater outflow complexes.

Do natural spring waters in Australia and New Zealand affect health? A systematic review.

Therapeutic use of spring waters has a recorded history dating back to at least 1550 BC and includes both bathing in and drinking such waters for their healing properties. In Australia and New Zealand the use of therapeutic spring waters is a much more recent phenomenon, becoming a source of health tourism from the late 1800s. We conducted a systematic review aimed at determining the potential health outcomes relating to exposure to Australian or New Zealand natural spring water. We found only low-level evidence of adverse health outcomes relating to this spring water exposure, including fatalities from hydrogen sulphide poisoning, drowning and primary amoebic meningoencephalitis. We found no studies that investigated the therapeutic use of these waters, compared with similar treatment with other types of water. From the broader literature, recommendations have been made, including fencing potentially harmful spring water, and having signage and media messages to highlight the potential harms from spring water exposure and how to mitigate the risks (e.g. not putting your head under water from geothermal springs). Sound research into the potential health benefits of Australian and New Zealand spring waters could provide an evidence base for the growing wellness tourism industry.

Evaluation of Environmental Risk Due to Metro System Construction in Jinan, China.

Jinan is a famous spring city in China. Construction of underground metro system may block groundwater seepage, inducing the depletion risk of springs. This paper presents an assessment of the risk due to metro line construction to groundwater in Jinan City using Analytic Hierarchy Process (AHP) and Geographic International System (GIS). Based on the characteristics of hydrogeology and engineering geology, the assessment model is established from the perspectives of surface index and underground index. The assessment results show that the high and very high risk levels of surface index exceed 98% in the north region; and high and very high risk levels of underground index exceed 56% in urban center and southern region. The assessment result also shows that about 14% of the urban area belongs to very high risk level; regions of high risk are 20% in urban area, 9% in Changqing County and 43% in Pingyin County. In the high risk region, metro lines R1 to R3, which are under construction, and metro lines L1 to L5, which are planned, have very high and high risk. Therefore, risk control measures are proposed to protect the groundwater seepage path to spring.

Unusual metabolic diversity of hyperalkaliphilic microbial communities associated with subterranean serpentinization at The Cedars.

Water from The Cedars springs that discharge from serpentinized ultramafic rocks feature highly basic (pH=~12), highly reducing (Eh<-550 mV) conditions with low ionic concentrations. These conditions make the springs exceptionally challenging for life. Here, we report the metagenomic data and recovered draft genomes from two different springs, GPS1 and BS5. GPS1, which was fed solely by a deep groundwater source within the serpentinizing system, was dominated by several bacterial taxa from the phyla OD1 ('Parcubacteria') and Chloroflexi. Members of the GPS1 community had, for the most part, the smallest genomes reported for their respective taxa, and encoded only archaeal (A-type) ATP synthases or no ATP synthases at all. Furthermore, none of the members encoded respiration-related genes and some of the members also did not encode key biosynthesis-related genes. In contrast, BS5, fed by shallow water, appears to have a community driven by hydrogen metabolism and was dominated by a diverse group of Proteobacteria similar to those seen in many terrestrial serpentinization sites. Our findings indicated that the harsh ultrabasic geological setting supported unexpectedly diverse microbial metabolic strategies and that the deep-water-fed springs supported a community that was remarkable in its unusual metagenomic and genomic constitution.

Quality survey of natural mineral water and spring water sold in France: Monitoring of hormones, pharmaceuticals, pesticides, perfluoroalkyl substances, phthalates, and alkylphenols at the ultra-trace level.

The aim of the present study, one of the most complete ever performed in France, was to carry out an extensive survey on the potential presence of a large amount of emerging contaminants in 40 French bottled waters, including parent compounds and metabolites. The studied samples represented 70% of the French bottled water market in volume. Six classes of compounds were investigated, most of them being unregulated in bottled waters: pesticides and their transformation products (118), pharmaceutical substances (172), hormones (11), alkylphenols (APs) (8), phthalates (11) and perfluoroalkyl substances (PFAS) (10). One of the objectives of this work was to achieve low and reliable limits of quantification (LOQs) (87% of the LOQs were below 10ng/L) using advanced analytical technologies and reliable sample preparation methodologies, including stringent quality controls. Among the 14,000 analyses performed, 99.7% of the results were below the LOQs. None of the hormones, pharmaceutical substances and phthalates were quantified. Nineteen compounds out of the 330 investigated were quantified in 11 samples. Eleven were pesticides including 7 metabolites, 6 were PFAS and 2 were APs. As regards pesticides, their sum was at least twice lower than the quality standards applicable for bottled waters in France. The presence of a majority of pesticide metabolites suggested a former use in the recharge areas of the exploited aquifers. The quantification of a few unregulated emerging compounds at the nano-trace level, such as PFAS, raised the issue of their potential sources, including long-range atmospheric transport and deposition. This study confirmed that the groundwater aquifers exploited for bottling were well-preserved from chemicals, as compared to less geologically protected groundwaters, and also underlined the need to pursue the protection policies implemented in recharge areas in order to limit the anthropogenic pressure.

Liquid-phase microextraction of organophosphorus pesticides using supramolecular solvent as a carrier for ferrofluid.

A liquid-phase microextraction based on application of supramolecular solvent as a carrier for ferrofluid has been developed for the extraction and determination of three organophosphorus pesticides (OPPs). The ferrofluid was produced from combination of oleic acid coated magnetic particles and supramolecular solvent as the extractant solvent. Ferrofluid can be attracted by a magnet, and no centrifugation step was needed for phase separation. A response surface methodology (RSM) based on central composite design (CCD) was used for efficient optimization of the main variables in the extraction procedure. Under the optimum experimental conditions, the calibration curves found to be linear in the range of 0.5-400µgL(-1) with correlation coefficients ranging from 0.9967 to 0.9984. The intra-day and inter-day precision (RSD %) for 100 and 200µgL(-1) of each pesticides were in the range of 2.0-5.3% and 2.6-5.7%, respectively. The limit of detection (S/N=3), ranged from 0.1 to 0.35µgL(-1). The proposed method was successfully applied to the extraction and determination of organophosphorus pesticide residues in water and fruit juice samples.