Sediment Reference Samples Research Articles

Platinum Nanoparticle Extraction, Quantification, and Characterization in Sediments by Single-Particle Inductively Coupled Plasma Time-of-Flight Mass Spectrometry.

Particulate emissions from vehicle exhaust catalysts are the primary contributors to platinum group elements (PGEs) being released into roadside environments, especially platinum (Pt) particles. With increasing traffic density, it is essential to quantify the emission, accumulation, and potential health effects of traffic-emitted Pt particles. In this study, three procedures were investigated to extract Pt nanoparticles (NPs) from sediments and characterize them by single-particle inductively coupled plasma time-of-flight mass spectrometry (spICP-TOF-MS). For this purpose, a reference sediment sample was spiked with manufactured Pt NPs. Pt NPs’ extraction recoveries reached from 50% up to 102%, depending on the extraction procedure and whether the particle mass or number was used as the metric. Between 17% and 35% of the Pt NPs were found as unassociated Pt NPs and between 31% and 78% as Pt NPs hetero-aggregated with other sediment particles. Multi-elemental analysis of Pt-containing NPs in the pristine sediment revealed frequently co-occurring elements such as Au, Bi, and Ir, which can be used to determine a natural background baseline. Our results demonstrated that spICP-TOF-MS elemental characterization allows for distinguishing anthropogenic Pt NPs from the natural background. In the future, this could enable the sensitive monitoring of PGE release from anthropogenic sources such as vehicle exhausts.

The assessment of particle selection and blank correction to enhance the analysis of microplastics with Raman microspectroscopy

Although microplastics research has received enormous attention in the last decade, both the research practices and the quality of produced data should still be improved. In this study, the identification process of microplastics with Raman imaging microscope was improved by decreasing the time needed for the analysis. To do that, new features, including terrain mosaic and automatic particle selection, were utilized and various ways of handling the produced microplastics data were implemented and discussed. Furthermore, blank correction of microplastic concentrations was demonstrated and its effects on the recovery of spiked microplastics was assessed with aqueous and solid samples.Six types of microplastics, including fragments and fibers, were spiked in triplicates of ultra-pure water and reference sediment samples. The spiked samples were pretreated by a modified method of the universal enzymatic purification protocol. Microplastics were analyzed with Raman imaging microscope, using terrain mosaic combined with automatic particle selection. The microplastics data were subjected to different identification steps to estimate the potential overestimation and underestimation of microplastics counts.With the complete correction of Raman-based data, the average recovery rates of fragments (77–80%) were higher than fibers (20–33%). The decrease in recovery rates of spiked microplastics (49–57%) were observed when blank correction was applied (28–47%). The impact of the blank correction depended on the polymer, causing exclusion of PE, PET, and PP from sediment samples. For the completely corrected Raman-based data, the average recovery rates of microplastics were higher for water than sediment samples both with and without blank correction.The results demonstrated the impact of blank correction on the microplastics recovery rates. To our knowledge, this is the first study to explore the use of automatic particle selection of Raman imaging microscope for microplastics analysis. Hence, potential drawbacks and advantages of the new features of Raman imaging microscope were explicitly discussed.

Simultaneous Determination of Fluorine and Chlorine in Marine and Stream Sediment by Ion Chromatography Combined with Alkaline Digestion in a Bomb

Fluorine and chlorine are important tracers for geochemical and environmental studies. In this study, a rapid alkaline digestion (NaOH) method for the simultaneous determination of fluorine and chlorine in marine and stream sediment reference samples using ion chromatography is developed. The proposed method suppresses the volatilization loss of fluorine and chlorine and decreases the matrix effects. The results are in good agreement with fluorine ~100%, chlorine ranging from 90 to 95% of the expected concentrations. The detection limits of this method were 0.05 μg/g for fluorine and 0.10 μg/g for chlorine. This method is simple, economical, precise and accurate, which shows great potential for the rapid simultaneous determination of fluorine and chlorine in large batches of geological and environmental samples commonly analyzed for environmental geochemistry studies.

A simple, selective and eco-friendly method for quantification of polychlorinated biphenyls in sediment samples at ultra-trace levels by headspace solid-phase microextraction-gas chromatography-ion trap tandem mass spectrometry

ABSTRACT An analytical method based on headspace solid-phase microextraction gas chromatography- ion trap tandem mass spectrometry (HS-SPME-GC-ITMS/MS) was optimised and developed for estimating 20 predominant polychlorinated biphenyl (PCB) concentrations in sediment samples. The effect of experimental parameters involving fibre materials, amount of water added, temperature effect, sorption time, stirring effect, and the addition of solvents were examined with gas chromatography-electron capture detector (GC-ECD). The analytical performance of association of HS-SPME-GC-ITMS/MS proposed methodology was examined by spiked sediment with the selected PCB congeners. The repeatability and reproducibility of measurements (n = 6), expressed with relative standard deviation (RSD), was below 13% and 16%, respectively. Good linearity was observed within the concentration range studied and the LODs were between 0.02 and 0.82 ng g−1. Accuracy was assessed by analysing a reference sediment sample with certified concentrations of several PCBs. Standard addition calibrations were done and concentrations of PCBs with the proposed method were in good agreement with the certified PCB concentrations. The method was also efficiently applied to real sample sediment from Bizerte Harbour, revealing the existence of several congeners at level less than 1.1 ng g−1. These obtained results were also on concordance with analysis of this real sample using a conventional soxhlet extraction method. The developed procedure is highly effective and selective, free of organic solvents, relatively simple and fast, and become a suitable alternative for routine monitoring of residues of PCB from sediments at ultra-trace levels.

Characterizing algal microbiomes using long-read nanopore sequencing

Microbes are vitally important for seaweed growth, functioning and reproduction, and are likely to have a big impact on aquaculture. Algae-associated bacteria, however, remain mostly unmonitored in aquaculture. Here, we studied the microbiomes of Ulva australis and Ulva lacinulata, three natural populations and an aquaculture set-up, based on full-length 16S rRNA gene sequences. The microbiome of cultivated Ulva was pronouncedly different from natural populations, and was specifically associated with higher relative abundances of known growth-promoting bacteria Sulfitobacter and Roseobacter. On a smaller scale, there were species-specific differences as well. In general, Ulva-associated communities were highly distinct from environmental seawater and sediment reference samples. We demonstrated a workflow generating full-length 16S rRNA sequences in real-time using Oxford Nanopore sequencing. We compared 3 different reference databases to assign taxonomy with Kraken2 (SILVA, Greengenes and NCBI). In addition, we used Nanopore's cloud-based EPI2ME workflow for comparison. All four methods yielded comparable results in terms of relative abundances on phylum and order level, but differed widely in alpha diversity indices at genus level. Using the NCBI 16S database, especially in combination with the EPI2ME workflow, resulted in a high proportion of false identifications of cyanobacteria due to chloroplast contamination. Based on our results, we recommend assigning taxonomy of Nanopore-derived long-reads with Kraken2 and the SILVA database in seaweed-microbiome studies. The protocols used in this study provide results within 24 h and may be applicable for rapid microbial surveys in aquaculture.

Geochemical and molecular characteristics of ferromanganese deposits and surrounding sediments in the Mariana Trench: An Implication for the geochemical Mn cycle in sedimentary environments of the trench zone

Trench systems are some of the most important geodynamic settings on Earth and have a substantial influence on the global metal cycle. Trench environments are affected not only by episodic deposition of volcanic ash, but also exhibit a continuous water–rock chemical exchange. Ferromanganese nodules, which are archives for the marine Mn cycle, were first discovered in the southern Mariana Trench during China’s major 10,000-meter hadal trench scientific expedition in 2016. Nevertheless, their geochemical characteristics and formation mechanism in sedimentary environments of the trench zone remain enigmatic. In this study, these ferromanganese nodules and surrounding sediments were examined by geochemical and microbial methods. Bulk geochemistry indicated that trench nodules are characterized by high Mn/Fe ratios and nodule textures indicate a rapid growth rate, with Mn mainly from two sources: volcanic ash alteration and fluids discharge from the trench seabed. High-resolution in situ geochemical analysis categorized microlayers of an individual nodule into three types. Type I is the interior part that has a high Mn/Fe ratio (>20) and high growth rate (52.19–3571.73 mm/Myr), and formed by the influence of fluid discharge activities around this region. Type II is laminae from the exterior part that have a hydrogenetic origin with lower Mn/Fe ratio (0.01–2.50) and lower growth rate (4.54–9.86 mm/Myr). Type III is laminae from the exterior part that have a diagenetic origin with moderately high Mn/Fe ratio (2.5–15.0) and moderately high growth rate (12.40–18.93 mm/Myr). 16S rRNA gene sequence analysis revealed that the bacterial community structures in the nodule-bearing sediment samples, dominated by Shewanella and Colwellia, were substantially different from those of reference sediment samples. For the first time, we propose a conceptual model for a geochemical Mn cycle and nodule formation in trench sedimentary environments using both geochemical and microbial data.

Use of ecotoxicity assessment for determining reusability of treated marine sediment on terrestrial land

Contaminated marine sediment can be treated to satisfy the concentration-based chemical criteria, but the treated sediment could still not be appropriate for reuse. This study used ecotoxicity tests to determine the reusability of treated marine sediment on terrestrial land. Changes in the toxicity of sediment contaminated with a mixture of total petroleum hydrocarbons (TPH) and heavy metals after treatment were investigated using both terrestrial (earthworm and wheat) and aquatic organisms (Daphnia magna, Allivibrio fischeri). The contaminant concentrations were reduced to meet the remedial goal of this study. As a result, the toxic effects on the tested organisms were reduced. The toxic effects of the reference sediment sample (RSS) that represents the background sediment toxicity were greater on wheat and earthworms than the treated sediment samples (TSSs). This was attributed to factors such as salinity and sediment texture. By comparing the toxicities of the sediment samples with that of the RSS, it was found that not only the contaminant concentrations, but also the sediment physicochemical properties such as pH, salinity, particle size distribution, and nutrient contents need to be considered from the step when the treatment processes are selected. In conclusion, different aspects of the treated marine sediment quality, apart from the level of contaminants regulated, could be tested using ecotoxicity tests to determine the reusability of the treated marine sediment on land.

Heavy metal accumulation and distribution in Phragmites australis seedlings tissues originating from natural and urban catchment.

The retention of heavy metal (HM) was studied in root and rhizomes (BLG), stems (ST), and leaves (LF) of Phragmites australis (common reed) seedlings collected from different locations, differing in the scale of anthropogenic interference. The analysis includes the reference samples of sediments in uncontaminated lake Garczonki and contaminated roadside ditch in Cieplewo. The concentrations of Zn, Cu, Pb, Cd, Ni, and Cr were analyzed in plant tissues and sediments using the atomic absorption spectrometry and inductively coupled plasma mass spectrometry. The general assessment of sediments collected in the Garczonki lake showed a good environmental status; while in the roadside ditch in Cieplewo, the sediments were considerably polluted with HM. In the first stage of plant growth, all of the analyzed HMs are mainly inhibited by BLG system. The decreasing trend of elements was as follows: BLG > ST > LF. The organs followed different decreasing trends of HM concentration; the trend Zn > Cu > Ni > Cr > Pb > Cd was found in ST and LF for the Garczonki lake seedlings and for BLG and LF for the roadside ditch in Cieplewo seedlings. Zn showed the highest concentration, while Cd the lowest concentration in each of the examined organs. The bioaccumulation factor indicated the higher mobility of HM in seedlings in the Garczonki lake than in the roadside ditch in Cieplewo. The morphological studies suggest the good state and health of seedling from both sites; however, the reduction of root hair surface was observed for the roadside ditch seedlings. The anatomical studies present changes in the size of the nucleus and count of chloroplasts in LF. No reaction on HM contamination sediments in the seedlings from the roadside ditch in Cieplewo in the aerenchyma was noted. Potentially, both types of seedlings can be used to decontaminate environments rich in HM. However, the level of HM absorbed by seedlings (in the first stage of growth) should be considered due to the behavior in the target phytoremediation site.

Photochemical Vapor Generation of Tellurium: Synergistic Effect from Ferric Ion and Nano-TiO2.

Photochemical vapor generation (PVG) is emerging as a promising analytical tool for Te determination, thanks to its efficient matrix separation, and simple and green procedure. However, the low PVG generation efficiency of Te is the bottleneck for its wide application in environmental samples containing trace Te. Herein, we reported a high efficient PVG for Te determination by synergistic effect of ferric ion and nano-TiO2. The analytical sensitivity was enhanced approximately 15-fold for Te(IV) in the presence of both ferric ions and nano-TiO2, comparing to conventional PVG. Besides, the use of nano-TiO2 can provide Te(VI) and Te(IV) an equal and high PVG efficiency in the presence of ferric ions, owned to the high photocatalytic performance of TiO2 under short-wavelength UV irradiation (254 and 185 nm). Under the optimized experimental conditions, a detection limit of 1.0 ng L-1 was obtained. The precision of replicate measurements was 2.3% (RSD, n = 7) at 0.5 μg L-1 for Te(IV). The methodology was validated by successful determination of Te in surface waters and two standard reference sediment samples. To our best knowledge, this is the first report of the synergistic enhancement of transitional metal ions and nano-TiO2 in PVG, which possesses potential for highly sensitive determination of vapor-forming elements.

Determination of Lanthanides in Soil and Sediment Reference Samples by ICP-MS: Comparison of Fusion and Acid Digestion Methods

Determination of Lanthanides in Soil and Sediment Reference Samples by ICP-MS: Comparison of Fusion and Acid Digestion Methods

The effects of mariculture on heavy metal distribution in sediments and cultured fish around the Pearl River Delta region, south China

Thirty-six sediment samples were collected from six mariculture sites and corresponding reference sites (approximately 200–300 m away from each mariculture site) to study the effects of mariculture on heavy metal: copper (Cu), zinc (Zn), chromium (Cr) and lead (Pb) distribution in sediments and cultured fish around the Pearl River Delta region, south China. The mean concentrations of Cu, Zn, Cr and Pb in all mariculture sediment samples were 109, 273, 99 and 33 mg/kg, compared with 63, 209, 56 and 23 mg/kg for reference sediment samples, respectively. The Pollution Load Index of sediment for each site was over 1, implying substantial heavy metal pollution. The results of principal component analysis and hierarchical clustering analysis indicate that marine aquaculture activities have enriched the surface sediments underneath mariculture rafts with Cu, Zn and Pb, possibly due to the accumulation of unconsumed fish feeds, fish excreta and antifouling paints (except Cr). Two kinds of fish feeds, feed pellets and trash fish commonly used in Hong Kong were analyzed. The concentrations of Zn and Cu contained in feed pellets were significantly higher (p < 0.05) than in trash fish due to addition of these elements as growth promoters during pellet production. However, the Pb content in trash fish (due to contamination) was significantly higher (p < 0.05) than in feed pellets. Three cultured fish species, namely red snapper (Lutjanus campechanus), orange-spotted grouper (Epinephelus coioides) and snubnose pompano (Trachinotus blochii), were collected from each mariculture site for metal analysis. Lead concentrations in 21 fish samples exceeded the Chinese safety guideline (0.5 mg/kg, GB18406.4–2001), indicating that Pb contamination in cultured fish would be a public health concern.

Exposure Experiments of Geochemical Reference Samples to CO2-satureted Seawater

We investigated interactions between geochemical reference samples and CO2-saturagted seawater. The experiments were made under normal temperature and atmospheric pressure. We used the reference samples of igneous rocks, sedimentary rocks, sediments and terrestrial soil, issued from the Geological Survey of Japan (AIST). Chemical parameters in the seawater reacted with rock/sediment samples were determined. The results of quantitative analysis of by ICP-AES showed that calcium was released from coral, dolomite and limestone due to the dissolution of calcium carbonate in seawater acidified by CO2. Significant changes of other elements were not detected for all samples. The results of nutrient analysis showed that phosphate was eluted from dolomite, slate, coastal marine sediment and pelagic marine sediment significantly. Significant concentration of nitrate and nitrite were not detected except in the seawater reacted with terrestrial soil. On the other hand, concentrations of ammonia increased in the seawater reacted with slate, coastal marine sediment, pelagic marine sediment and terrestrial soil. Dissolved inorganic carbon (DIC) and total alkalinity (TA) were clearly increased in the seawater reacted with coral, dolomite, limestone. As above, increases of calcium were also detected in these samples, suggesting dissolution of calcium carbonate to the seawater acidified by CO2. Increase of DIC and TA in the coral sample are corresponded to the changes of partial pressure of CO2 (pCO2) in the seawater from 83% to 49% and pH from 4.8 to 6.1.

機器中性子放射化分析法による海底質標準試料(JMS-1, JMS-2及びJMS-3) 中の微量元素の定量

機器中性子放射化分析法による海底質標準試料(JMS-1, JMS-2及びJMS-3) 中の微量元素の定量

Study of application of BCR sequential extraction procedure for fractionation of heavy metal content of soils, sediments, and gravitation dusts

This article deals with the application of original and modified Community Bureau of Reference (BCR) sequential extraction scheme for fractionation of contaminant metallic elements (Zn, Cd, Pb, Ni, Cr, and Cu) in sediments, soils, and aerial gravitation dusts. Contamination level and extractability of contaminant element in our internal laboratory soil, sediment, and gravitation dust reference samples was studied by original BCR procedure proposed to certified reference material (CRM) 601 sediment reference material. A preliminary comparative study was performed to control the extraction ability of original and modified BCR procedure using CRM 601 and 701, respectively. It was established that original BCR scheme can be applied for different kinds of samples (sediment, soil, dust) when necessary sample amount is available; however, one has to calculate with analyte losses due to pH instability during the second and third leaching steps and readsorption may occur after third leaching step during the phase separation. This latter observation was verified by direct solid sample analysis of original samples and third-step solid residue.

A particle separator used to concentrate Dinoflagellate cysts from sediment

A device has been developed to separate and collect large numbers of dinoflagellate cysts from sediment samples of several liters volume. The apparatus consists of a 152.5 × 44.5 × 38‐cm fiberglass tank with a 20‐µm screen inserted diagonally across the long dimension, creating an inclined plane as the bottom of a settling tank. A peristaltic pump delivers resuspended bottom material to the top of the deep end of the tank. The particles settle according to mass and friction as the water moves to a drain near the top center of the shallow end of the screen. The desired particles can be vacuumed from specific areas of the screen and further refined with a final sieving step. More than 16 L marine mud were processed in this apparatus at one time. In a reference sediment sample collected from beneath New Haven Harbor (Connecticut, USA), cyst recovery was 25% for living cysts. The sediment in the uppermost part of the sorter had approximately 376 times more cysts/mL than the sediment originally added. The cyst fraction (particles 20‐100 µm) contained ten times more cysts in the uppermost part of the sorter than at the middle or lower ends. Cysts within the cyst‐rich zone of the separator settled differently depending upon species, size, and morphology.

Toxicity of Reference Sediment Samples

This study was done to determine toxicity of certified reference sediment to be used for quality assurance in sediment toxicity testing program. Certified Reference Harbor Sediment (HS-4B for PAHs) and Estuarine Sediment (LGC-6137 for Trace Metals) were procured commercially from LGC Company, UK, and repeatedly analyzed against solid phase Microtox toxicity assay to determine EC50 values. Both PAHs rich and trace metals rich sediments were very toxic to Microtox with EC50 405 mg L-1 and 554 mg L-1 respectively. Solvent extraction resulted in a drastic decrease in the toxicity of PAHs rich reference sediment sample but in trace metal rich sediment the decrease in the toxicity was marginal. The certified reference sediments with the availability of toxicity data can be incorporated for quality assurance as controls in Microtox toxicity determination of field samples of unknown toxicity.

Toxicity of estuarine sediments using a full life-cycle bioassay with the marine copepod Robertsonia propinqua

Estuarine sediment contamination is a growing significant ecological issue in New Zealand. Methods of assessing toxicity and ecological impacts in a cost effective way are currently limited. Further to that is a need to develop bioassays that generate data quickly and cost effectively and have ecological relevance to the wider community. A chronic full life-cycle bioassay to assess the toxicity of New Zealand estuarine sediments using the marine harpacticoid copepod Robertsonia propinqua has been investigated. Sediment samples were collected from the Bay of Plenty region and included two polluted and one reference site. Sources of pollutants in the contaminated field sites originated from a variety of sources and generally include nutrients, pesticides and herbicides and the pollutants zinc, copper, lead and polycyclic aromatic hydrocarbons (PAHs). Conversely, the reference site was exposed to low levels of contaminants due to the relatively undeveloped catchment. Adult male and female copepods were exposed to field collected sediments for 24 days under flow-through conditions at 21 °C and 12 h L:D cycles. Five endpoints were recorded: male and female survival, fecundity (number of gravid females per replicate at the end of the test), clutch size per female, number of eggs per sample and juvenile survival (number of nauplii and copepodites per replicate at the end of the test). Adult mortality was observed in all sediment samples but the number of males, gravid females, clutch size per female and number of eggs produced were not affected by either the contaminated or reference sediment samples. However, the contaminated sediments did reduce reproductive output (i.e. nauplii and copepodite production). Therefore, we conclude that reproductive endpoints provide a good measure of sediment-associated contaminant effects compared with adult R. propinqua survivorship. It may be that a change in focus from chemical thresholds without ecological relevance or lethal dose threshold methods, to more subtle but ecologically significant elements of faunal life, such as reproductive success, are a more sensitive and a long term ecologically informative method.

Determination of Trace Elements (Ag, B, Ge, Mo, Sn, W, Tl) in Reference Samples of Soils and Bottom Sediments by Atomic Emission Spectrometry: A Traceability and Fitness‐for‐Purpose Study

Reference samples of soils from the Institute of Applied Physics, Irkutsk (RIAP), the Institute of Geochemistry, Irkutsk (IGI) and the United States Geological Survey, Reston (USGS) were analysed with the aim of determining Ag, B, Ge, Mo, Sn, Tl and W abundances by an atomic emission method with air‐stabilised D.C. arc excitation. Two series of reference samples of soils and bottom sediments, GSS‐1‐8 and GSD‐1‐12 (IGGE), were used to ensure the traceability link for the analytical results. Traceability was also demonstrated through the comparison of measured results by AES and ICP‐MS methods. It is shown that the reference samples GSS‐1‐8 and GSD‐1‐12 satisfied the “fitness‐for‐purpose” criterion (uncertainty U of the certified value should be one‐third to one‐tenth the magnitude of routine laboratory data uncertainty S (S/U &gt; 3‐10)) and can be applied for calibrating AES techniques.

A modified method for biogenic silica determination

We describe a modified method for the determination of biogenic silica (BSi) in lacustrine sediment samples with BSi concentrations >0.5% SiO2 (detection limit). To speed up the leaching procedure (48 samples per day), we suggest the use of Teflon autoclaves that can be left unattended (no stirring of the solution) for 3 h at 100°C in an oven. We suggest a volume correction by Na measurement to account for volume errors during pipetting off a hot solution. We also propose to carry out a correction for minerogenic silica by the simultaneous determination of Al in the leachate. Analytical precision and accuracy of the proposed method are 2.4% (relative standard deviation) and 70–110% recovery (relative to the mean of four international reference sediment samples), respectively. Additionally, we demonstrate that pre-treatment of the samples with H2O2 and/or HCl prior to alkaline leaching is not necessary for all samples. Due to the great diversity of lacustrine and marine sediments, however, the pre-treatment procedure should be tailored for samples from different sites.

Rapid screening of polychlorinated biphenyls in sediments using non-equilibrium solid-phase microextraction and fast gas chromatography with electron-capture detection

A rapid method for the screening of polychlorinated biphenyls (PCBs) in sediment samples is described. Analytes are concentrated on a poly(dimethylsiloxane) (PDMS) solid-phase microextraction (SPME) fibre, separated using a narrow-bore gas chromatography column (10 m × 0.1 mm I.D.) and determined with a micro-electron-capture detector (micro-ECD). The narrow-bore column showed a similar separation efficiency to a conventional capillary one (30 m × 0.32 mm I.D.) and allowed a 3 times reduction in the analysis time. Moreover, thermal desorption of SPME fibres in the narrow-bore column did not produce any degradation in the quality of separations when compared to the split injection mode. The use of an oxidative sample treatment was mandatory to remove sulphur interferences in the chromatograms and increase the yield of PCBs during SPME for short sampling times. Under optimised conditions, a fraction of sediment (0.1–0.5 g) was mixed with 5 ml of a 0.2 M potassium permanganate solution and 0.5 ml of sulphuric acid 6 M in a 22 ml closed vessel. Sample treatment and headspace SPME of PCBs were performed simultaneously for 10 min at 100 °C. Globally, the whole analytical procedure takes about 20 min and presents quantification limits between 0.5 and 1.3 ng/g. Accuracy was evaluated by analysing a reference sediment sample with certified concentrations of several PCBs.