Samples Of Aquatic Plants Research Articles

Development of a closed tube loop-mediated isothermal amplification (LAMP) assay to detect Hirschmanniella oryzae (Tylenchida: Pratylenchidae) in exported aquatic plants

Rice root nematode, Hirschmanniella oryzae is an important plant-parasitic nematode inflicting substantial destruction on economically important agricultural crops worldwide and invading an extensive range of plant hosts, including aquatic plants. However, morphological identification of the nematode has encountered limitations. This study developed a loop-mediated isothermal amplification (LAMP) assay targeting the genetic sequence of H. oryzae 28S ribosomal RNA gene as an alternative method. The LAMP assay demonstrated remarkable speed that the outcome could be achieved within 40 min at an isothermal temperature, 65 °C. The assay could interpret the fluorescence (SYBR safe) and color (SYBR green I) in a pre-reaction mixture, ensuring reliability and minimizing contamination risk during post-amplification. Our assay has high specificity and enables accurate differentiation from other nematode species in diverse aquatic plant samples. The sensitivity was higher than PCR and real-time PCR as low as 4.61 fg/μL. The development of fluorescent and colorimetric closed tube LAMP assay highlights it as a valuable tool that is a simplified, sensitive and rapid diagnostic method for detecting aquatic pest nematode, H. oryzae, at point-of-service level. The implementation of this method holds promise for future applications in plant quarantine departments and offers a significant advancement in the diagnosis of infected plants.

Accumulation and Phytoremediation Potentiality of Trace and Heavy Metals in Some Selected Aquatic Plants from a Highly Urbanized Subtropical Estuary

The global concern over trace and heavy metal contamination in aquatic environments necessitates the development of effective remediation strategies. Using aquatic plants for heavy metal removal is a relatively economical and sustainable technology worldwide. This study involved collecting sediment and aquatic plant samples (Acanthus ilicifolius, Typha elephantina, and Cynodon dactylon) from a highly urbanized estuary to analyze metal concentrations in sediment, assess ecological risks, and explore the phytoremediation potential. Trace and heavy metals were detected using Energy Dispersive X-ray Fluorescence Spectroscopy (EDXRF). The sediment metal concentrations were found in decreasing order of Fe, Ti, Mn, Rb, Zr, Zn, Sr, Cu, Co, and As. Fe, Sr, and As concentrations were below certified values, whereas Cu, Zn, and Rb exceeded them. Cumulatively, the pollution load index (PLI) values were close to 1 (0.845), indicating that the study area is likely experiencing metal pollution. The Contamination Factor (CF) values, ranging from 1 to 3, indicated a moderate degree of sediment pollution for Ti, Mn, Cu, Zn, and Rb. The Enrichment Factor (EF) values similarly showed moderate enrichment for these metals, with Cu exhibiting the highest degree of enrichment. Ecological risk assessment highlighted the only metal, Cu, as posing the greatest risk among the studied metals. In terms of phytoremediation potential, the bioconcentration factor (BCF) followed the decreasing order of C. dactylon > A. ilicifolius > T. elephantina for most metals, with low BCF values (<1) indicating low accumulator potential. However, the translocation factor (TF) values for Zn (1.464) and Rb (1.299) in A. ilicifolius species were greater than 1, indicating low accumulation potential but hyper-metabolizing capabilities, allowing the plant to accumulate metals in its aerial parts, making it effective for phytostabilization.

Accumulation of Heavy Metals by Some Aquatic Macrophytes in Two Streams along the Tiko-Douala Highway, Cameroon

Aims: This study was aimed at determining the ecological health of two roadside streams across the Tiko-Douala highway, Cameroon, and investigating the phytoremediation potentials of dominant aquatic macrophytes within these streams.
 Study Design: Water, sediments, and aquatic plant samples were collected from Camp 7 and Moqouo streams, and analyzed for ammonium nitrogen, nitrate nitrogen, phosphates, magnesium, cadmium, and lead, including other relevant water quality parameters.
 Place and Duration of Study: In the Life Science Laboratory of the University of Buea, and Soil and Water Laboratory of the University of Dschang, Cameroon between June 2021 and June 2022.
 Methodology: Six water samples and six sediment samples were collected per stream, and two of the most dominant plant species (Pennisetum purpureum Schumach (Poaceae) and Dicanthelium clandestinum L. (Poaceae) from Camp 7, Commelina benghalensis L. (Commelinaceae) and Oldenlandia corymbosa L.(Rubiaceae) from Moqouo stream) were collected for heavy metal analysis. Heavy metal concentration and bioaccumulation factors were determined for each plant.
 
 Results: High concentrations of phosphates were recorded in Camp 7 (1.19 mg/L) and Moqouo (2.17 mg/L) streams. Dissolved oxygen levels were 0.69 mg/L and 0.80 mg/L in Camp 7 and Moqouo respectively. Sediment cadmium levels ranged from 0.33± 0.02 to 0.63± 0.16 mg/kg, and lead ranged from 0.34 ±0.03 to 0.37 ± 0.12 mg/kg in Moqouo and Camp 7 respectively. 
 Conclusion: The Mouqouo and Camp 7 streams are rich in phosphates and thus not suitable for drinking and irrigation. Cadmium and lead in stream water were within the permissible limits but sediments contained higher concentrations than water and therefore they could be released gradually into the water column. All plants in the study except (Dicanthelium cladestinum) accumulated cadmium and lead, and could be potential plants for the phytoremediation of these metals.

Occurrence, bioaccumulation and ecological risks of antibiotics in the water-plant-sediment systems in different functional areas of the largest shallow lake in North China: Impacts of river input and historical agricultural activities.

Antibiotics are widely used and ubiquitous in the environment, which in turn poses potential threat to human health. However, the effects of agricultural activities and river input on the fate and ecological risks of antibiotics in shallow lake are still poorly understood. Surface water, overlying water and pore water, sediments and aquatic plant samples in the historical planting subarea (PA), historical aquaculture subarea (AU), inflow subarea (IW), discharge subarea (DC), and conservation subarea (CK) of Baiyangdian Lake were collected and analyzed. Our results revealed that the total antibiotic concentrations ranged from 85.33 ng/L to 1631.47 ng/L in waters and from 66.90 ng/g to 177.03 ng/g in sediments. Generally, the total antibiotic concentrations introduced by planting activity in surface water, overlying water and sediments were higher and the levels of total antibiotics in pore water were more affected by river input. In addition, three quinolones (QNs) and two tetracyclines (TCs) were dominant antibiotics in almost five subareas. The pseudo-partitioning coefficient kd(pw) and bioaccumulation factor (BAF) of antibiotics varied according to the effects of river input and historical agricultural activities. The ecological risk (RQ) of antibiotics from agricultural activities was higher than that from river input. The norfloxacin (NOR) in pore water showed high RQ, which contributed to a large proportion (>50 %) of the combined ecological risks (∑RQs) except for surface water. Therefore, NOR should be used as the primary ecological risk control index for antibiotic contamination management in the BYD. ∑RQs showed high risk in water in the five subareas. This study can act as a reference for governments to formulate effective management strategies for protecting the ecological health of lakes.

Comparison of molecular distributions and carbon and hydrogen isotope compositions of n-alkanes from aquatic plants in shallow freshwater lakes along the middle and lower reaches of the Yangtze River, China

Leaf wax n-alkanes in lacustrine sequences have been widely applied for reconstructions of Late Quaternary paleoclimate histories. Such applications depend on knowledge of the factors controlling the characterization of the n-alkane paleoproxies of aquatic plants. This study analyzed the molecular distributions and carbon and hydrogen isotopic compositions of n-alkanes of aquatic plant samples collected from the middle and lower reaches of the Yangtze River (MLYR). In this collection, the n-alkane distributions of submersed/floating plants and emersed plants are distinctly different. By combining their Paq and n-alkane δ13C values, the n-alkane contributions from submersed plants and emersed plants in the MLYR can be differentiated. It is also noteworthy that the hydrogen isotope fractionation (εalk/water; avg. −166‰) between the n-C23 alkane of submersed plants in the MLYR and in precipitation agrees well with previous studies, suggesting a nearly constant εalk/water for the submersed plants. Moreover, compared to C3 dicots growing in a similar climate, submersed plants in the humid MLYR have lower n-alkane δ2H values. This feature may arise from isotopic differences in the evapotranspiration of lake water versus leaf water and in the biosynthetic fractionations of leaf waxes of these two plant groups. These results aid interpretations of the hydrogen isotope offset of the δ2H values of n-alkanes between aquatic and terrestrial plants in humid climates.

Pollution of aquatic plants with Lead and Cadmium by the effect of adding cities waste in Al-Diwaniyah River / Iraq

This study was conducted to find out the effect of adding sewage and industrial water on the concentration of Lead and Cadmium elements in aquatic plants during different seasons of the year in Diwaniyah governorate / Iraq. Aquatic plant samples (Arundo and Ceratophyllum) were collected in three replications for all sites and during four seasons: summer (July) 2019, autumn (October) 2019, winter (January) 2020, spring (April) 2020, by three Sites where the first site is located at the entrance to the city of Diwaniyah (the Sania district), which represents the control treatment as it is located before the various pollution ports that pour into the river (such as sewage, hospital waste, factory waste, sewage … etc) and the second site in the city center (Rifaat quarter). The third site is in the Sudair district, which represents the last site of the city of Diwaniyah after the end of all the estuaries and sources of pollution. The results of the study found that the concentration of the two elements (Lead and Cadmium) in aquatic plants (Arundo and Ceratophyllum) increased with the increase of the river’s slope and the increase of the added pollutants. In the summer, the concentration of Lead in the Arundo plant was 6.79 μg.Kg−1, while its concentration in the Ceratophyllum plant was 7.80 μg.kg−1 in the third site and least in the winter season, for both plants, where the Lead concentration in the Arundo plant was 1.21 μg.Kg−1 and its concentration in Ceratophyllum plant is 1.52μg.Kg−1 in the first site. As for the highest concentration of Cadmium, it was in the summer also, it was 4.04 μg.Kg−1 in the Arundo plant, while it was 4.39 μg in the Ceratophyllum plant. in the third site and the lowest in the winter season, and for both plants, the Cadmium concentration in the Arundo plant reached 1.26 μg.Kg−1 As for its concentration in the Ceratophyllum plant, it was 1.43 μg.Kg−1 in the first site. The Ceratophyllum plant exceeded its absorption of Lead and Cadmium in all the studied sites and seasons.

Management of aquatic plants and their contributions to fisheries production in Ikere-Gorge, Iseyin, Oyo State, Nigeria

Aquatic plants are important in freshwater ecosystems. They provide food, shelter, spawning and nursery grounds for fish. They are usually found at the littoral parts of freshwater ecosystems. The abundance, distribution and diversity of aquatic plant of Ikere-gorge, Iseyin, Nigeria were examined between January 2017 and December 2018. There are twelve fishing villages in Ikere-gorge and four villages were randomly selected. Aquatic plants were sampled and collected with the help of hired fishermen. The collected aquatic plant samples were identified at the Forest Herbarium of the Forestry Research Institute of Nigeria with appropriate keys. This work identified 13 families and 23 species of aquatic plants. Cyperaceae family recorded the highest (4) number of individual species while Salvinia molesta had the highest abundance in all the sampling sites. The ecological classification of the aquatic plants showed that 14 species are emergent; 7 species floating and 3 species submerged. Site C had the most abundance (9220) of aquatic plants, followed by site D (8490), site B (8130) and site A (7940). The gamma (γ) and beta (β) diversities were 23 and 0.01 respectively. The alpha (α) diversity included Dominance (0.08), Simpson (0.92) and Shannon-Wiener (2.72) respectively. These results show that Salvinia molesta and Najas guadalupensis are the most and least abundant aquatic plants in Ikere-gorge respectively; which may be due to their ecological status. Moreover, management of aquatic plants is an integral part of fisheries management for sustainable fisheries. Therefore, their management is essential for the maintenance of aquatic biodiversity.
 Key words: aquatic plants, diversity, emergent, floating, submerged

Identification Of Aquatic Plant Species From Bantimurung Waterfall And Their Phytochemical Compounds Analysis

A total of 21 aquatic plant species were collected from Bantimurung waterfall areas, South Sulawesi, Indonesia, in October 2017. These plant materials were subjected to both species and phytochemicals identification. The aims of this study were to determine the species or taxonomic rank of Indonesian aquatic plants collected from Bantimurung waterfall, South Sulawesi, Indonesia and to identify their chemical compounds (phytochemicals) as a candidate for new herbal medicine. Plant genetic materials used in this study were collected from Bantimurung Bulusaraung waterfall and were then identified based on standard botanical techniques for species identification in the Herbarium Bogoriense, Research center for Biology Indonesian Institute of Science (LIPI), Cibinong, West Java. The samples were subjected to the phytochemistry screening such as alkaloids, flavonoids, tannins, saponins, glycosides, terpenoids and anthraquinone followed the procedures of Indonesian Materia Medika and Harborne. Results showed that all collected aquatic plant samples were able to be identified, including their species names. Phytochemical screening of each sample revealed the presence of glycoside in all of the tested species. However, no alkaloids, anthraquinones, and terpenoids were observed in those tested plant samples. Of the total 21 aquatic plants, 14 species contained flavonoids, 8 species contained phenol compound, and 10 species contained saponins. Among these species Donnax canniformis possessed good antioxidant activity, which correlated to its total phenolic and flavonoid contents. Our results would be beneficial for any future effort in the development of new herbal drugs derived from aquatic plants.

Antimicrobial Efficacy and Phytochemical Analysis of Three Aquatic Plant Species in Bangladesh

Aquatic plants are generally considered as breeding grounds for mosquitoes and other harmful vectors of diseases. However, in recent years, some research has been carried out to test their significance as sources of antimicrobial lead molecules. The aim of this research was to study the phytochemical composition of local aquatic plant species and test their antimicrobial effect against selected bacterial strains. Three different aquatic plant samples were collected from a large water body near Dhaka. Ethanol and ethyl acetate extracts of the plant species: Eichhornia crassipes, Pistia stratiotes, and Spirodela polyrrhiza were tested against Staphylococcus aureus, Salmonella typhi, and Lactobacillus spp. Out of the eight different extracts, only the ethyl acetate extracts prepared from Eichhornia crassipes showed significant anti-microbial activity against Staphylococcus aureus and Salmonella typhi. In disk diffusion tests, zone of inhibitions of ethyl acetate extracts of Eichhornia crassipes leaves and stems were 8.00 ± 0.5 mm and 7.83 ± .29 mm respectively. In well diffusion tests, zone of inhibitions of ethyl acetate extracts of Eichhornia crassipes leaves and stems were 18.00 mm and 20.00 mm respectively. Zones of inhibition of ethyl acetate extracts of Eichhornia crassipes stems against Staphylococcus aureus were 7.67 ± 0.29 mm and 12.00 mm respectively in disk and well diffusion tests. Zone of inhibition of ethyl acetate extracts of Spirodela polyrrhiza was 8.17 ± 0.29 mm against Staphylococcus aureus in disk diffusion tests. No extracts showed any antimicrobial potential against Lactobacillus. Phytochemical composition analysis showed the presence of alkaloids, flavonoids, steroids, phenolics, tannins, glycosides, and cardiac glycosides in the different ethanol and ethyl acetate extracts. Tannins were absent in all extracts and saponins were absent in all ethyl acetate extracts.
 Bangladesh J Microbiol, Volume 35 Number 1 June 2018, pp 7-11

Above-bottom biomass retrieval of aquatic plants with regression models and SfM data acquired by a UAV platform – A case study in Wild Duck Lake Wetland, Beijing, China

Above-bottom biomass (ABB) is considered as an important parameter for measuring the growth status of aquatic plants, and is of great significance for assessing health status of wetland ecosystems. In this study, Structure from Motion (SfM) technique was used to rebuild the study area with high overlapped images acquired by an unmanned aerial vehicle (UAV). We generated orthoimages and SfM dense point cloud data, from which vegetation indices (VIs) and SfM point cloud variables including average height (HAVG), standard deviation of height (HSD) and coefficient of variation of height (HCV) were extracted. These VIs and SfM point cloud variables could effectively characterize the growth status of aquatic plants, and thus they could be used to develop a simple linear regression model (SLR) and a stepwise linear regression model (SWL) with field measured ABB samples of aquatic plants. We also utilized a decision tree method to discriminate different types of aquatic plants. The experimental results indicated that (1) the SfM technique could effectively process high overlapped UAV images and thus be suitable for the reconstruction of fine texture feature of aquatic plant canopy structure; and (2) an SWL model based on point cloud variables: HAVG, HSD, HCV and two VIs: NGRDI, ExGR as independent variables has produced the best predictive result of ABB of aquatic plants in the study area, with a coefficient of determination of 0.84 and a relative root mean square error of 7.13%. In this analysis, a novel method for the quantitative inversion of a growth parameter (i.e., ABB) of aquatic plants in wetlands was demonstrated.

Bioaccumulation of Heavy Metals in Hydromacrophytes from Five Coastal Lakes (North-Western Poland, Baltic Sea)

The study concerned Polish coastal lakes separated from the Baltic Sea by a sandbar. The study was designed to determine whether the aquatic plants in the coastal lakes in Poland accumulate Cu, Ni, Cd. The material consisted of water and aquatic plant samples collected in the years 2012 and 2013 in lakes Resko Przymorskie, Jamno, Bukowo, Kopań and Wicko. The metal with the lowest content (mg.kg−1) in the plants was Cd, and the concentrations can be arranged as follows: Cd < Ni < Cu (mean 0.46 < 1.91 < 5.56) in 2012 and (mean 1.04 < 1.86 < 4.68) in 2013. For water, the order of concentrations (mg.l−1) of metals was follows: Cd < Ni < Cu (mean 0.0010 < 0.0033 < 0.0035) in 2012 and Cd < Cu < Ni (mean 0.0036 < 0.0107 < 0.0115) in 2013. The metal bioaccumulation in hydro‑macrophytes expressed by means of a bioaccumulation factor (BCF) was as follows: Cd < Ni < Cu (mean 474 < 1447 < 1519) in 2012 and Ni < Cd < Cu (mean 201 < 369 < 542) in 2013. The metal concentrations in samples were found comparable with those in moderately polluted surface waters. Statistically significant regression was only found between Cd concentration in water and in plants (R = 0.3484). Conductivity does not affect metals content in samples. Statistically significant differences were noted between water reaction and the content of all metals in water, and Cd content in case of the plants.

Bioaccumulation of Aluminium in Hydromacrophytes in Polish Coastal Lakes

Abstract The research on aluminium content was conducted in water and on aquatic flora of Polish lakes in the central part of the coast. The study included the lakes Sarbsko, Choczewskie, Bia.e, K.odno, D.brze and Salino investigated in the summer of 2013. The examined lakes belong mainly to the direct basin of the Baltic Sea. Samples of aquatic plants and lake waters were collected. In the water samples pH and electrolytic conductivity were measured. The aluminium content was determined both in water and aquatic plants. Submerged hydromacrophyte studies included Myriophyllum alterniflorum L., Potamogeton perfoliatus L. and Ceratophyllum demersum L. Emergent hydromacrophyte studies included Phragmites australis (Cav.) Trin. ex Steud., Juncus bulbosus L., Iris pseudacorus L., Eleocharis palustris (L.) Roem. % Schult., Phalaris arundinacea L., Carex riparia Curt., Mentha aquatic L., Stratiotes aloides L., Alisma plantago-aquatica L., Glyceria maxima (Hartman) Holmb., Sagittaria sagittifolia L., Scirpus lacustris L. and Typha angustifolia L. The purpose of this investigation was the determination of the aluminium content in submerged and emergent hydromacrophytes and also the definition of their bioaccumulative abilities. The average concentration of aluminium in water was 2.68 fęg Al dm.3. The average content of aluminium in plants was 2.8015 mg Al kg.1. The bioaccumulation factor ranged from BCF=19.74 to BCF=16619. On the basis of the analysis of the aluminium content in water and aquatic plants results show that both water and plants were characterized by a moderate level of aluminium. The recorded concentrations indicate a mid-range value and are much lower than those which are quoted for a variety of surface waters in various parts of the world.

Study of Naidid worms community associated with two species of aquatic plants in River Tigris inside Baghdad City / Iraq

The present study is concern with the interaction between the naidid worms diversity and the species of aquatic plant within which the worms found . For this purpose, two species of aquatic plant were used, Ceratophyllum demersum and Eichhornia crassipes. 12 samples of aquatic plants were collected , as one sample monthly for a period from September 2012 to September 2013 from different site on Tigris river within Baghdad City. From C. demersum, 1428 individuals, were sorted during the study period, related to 17 species. 12 species of subfamily Naidinae which are Chaetogaster limnaei , C. diastrophus , Ophidonais serpentine , Dero ( Dero) digitata. , D.(D.) evelinae , Nais pseudobtosa , N.simplex, N.stolci , N.Paradalis , N.elingius , N. variabilis and N. communis. In addition to five species of subfamily Pristininae, two species of Pristina , which are P. longiseta and . P. aequiseta, and three species of pristinella, which are P. . Jenkinae , P. sima , and P. osborni. Dero ( Dero) digitata was recorded the higher number of 430 individuals,with a percentage of 28.11% of the total sorted worms. About the aquatic plant Eichhornia crassipes, a total of 829 worms were sorted from it, which are related to six species of Naidinae , which are diaphanous , Ophidonais serpentine, Stylaria lacustris , Slavina appendiculata , N. variabilis and finally the species Allonais inaequalis. There was no any species of Pristininae sorted from this plant. The highest number of 467 individuals was recorded by the species Slavina appendiculata, with a percentage of 52.3% of the total number and 228 individual with a percentage of 25.5% was recorded by Allonais inaequalis.

Study of Naidid worms community associated with two species of aquatic plants in River Tigris inside Baghdad City / Iraq

The present study is concern with the interaction between the naidid worms diversity and the species of aquatic plant within which the worms found . For this purpose, two species of aquatic plant were used, Ceratophyllum demersum and Eichhornia crassipes. 12 samples of aquatic plants were collected , as one sample monthly for a period from September 2012 to September 2013 from different site on Tigris river within Baghdad City. From C. demersum, 1428 individuals, were sorted during the study period, related to 17 species. 12 species of subfamily Naidinae which are Chaetogaster limnaei , C. diastrophus , Ophidonais serpentine , Dero ( Dero) digitata. , D.(D.) evelinae , Nais pseudobtosa , N.simplex, N.stolci , N.Paradalis , N.elingius , N. variabilis and N. communis. In addition to five species of subfamily Pristininae, two species of Pristina , which are P. longiseta and . P. aequiseta, and three species of pristinella, which are P. . Jenkinae , P. sima , and P. osborni. Dero ( Dero) digitata was recorded the higher number of 430 individuals,with a percentage of 28.11% of the total sorted worms. About the aquatic plant Eichhornia crassipes, a total of 829 worms were sorted from it, which are related to six species of Naidinae , which are diaphanous , Ophidonais serpentine, Stylaria lacustris , Slavina appendiculata , N. variabilis and finally the species Allonais inaequalis. There was no any species of Pristininae sorted from this plant. The highest number of 467 individuals was recorded by the species Slavina appendiculata, with a percentage of 52.3% of the total number and 228 individual with a percentage of 25.5% was recorded by Allonais inaequalis.

Extraction and Determination of Triclocarban in Aquatic Plants by Homogenate Extraction Combined with HPLC-ESI-MS/MS

A specific, sensitive, and reliable analytical method involving homogenate extraction, solid phase extraction (SPE), and detection by high-performance liquid phase chromatography electrospray tandem mass spectrometry was developed in this study for the determination of triclocarban (TCC) in aquatic plants. Key factors that could affect the extraction, including the extraction solvent and its volume, the length of time of homogenate extraction, were examined and optimised. Under optimum conditions, the linearity of the method ranged from 0.2 ng/g to 200 ng/g, with correlation coefficients (r2) >0.999. The limit of detection was 0.05 ng/g, based on the ratio of the chromatographic signal to baseline noise (S/N = 3). Spiked recoveries of TCC in real aquatic plant samples ranged from 91.8% to 106.1%. The proposed method was successfully applied to analyse TCC in aquatic plant samples collected from a natural water environment.

Methods for simultaneous detection of the cyanotoxins BMAA, DABA, and anatoxin-a in environmental samples

Blue-green algae, also known as cyanobacteria, can produce several different groups of toxins in the environment including hepatotoxins (microcystins), neurotoxic non-protein amino acids β-methylamino-l-alanine (BMAA), and 2,4-diaminobutyric (DABA), as well as the bicyclic amine alkaloid anatoxin-a. Few studies have addressed the methods necessary for an accurate determination of cyanotoxins in environmental samples, and none have been published that can detect these cyanotoxins together in a single sample. Cyanotoxins occur in a wide range of environmental samples including water, fish, and aquatic plant samples. Using polymeric cation exchange solid phase extraction (SPE) coupled with liquid chromatography and fluorescence detection (HPLC/FD), and liquid chromatography ion trap tandem mass spectrometry (LC/MS/MS), these compounds can for the first time be simultaneously quantified in a variety of environmental sample types. The extraction method for biological samples can distinguish bound and free cyanotoxins. Detection limits for water ranged from 5 to 7 μg/L using HPLC/FD, while detection limits for and LC/MS were in the range of 0.8–3.2 μg/L.

Chemical Fractionation of Radionuclides and Stable Elements in Aquatic Plants of the Yenisei River

The Yenisei River is contaminated with artificial radionuclides released by one of the Russian nuclear plants. The aquatic plants growing in the radioactively contaminated parts of the river contain artificial radionuclides. The aim of the study was to investigate accumulation of artificial radionuclides and stable elements by submerged plants of the Yenisei River and estimate the strength of their binding to plant biomass by using a new sequential extraction scheme. The aquatic plants sampled were: Potamogeton lucens, Fontinalis antipyretica, and Batrachium kauffmanii. Gamma-spectrometric analysis of the samples of aquatic plants has revealed more than 20 radionuclides. We also investigated the chemical fractionation of radionuclides and stable elements in the biomass and rated radionuclides and stable elements based on their distribution in biomass. The greatest number of radionuclides strongly bound to biomass cell structures was found for Potamogeton lucens and the smallest for Batrachium kauffmanii. For Fontinalis antipyretica, the number of distribution patterns that were similar for both radioactive isotopes and their stable counterparts was greater than for the other studied species. The transuranic elements (239)Np and (241)Am were found in the intracellular fraction of the biomass, and this suggested their active accumulation by the plants.

Latest developments and opportunities for 3D analysis of biological samples by confocal μ-XRF

X-ray fluorescence analysis performed with a primary radiation focused in the micrometer range is known as micro-X-ray fluorescence (μ-XRF). It is characterized by a penetration depth higher than other micro-analytical methods, reaching hundreds of micrometers in biological samples. This characteristic of the X-ray beam can be employed in 3D analysis. An innovative method to perform 3D analysis by μ-XRF is the so-called confocal setup. The confocal setup consists of X-ray lenses in the excitation as well as in the detection channel. In this configuration, a micro-volume defined by the overlap of the foci of both X-ray lenses is analyzed. Scanning this micro-volume through the sample can be used to perform a study in three dimensions. At present, X-ray lenses used in confocal μ-XRF experiments are mainly glass capillaries and polycapillaries. Glass capillaries are used in the excitation channel with sources of high photon flux like synchrotron radiation. Half polycapillaries or conical polycapillary concentrators are used almost exclusively in the detection channel. Spatial resolution of the confocal μ-XRF depends on the dimensions of the foci of both X-ray lenses. The overlap of these foci forms an ellipsoid which is the probing volume of the confocal setup. The axis length of the probing volume reported in confocal μ-XRF experiments are of order of few tens of micrometer. In our confocal setup, we used a commercial glass monocapillary in the excitation channel and a monolithic half polycapillary in the detection channel. The polycapillary was home-made by means of drawing of multibundles of glass capillaries in a heating furnace. The experiment was carried out at the beamline D09B-XRF of the Synchrotron Light National Laboratory (Laboratório Nacional de Luz Síncrotron, LNLS) using white beam. A model for the theoretical description of X-ray fluorescence intensity registered by confocal μ-XRF was introduced by Malzer and Kanngieβer [2005. A model for the confocal volume of 3D micro-X-ray fluorescence spectrometer. Spectrochim. Acta B 60, 1334–1341]. These authors showed that the measured scanning of fluorescent intensity is the spatial convolution of the sensitivity and the X-ray fluorescence emission rate detected. In a previous work we demonstrated that the convolution theorem can simplify the calibration and quantification process in confocal μ-XRF. In the present work, we applied these ideas to analyze samples of aquatic plants and a sample of tooth by confocal μ-XRF. We showed that confocal μ-XRF can be successfully applied to help the study of the effects of water bioremediation on aquatic plants. We also showed that confocal μ-XRF can be used to make topological studies of teeth.

Actinides and other radionuclides in sediments and submerged plants of the Yenisei River

The source of radioactive contamination of the Yenisei River floodplain, including contamination with actinides, is the Mining-and-Chemical combine (MCC), which has for many years been producing weapons-grade plutonium. Actinides have been detected not only in the soil and sediment of the river but also in the biomass of aquatic plants. The aim of our investigation was to assess the levels of actinides and other radionuclides in sediments and aquatic plants both near the MCC and at a considerable distance from it, down the Yenisei River. Investigations of the Yenisei River sediment samples revealed high activity concentrations of actinides (Pu isotopes and 241Am), which were 100 times higher than their global fallout levels. Sequential extraction of radionuclides from samples of sediments collected near the MCC showed that the amounts of extracted 241Am were the largest (up to 98% of initial activity). It was found that aquatic plants of the Yenisei River collected both near the MCC discharge site and at a distance up to 200 km downstream contained several actinide isotopes. The aquatic moss, Fontinalis antipyretica, was found to contain higher levels of radionuclides than Potamogeton lucens. Leaves of P. lucens contained higher levels of radionuclides, including 239Np, than stems. Sequential extraction of radionuclides from samples of aquatic plants showed that 239Np levels in exchangeable and adsorption fractions of P. lucens biomass were higher than in the respective fractions of F. antipyretica biomass.

Radiocarbon Chronologies of Holocene Lacustrine Sediments from the Southern Coast of Buenos Aires Province, Argentina

Two lacustrine sediment sequences, La Olla 1 and Laguna del Sauce Grande, on the southern coast of Buenos Aires Province, Argentina, were investigated for carbon reservoir effects, which may influence age-depth chronologies. Fruits of the submerged macrophyte Ruppia cf. maritima from the La Olla 1 sequence, and gastropod shells of Heleobia parchappii from the Laguna del Sauce Grande core, were radiocarbon dated. In addition, terrestrial plant remains and shells of living specimens were dated to assess the presence and magnitude of a reservoir effect. A reservoir age of about 800 14C yr is estimated for the aquatic plant samples of La Olla 1 for the early Holocene. The reservoir effect is attributed to the in wash of 14C-deficient bicarbonate from the surrounding sand dunes. The decay of marine organisms and salt spray are likely the main sources of 14C-deficient carbon. The magnitude of the reservoir effect is consistent with marine reservoir offsets reported for the region. The 14C measurements on shells of living and fossil specimens of Heleobia parchappii indicate the absence of a reservoir effect at Laguna del Sauce Grande, which may be due to the large size and shallow nature of the lake. This study shows how the reservoir ages of 2 close-by lakes in very similar geological settings can be largely different. These results have significant implications for the interpretation of 14C dates from lacustrine deposits in the region.