Range Of Nd Research Articles

Occurrence, source, and transfer fluxes of organophosphate esters in the South Pacific and Fildes Peninsula, Antarctic

Concentrations of 11 organophosphate esters (OPEs) were investigated in surface water and atmosphere samples collected from the South Pacific and Fildes Peninsula. TEHP and TCEP were the dominant OPEs in South Pacific dissolved water, with concentration range of nd–106.13 ng/L and 1.06–28.97 ng/L, respectively. The total concentration of ∑10OPEs in the South Pacific atmosphere was higher than that in Fildes Peninsula, ranging from 216.78 to 2033.97 pg/m3 and 161.83 pg/m3, respectively. TCEP and TCPP were the most dominant OPEs in the South Pacific atmosphere, while TPhP was the most prevalent in the Fildes Peninsula. The air-water exchange flux of ∑10OPEs at the South Pacific was 0.04–3.56 ng/m2/day, with a transmission direction of evaporation totally determined by TiBP and TnBP. The atmospheric dry deposition dominated the transport direction of OPEs between air and water, with an flux of Σ10OPEs at 10.28–213.62 ng/m2/day (mean: 85.2 ng/m2/day). The current transport flux of OPEs through the Tasman Sea to the ACC (2.65 × 104 kg/day) was significantly higher than the dry deposition flux over the Tasman Sea(493.55 kg/day), indicating the Tasman Sea's importance as a transport pathway for OPEs from low latitude areas to the South Pacific. Principal component analysis and air mass back-trajectory analysis provided evidence of terrestrial inputs from human activities that have impacted the environment in the South Pacific and the Antarctic.

The Spatial Distribution and Potential Risk Assessment of POPs in Farmland around a Typical E-Waste Dismantling Site.

Pollution from electronic-waste (E-waste) dismantling is of great concern. This study investigated the concentrations of polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and polybrominated diphenyl ethers (PBDEs) in 253 cropland soil samples around an abandoned E-waste dismantling site in Taizhou city, Zhejiang province in China, using an analytical method which simultaneously extracted, purified and determined the identity and quantity of the three types of persistent organic pollutants. Meanwhile, their spatial distributions, pollution characteristics, and risk assessments were further analyzed. Total PCBs in the test soils ranged from below method detection limits (ND) to 2985.25μgkg-1 on a dry weight basis (d.w.), and the spatial distribution indicated a "hot spot" of PCBs pollution in the study area. The PAHs were detected in all samples with total concentrations ranging from 4.99 to 2723.06μgkg-1d.w. The distribution of PBDEs showed the pollution characteristics of "family-run workshops", with a total content range of ND ~ 899.34μgkg-1d.w., of which BDE209 was typically the dominant congener, accounting for 74.05% of the total PBDEs content in the test soils, with the highest content reaching 857.72μgkg-1d.w. Results showed that the ecological and lifetime carcinogenic risks of PCBs and PAHs were low in the study area, but the health risk caused by oral ingestion and dermal contact accounted for the highest proportion of the total exposure risks, while inhalation could be ignored. PBDEs in soils of the study area were a potential chronic non-carcinogenic risk, particularly for children. Therefore, in order to protect human health and environment, it is necessary to regulate the management of E-waste dismantling sites and pollution control.

EXTRACTION OF LIGHT GROUP LANTHANIDE NITRATES BY A BINARY EXTRACTANT BASED ON DI-(2-ETHYLHEXYL)PHOSPHORIC ACID AND TRIOCTYLAMINE

The process of extracting the light group lanthanide nitrates from neutral aqueous solutions with a binary extractant based on di-(2-ethylhexyl)phosphoric acid (HA), tri-n-octylamine (NR3) and solvating additive of tri-n-octylamine nitrate in a non-polar organic diluent was investigated in this study. Using neodymium nitrate as an example, it was shown that this extractant (NR3HA+NR3HNO3) extracts Ln(NO3)3 according to the laws of binary extraction. The cation and anion of the inorganic salt pass into the organic phase in a stoichiometric ratio. The extraction isotherms of lanthanide nitrates are S shape, and only slight variation of pH is observed during the extraction. Based on the study of the absorption spectra of Nd complexes in the organic phase, it was found that at low concentration the Nd form a complex (NdA3)•NR3HNO3, and at a high concentration of Nd (when the extraction is saturated), a compound of the composition (NdA2NO3)•NR3HNO3 is formed. The introduction of salting-out agents in the aqueous phase or the organic phase makes it possible to vary the distribution coefficients (DNd). With an increase in the concentration of sodium nitrate in the aqueous phase, DNd increases, and with an increase in the concentration of NR3HNO3, it correspondingly decreases. The introduction of the salting-out and solvating agent NR3HNO3 into the organic phase eliminates the formation of precipitation in the organic phase during the extraction of lanthanide nitrates. Quantitatively, the Nd extraction process in a wide range of Nd(NO3)3 concentrations and extractant compositions can be described on the basis of two coupled binary extraction equations and the corresponding concentration constants. It has been established that the proposed extractant provides high separation factors for neodymium and other light group lanthanides.

Gold nanoparticle‐carbon nanotube nanohybrids with peroxidase‐like activity for the highly‐sensitive immunoassay of kanamycin in milk

SummaryOwing to the increasing incidences of antibiotic residues being found in foods of animal‐origin, rapid and reliable screening methods for detecting these residues are urgently required. This study aimed to develop a robust and ultrasensitive colorimetric immunoassay based on nanohybrids for the rapid screening of kanamycin (KAN) residues in milk. The HAuCl4 solution was directly reduced on the multiwalled carbon nanotubes (MWCNTs) using a one‐step synthesis method to obtain the Au/MWCNTs nanohybrids. The Au/MWCNTs exhibited mimetic peroxidase activity and higher affinities for the TMB and H2O2 compared with horseradish peroxidase and other nanohybrids. A direct competitive enzyme‐linked immunosorbent assay (dcELISA) based on Au/MWCNTs was developed and employed for KAN detection in milk samples under optimised conditions. The dcELISA showed high sensitivity toward KAN residues, with a detection limit of 11.2 pg/mL. Moreover, this novel immunoassay displayed high precision and accuracy in milk samples, with a recovery rate ranging from 94.3 to 124.5% and a coefficient variation from 7.8 to 11.3%. Eight real milk samples were found to contain a KAN concentration in the range of ND–0.26 ng/mL. Therefore, this dcELISA based on the Au/MWCNTs nanohybrid has promising potential for applications in food monitoring and quality control.

Suspect and nontarget screening of known and unknown organophosphate esters (OPEs) in soil samples

Ninety-five soil samples (n = 95) were analyzed using an integrated suspect and non-target organophosphate ester (OPE) screening strategy. This suspect and non-target screening strategy allowed us to fully or tentatively identify 26 OPEs or OPE-like substances. Among these 26 newly identified contaminants, bisphenol A bis(diphenylphosphate) (BPABDP) exhibited the highest detection frequency of 83.2 %, with a concentration range of ND - 385 ng/g dry weight (dw). We also observed that BPABDP was significantly correlated with all other OPEs (p < 0.001 in all pairs), suggesting that BPABDP is widely used as a plasticizer and flame retardant in various commercial products. Another interesting finding was the discovery of four novel OPE structures with tentatively proposed chemical structures. Among these four non-target OPEs, (tert-butyl) phenyl bis(2,4-di-tert-butylphenyl) phosphate (TBPBDTBPP) shared a backbone structure very similar to that of the well-known OPE, tris(2,4-di-tert-butylphenyl) phosphate (TDTBPP). Detection frequency of this newly discovered OPE was high, up to 69.5 %, and it was significantly correlated with isodecyl diphenyl phosphate (IDDP), BPABDP, diphenyl 2-isopropylphenyl phosphate (2IPPDPP), and tricresyl phosphate (TCrP, p < 0.05 in all pairs), respectively. This study reported the most comprehensive suite of OPEs in soil samples, and 16 out of them were recognized in soil for the first time.

Changes and release risk of typical pharmaceuticals and personal care products in sewage sludge during hydrothermal carbonization process

Hydrochars were obtained by hydrothermal carbonization treatment of municipal sewage sludge. Effects of reaction temperature (180–300 °C) and reaction time (2–15 h) on structural characteristics of the hydrochars, and changes and release risk of typical pharmaceuticals and personal care products (PPCPs) in the hydrochars were investigated. Reaction temperature played a more important role than reaction time on hydrochar properties and decarboxylation reaction was the primary process during the converting of sludge to hydrochars. The sludge hydrochars had higher yields, carbon recovery rates, polarity and less aromaticity than biochars. Hydrothermal process reduced PPCPs’ load in sludge hydrochars effectively except caffeine and acetaminophen. The hydrochars prepared at intermediate and high temperatures (240 and 300 °C) had higher caffeine concentrations than the original sludge, which can be ascribed to the transformation of N-containing precursors. The highest CaCl2 extracted caffeine concentration occurred at intermediate temperature of 240 °C (48.1 μg/kg) due to the stronger affinity of caffeine in the high-temperature hydrochars. Caffeine was not detected in hydroxypropyl-β-cyclodextrin (HPCD) extract. Hydrochars prepared at low temperature (180 °C) had a higher acetaminophen concentration than the original sludge, which was attributed to the high thermal stability temperature of acetaminophen. Low- and intermediate-temperature hydrochars had higher CaCl2 extracted acetaminophen concentrations. The HPCD extracted acetaminophen was low with a range of nd to 6.72 μg/kg. In conclusion, PPCPs are less likely to constitute a limiting factor on the farm application of sludge hydrochar. This study provides theoretical support for the safe application of sludge hydrochar in the farmland.

High throughput extraction strategy for simultaneous analysis of 19 tetrabromobisphenol A and halogenated carbazole analogs in seafood

Tetrabromobisphenol A (TBBPA), halogenated carbazole (HCZ), and their analogs are the emerging pollutants invading the marine environment. So far, a few methods have been reported for the simultaneous analysis of these pollutants due to their large polarity difference. In this study, an effective extraction and cleanup strategy was developed for the simultaneous determination of 19 TBBPA and HCZ congeners in seafood. The 19 analytes could be directly analyzed through high performance liquid chromatography after ultrasonic extraction (methanol, duplicate ethyl acetate-acetone (1:1, v/v)) and gel permeation chromatography cleanup. The acceptable spike-recoveries were within 65.7–118.3%; the precision was intra-/inter-day RSDs: 0.0–6.7%/0.0–8.5%; and the matrix effects were between −14.1% and 12.4%. The detection limits and quantification limits were 0.002–0.014 and 0.020–0.200 µg g−1 dw, respectively. Additionally, this method successfully analyzed the seafood samples and the concentrations of these analytes were in range of nd–5.4 µg g−1 dw.

Early Cambrian oceanic island-arc magmatism at the paleo-Pacific margin of East Gondwana: Evidence from northern Victoria Land (Antarctica)

We present new geochemical, isotopic and geochronological data for two Cambrian magmatic sequences exposed in northern Victoria Land (Antarctica) at the eastern margin of the Ross-orogenic Wilson Terrane: (i) the metavolcanic and metaplutonic rocks from the Dessent tectono-metamorphic complex, and (ii) the boninite-derived mafic-ultramafic Niagara Icefalls igneous complex.The Dessent metaigneous rocks are subdivided into three main types. Type I metavolcanites show LREE-depleted chondrite-normalized patterns and high initial ɛNd (mostly +6 to +7). Metavolcanic and metaplutonic type II rocks show low MREE-HREE concentrations and initial ɛNd ranging from +2 to +4. Type III metavolcanites mostly differ from type II rocks in the somewhat elevated MREE-HREE abundances. Type I, II and III rocks geochemically resemble forearc basalts, boninites s.l. and firstarc volcanites, respectively, from the Izu-Bonin-Mariana island arc system. Zircon separated from two metaplutonic rocks documents a crystallization age of ~516 Ma.The Niagara Icefalls rocks display a wide range of Nd–Sr isotopic compositions (e.g., initial ɛNd + 5 to −8). Zircons separated from a gabbronorite and from a granitoid vein allowed us to date the building of the Niagara Icefalls igneous complex at ~537 Ma. The melts forming the Niagara Icefalls igneous complex were most likely sourced in a supra-subduction zone mantle wedge, which included both depleted mantle and slab-derived sedimentary components. We propose that the mafic-ultramafic Niagara Icefalls igneous complex and the metaigneous rocks of the Dessent tectono-metamorphic complex are fossil analogues of two distinct oceanic island arcs, which formed in the earliest and the late early Cambrian, respectively.

Structural, Electrical, and Optical Properties of 4H–SiC for Ultraviolet Photodetectors

The results of investigations of initial n-4H–SiC structures by various methods are presented. The structures represent a highly doped n+ substrate with epitaxial layers 5 μm thick grown by chemical vapor deposition (CVD). The concentration of uncompensated donors in the epitaxial layer is in the range of Nd – Na = (1–50) × 1014 cm–3. Using the results of X-ray diffraction analysis, it is found that, in order to obtain efficient 4H–SiC ultraviolet photodetectors, it is desirable to have structures of epitaxial layers in which the effect of point-defect gettering, leading to an increase in the lifetime of charge carriers and in the values of quantum efficiency, is observed. The photosensitivity of the investigated samples significantly depends on the degree of imperfection of the CVD epitaxial layer, which results in a change in the lifetime of charge carriers and, as a consequence, in a change in the quantum efficiency of 4H–SiC ultraviolet photodetectors.

Analysis of Alkylphenol ethoxylates (APEOs) from tannery sediments using LC–MS and their environmental risks

Alkyl phenol polyethoxylates (APEOs) are a major group of high production volume chemicals, extensively used as nonionic surfactants in industrial, agricultural and domestic sectors. These surfactants and its respective metabolites are found to be persistent and toxic. Mainly, they act as endocrine disruptors by mimicking the natural hormones. India being a developing country, witnesses pollution due to various industries including tannery. In the present study, sediment samples were collected from the Vellore district of Tamil Nadu, India to investigate the occurrence of APEOs. The sediments were extracted by ultrasonication and analyzed in a liquid chromatography mass spectrometer. Octyl phenol ethoxylates (OPEOs) were not observed in any of the samples. Nonyl phenol ethoxylates (NPEOs) were detected in the range of ND – 36 mg/kg with 85 % detection frequency. The occurrence of NPEOs in sediment indicates its wide usage in tannery and its partitioning behavior in environment. The levels of NPEOs in the study were found to be unsafe according to the sediment guidelines of various studies. Since NPEOs were observed in sediment samples, possibilities of occurrence of their monomers and metabolites cannot be ruled out. Therefore, further studies are warranted for understanding the levels of monomers and metabolites in order to ascertain the environmental risks more appropriately.

Occurrence and distribution of estrogenic chemicals in river waters of Malaysia

This study investigated the occurrence of eight endocrine-disrupting compounds (EDCs) in river water across five major regions in Malaysia, which are recognized as emerging micropollutants in the environment. The water samples were collected from surface water of Klang River, Pahang River, Kuantan River, Kelantan River and Terengganu River from Malaysia. The samples were extracted by liquid–liquid extraction using hexane and ethyl acetate and loaded on silica column for column chromatography. Gas chromatography–flame ionization detector was used to determine the concentration of the target compounds. The maximum concentration of E1, E2, E3, EE2, 1,2,4-triazole, MP, 3,4,4-trichlorocarbanilide and BPA detected is 26.5 ng/L, 15.5 ng/L, 3.6 μg/L, 68.8 ng/L, 6.5 ng/L, 5.75 ng/L, 392.5 ng/L and 37 μg/L, respectively. The high discharge of various emerging organic pollutants in the Klang River estuary ecosystem was caused by heavy industrial, plantation, residential and commercial activities from urbanized and populated cities. Overall, the occurrences show a higher concentration of EDCs when compared to developed countries. Other rivers such as Kuantan, Terengganu, Pahang and Kelantan are known as the major sources of water supply for domestic, industrial and agricultural purposes. Eight endocrine-disrupting chemicals were detected and estimated in five rivers of Malaysia. These target compounds are widely present in various rivers in the range of ND to 37 μg/L. The difference of occurrence of EDCs in these selected sampling sites reflects the distinct usage patterns of various chemicals, pesticide, cosmetic products, drugs all over Malaysia. The presence of BPA, E1 and E3 was observed to be a major contributor of endocrine disruptors.

Distribution and Human Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) and Polychlorinated Biphenyls (PCBs) in Marine Sediments and Seafood from Gunsan Coast of Korea

Distributions of 16 PAHs and 82 PCBs (including dioxin-like PCBs, DL-PCBs, and non-dioxin-like PCBs, NDL-PCBs) were investigated in sediment and seafood samples collected from the Gunsan coast, Korea. Total PAH (Σ16PAH) concentrations in sediments were in a range of 0.09~108 (mean: 57.9) ng/g-dry and gradually decreased outwardly. PAHs in marine sediments were originated from both combustion processes and petroleum sources. The total PCB (Σ82PCB) concentrations in sediments were in a range of nd (not detected)-0.64 (mean: 0.27) ng/g-dry, and DL-PCB (Σ12 dioxin-like PCB) were in a range of nd-0.293 (mean 0.054) pg-TEQ/g-dry. DL-PCB concentrations were correlated with NDL-PCB concentrations. In this study, the concentrations of PAHs and PCBs in marine sediments did not exceed the ecotoxicological values. Total PAH concentrations ranged from nd to 24.3 (mean: 5.35) ng/g-wet, benzo[a]pyrene (BaP) was not detected in seafood samples and the concentrations of Σ4PAH (BaP, chrysene, benzo[a]anthracene, and benzo[b]fluoranthene; nd-18.5 ng/g-wet) were lower than the maximum level (30 ng/g-wet) set by EU. The concentrations of NDL-PCBs in seafood samples were in a range of nd-0.19 (mean: 0.08) ng/g-wet less than 1% of the EU-set maximum level. The DL-PCB concentrations were below 0.1 pg-TEQ/g-wet, less than 1% of the EU-set maximum level. Human risk assessment of PAHs and PCBs via seafood consumption was carried out, and both lifetime cancer risk and non-cancer risk were low. Key Words: PAHs, Dioxin-like PCBs, Sediment, Seafood, Human risk assessment

Seasonal variation of antibiotics in surface water of Pudong New Area of Shanghai, China and the occurrence in typical wastewater sources

The occurrence of 26 antibiotics from three groups of Sulfonamides, Quinolones and Macrolides were investigated in the surface water of Pudong New Area, Shanghai in March (dry season) and June (wet season). As a result, the detection rates of the three groups were 20%, 81% and 56% (n = 10) with the concentration range of not detected–9.73 ng L−1, 30–344 ng L−1, and 14–107 ng L−1, respectively. Comparably, during wet season, the detection rates were 20%, 56% and 25% with the range of ND–14 ng L−1, 32–92 ng L−1, and ND–22 ng L−1, respectively. This indicates higher concentrations in dry season than that in wet season, which was attributed to the water dilution and weaker self-purification of the river during dry season. In addition, significant correlations were observed between SMA and most of Quinolones during dry season, and Quinolones and Macrolides during wet season, due to the similar sources. Considering for the typical wastewater sources in the investigated area, Quinolones were identified to be the most significant group in the aquiculture water. Furthermore, pharmaceutical manufacturing factory (PMF) and sewage treatment plant (STP) should be the serious point source pollution as the concentration in their effluents could range from ng L−1 to mg L−1. The occurrence and fate of antibiotics in the aquatic system of Pudong New Area need to be paid more attention to prevent the potential risk for human beings in the future study.

The Effect of pH and Concentration of KNO3 Solution to the Performance of Nd3+ Ion Selective Electrode Using HPMBP Ionophore

&lt;p&gt;The phenyl-3-methyl-4-benzoyl-5-pyrazolone (HPMBP) synthesized and characterized as ionophore in potentiometric analysis of ion selective electrode method (ISE) with polytetrafluoroethylene (PTFE) as the supporting phase. The pH and concentration of the ionic strength adjuster (ISA) were varied to know at the optimum pH and concentration of the ion-selective electrode (ESI) KNO&lt;sub&gt;3&lt;/sub&gt;, thus potential Nd&lt;sup&gt;3+&lt;/sup&gt; gives the best performance. Before use the PTFE membrane was immersed in a chloroform-HPMBP solution of 1.5-2.0% w/v for 24 h. The pH variation of the buffer solution was adjusted to the pH range of 2-10 using HCl and NaOH solutions, whereas the concentration of KNO&lt;sub&gt;3&lt;/sub&gt; varies from 10&lt;sup&gt;-1&lt;/sup&gt; to 10&lt;sup&gt;-3&lt;/sup&gt; M. The concentration range of Nd&lt;sup&gt;3+&lt;/sup&gt; is between 10&lt;sup&gt;-2&lt;/sup&gt; and 10&lt;sup&gt;-7&lt;/sup&gt; M. The electrode potential measurement results (E&lt;sub&gt;Nd&lt;/sub&gt;) obtained the best performance value at pH 4 with KNO&lt;sub&gt;3&lt;/sub&gt; concentration of 10&lt;sup&gt;-2&lt;/sup&gt; M, sensitivity (S) 18.39 ± 1.2 mV/decade and response time less than 23 s.&lt;/p&gt;

Radon 222 in drinking water resources of Iran: A systematic review, meta-analysis and probabilistic risk assessment (Monte Carlo simulation)

The current study was performed to review the conducted studies regarding the concentration of radon 222 in the tap drinking water; furthermore, by estimation of ingestion and inhalation effective dose, the health risk assessment in the adults and children using MCS technique was assessed. All related studies published among January 1990 to October 2016; were screened in the available databases such as Web of Science, PubMed, Science Direct, Scopus, SID, and Irandoc. The total effective dose was estimated by calculating Eing (Effective dose of ingestion) and Einh (Effective dose of inhalation) by Monte Carlo simulation (MCS) method. The range of ND ─ 40.9 Bq/L for radon 222 in water resources was proposed after evaluation of data collected from 13 studies with 1079 samples. The overall concentration of radon 222 in drinking water in Iran was 3.98: 95%CI (3.79 ─ 4.17 Bq/L). Also, the effective ingestion dose of radon 222 in adults age groups was 1.35 times higher than children. The rank order of drinking water resources based on the concentration of radon 222 was Spring > Spring and Well > Well > Spring and Qanat > Tap water. The overall concentration of radon 222 in drinking water in Iran was lower than WHO and EPA standard limits. Also, the rank order regarding area studied based on the concentration of radon 222 was Gillan > Mashhad > Mazandaran > Kerman > Yazd > Tehran > Kermanshah > Golestan > Hormozgan. The effective ingestion dose of radon 222 to consumers in the Gillan, Mashhad, Mazandaran, and Kerman were higher than WHO guidance (0.1 mSv/y). Also except consumers in the Hormozgan, inhalation effective dose radon 222, in the other investigated areas were higher than WHO guidance (0.1 mSv/y). Therefore, it is recommended to conduct the required programs regarding control and elimination of radon 222 concentration in Iranian drinking water supply.

Changes in conjugated linoleic acid and isoflavone contents from fermented soymilks using Lactobacillus plantarum P1201 and screening for their digestive enzyme inhibition and antioxidant properties

This research was the first to investigate the variations of conjugated linoleic acid (CLA), isoflavone, digestive enzyme inhibition, and antioxidant properties in hydrolysate soybean milks under fermentation using Lactobacillus plantarum P1201. The average CLA contents increased significantly in the range of ND → 0.91–1.75 mg/g during fermentation, whereas the isoflavone glucosides were markedly reduced (1570.01 → 548.41 µg/g, 65%) with the increase of aglycone contents (58.75 → 453.45 µg/g, 7.7 times). In particular, daidzein and cis-9, trans-11 CLA exhibited the predominant compositions (>50% and >90%) with considerable increases in fermented soybean milks. Total phenolic and flavonoid contents also slightly increased. Interestingly, fermented soybean extracts possessed potent α-glucosidase and pancreatic lipase inhibitory effects with average 32.4 → 55.5% and ND → 43.4% at a concentration of 500 μg/ml. Moreover, the antioxidant properties against three radicals increased markedly as the following order: ABTS (46.1 → 87.6%) > DPPH (38.8 → 77.4%) > hydroxyl (15.6 → 47.0%). Therefore, fermented hydrolysate milks might have attributed to enhance the soybean value.

The Panjal Traps

Abstract The Early Permian (290 Ma) Panjal Traps are the largest contiguous outcropping of volcanic (basaltic, andesitic and silicic) rocks within the Himalaya that are associated with the Late Palaeozoic break-up of Gondwana. The basaltic Panjal Traps have compositional characteristics that range from continental tholeiite to ocean-floor basalt but it is clear that crustal contamination has played a role in their genesis. The basalts that show limited evidence for contamination have Sr–Nd isotopes ( 87 Sr/ 86 Sr i = 0.7043–0.7073; ϵ Nd ( t ) = 0 ± 1) similar to a chondritic (subcontinental lithospheric mantle) source, whereas the remaining basaltic rocks have a wide range of Nd (ϵ Nd ( t ) = −6.1 to +4.3) and Sr ( 87 Sr/ 86 Sr i = 0.7051–0.7185) isotopic values. The primary melt composition of the low-Ti Panjal Traps is picritic with mantle potential temperatures ( T P = 1400°C to 1450°C) similar to ambient mantle. The silicic volcanic rocks were derived by partial melting of the crust, whereas the andesitic rocks were derived by mingling between crustal and mantle melts. The Panjal Traps initially erupted within a continental rift setting. The rift eventually transitioned into a nascent ocean basin that led to seafloor spreading and the formation of the Neotethys Ocean and the ribbon-like continent Cimmeria.

Multi-residue determination of organochlorine pesticides in vegetables in Kirklareli, Turkey by gas chromatography–mass spectrometry

The aim of this study was to investigate the level of organochlorine pesticides use for treatment of tomatoes, eggplants and cucumbers in Kirklareli, Turkey. Eighteen organochlorine pesticides were identified in vegetable samples using microwave or Soxhlet extraction, and results were obtained by gas chromatography–mass spectrometry. The optimized conditions were 1 mL/min for flow rate in the mobile phase, 1 μL for injection volume and 70 V for fragmentation potential. The analytical parameters show that the microwave oven extraction procedure provided the best results when compared to the Soxhlet extraction procedure. Samples were prepared for analysis with hexane‒dichlormethane (1: 1, v/v, 40 mL) using a solid-phase extraction method. The limits of detection and quantitation for the eighteen analytes were between 0.02–0.26 and 0.06–0.87 μg/L, respectively, and the relative standard deviations of the migration time ranged from 2.4 to 8.9%. The recoveries of surrogate spiked in vegetable samples ranged from 70 to 116%, respectively. The obtained concentrations of pesticides in all vegetables studied were proved in the range of ND–123 μg/kg. The organochlorine pesticide sum was below the legal limit, except for Endrin and Methoxychlor, which requires a further elucidation of the organochlorine pesticides pollution sources in the region. These studies on accumulation of organochlorine pesticides were necessary for accomplishing a comprehensive ecological risk assessment.

Organochlorine pesticide residues in dried cocoa beans obtained from cocoa stores at Ondo and Ile-Ife, Southwestern Nigeria.

Levels of organochlorine pesticides (OCPs) were determined in dried cocoa beans obtained from cocoa produce stores at Ondo and Ile-Ife, Southwestern Nigeria. Cocoa beans samples were sun dried to a constant weight, pulverized and soxhlet extracted with dichloromethane to obtain the OCPs. Qualitative identification and quantitative evaluation of the extracted OCPs after clean-up on silica gel were accomplished with the aid of a Gas Chromatography coupled with an Electron Capture Detector (GC-ECD). Levels of OCPs in cocoa beans from Ondo had a mean range of ND (p, p'-DDE) to 82.17±54.53ng/g (p, p'-DDT) were higher than the OCPs levels in cocoa beans from Ile-Ife with a mean range of 0.37±0.63ng/g (Endrin) to 57.76±81.48ng/g (p, p'-DDT). The higher levels of OCPs detected in the cocoa beans from Ondo could be an indication of higher volume of OCPs application by cocoa farmers in Ondo and its environs since cocoa plantations were more concentrated than Ile-Ife environs. Levels of OCPs determined in the cocoa beans were within the Maximum Residue Limit (MRLs) for OCPs set by the World Health Organization/Food and Agricultural Organization. The study established the presence of OCPs in an important crop of Nigeria. Hence, there is the need to keep monitoring ecotoxicological chemical substances in agricultural food products of Nigeria so as to take steps that ensure health safety of end users.

Seasonal influences on the levels of particulate Cd, Cr and Pb in Kuantan River, Pahang

Introduction: Temporal and spatial variations of selected toxic element distributions were studied in the Kuantan River waters. Methods: Water samples from 9 sampling stations were taken from downstream of the estuary towards the upstream of the Kuantan River during the rainy and dry season. Particulate Cd, Cr and Pb were filtered, dried, weighed and analyzed using Teflon Bomb digestion processes. Results: The concentration of particulate Cd, Cr and Pb were in the range of ND to 14.480 mg L-1 , 6.047 to 271.497 mg L1 and 0.646 to 174.859 mg L-1 , respectively. The distribution of the elements in suspended particulate matter was found influenced by the rainy season and dry season. Particulate metals obtained mostly higher in May 2012 (dry season) while Cd and Cr were found above the limits authorize by the International Commission for the Protection of the Rhine against Pollution (ICPR). Conclusions: Correlation matrix between various parameters revealed that most of the parameters were found to bear a statistically significant correlation with each other.