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1.
In this study we present quantitative elemental analysis techniques like energy dispersive X-ray fluorescence analysis and instrumental neutron activation analysis to assess the impact of industrial discharge on environment. Two cases are discussed, i.e., (a) enrichment of zinc levels in the soil (1080 ± 76 mg kg?1) and zinc uptake ranging between 628 and 40 mg kg?1 in edible plants and cereals grown in agricultural fields near an active zinc smelter, Rajasthan; (b) depth-wise distribution of Cr, Pb and other metals in the sediment core samples from Sundarban wetland, West Bengal, indicating waste discharge from tanneries and other industries.  相似文献   

2.
A high-performance liquid chromatography with ultraviolet (HPLC-UV) detection method after derivatisation was developed for the first time for the novel fungicide zinc thiazole residue in tobacco samples. Field trials in two different locations were conducted to investigate the dissipation and residue of zinc thiazole in tobacco leaves and soil. The average recoveries of zinc thiazole were in the range of 82.5%–93.9% with relative standard deviations (RSDs) of 1.2%–9.1%. The zinc thiazole showed a rapid dissipation rate in fresh tobacco leaves with the half-lives of 1.1–1.6 days. The terminal residues of zinc thiazole in cured tobacco leaves and soil were 2.8–28.0 mg kg?1and <0.05 mg kg?1, respectively. The results could be used to establish the maximum residue limits (MRLs) and provide guidance for the scientific use of zinc thiazole in agriculture.  相似文献   

3.
Two independent field trials were performed in Guizhou and Hunan, China in 2013 to investigate the dissipation and residue levels of saisentong in tobacco and soil. A novel and accurate method using high-performance liquid chromatography with diode array detection was developed and validated to determine saisentong levels in tobacco and soil. The average recovery of saisentong at fortification levels of 0.5, 2.5, 5.0 and 50.0 mg kg?1 in fresh tobacco ranged from 75.92 to 107.40% with a relative standard deviation (RSD) of 0.94 to 7.55%, that at fortification levels of 0.5, 2.0 and 5.0 mg kg?1 in tobacco powder ranged from 74.96 to 94.43% with a relative standard deviation (RSD) of 4.38 to 8.14%, and that at fortification levels of 0.1, 0.5 and 5.0 mg kg?1 in soil ranged from 86.90 to 100.0% with an RSD of 1.38 to 4.62%. The limit of detection (LOD) of saisentong was 0.15 mg?kg?1 in tobacco and 0.03 mg kg?1 in soil, and the limit of quantification (LOQ) was 0.5 mg kg?1 in tobacco and 0.1 mg kg?1 in soil, respectively. For field experiments, the half-lives of saisentong in tobacco from Guizhou and Hunan were 5.9 and 1.6 days, respectively; those in soil were 14.7 and 12.0 days, respectively. The results suggest that the saisentong dissipation curves followed the first-order kinetic. The terminal residues of saisengtong in tobacco ranged from 0.5 to 9.39 mg kg?1 at pre-harvest intervals (PHI) of 7, 14 and 21 days.  相似文献   

4.
A study of the biodegradation of imidacloprid in soil was carried out under laboratory conditions. Sandy soil samples were fortified with imidacloprid at 50, 100 and 150 mg kg?1 along with 45 x 107 colony forming units (cfus) of Bacillus aerophilus and the samples were compared with unamended soil. The samples were extracted with acetonitrile, cleaned up by treatment with primary secondary amine sorbent and graphitised carbon black. The residues of imidacloprid and its metabolites were analysed by high performance liquid chromatography. The parent compound, imidacloprid, was found to be more persistent in both the treatments. Among metabolites, the highest values were obtained for urea and olefin while 5-hydroxy, 6-chloronicotinic acid (6-CNA), nitrosimine and nitroguanidine (NTG) were also observed in all the treatments in amended soil. In case of unamended (control) soil, 6-CNA was found to be the most persistent metabolite followed by olefin, urea, 5-hydroxy, nitrosimine and NTG metabolites. Total imidacloprid residues for control soil samples followed first-order kinetics at 50 and 150 mg kg?1 but in case of control imidacloprid fortified at 100 mg kg?1, the total residues of imidacloprid and its metabolites followed pseudo-first-order kinetics. The respective half-life value for 50 mg kg?1 was 25.08 days and 30.10 days for both 100 and 150 mg kg?1. However, total imidacloprid residues followed pseudo-first-order kinetics for its applications at 50, 100 and 150 mg kg?1 in sandy loam soil amended with B. aerophilus. The half-life values for 50, 100 and 150 mg kg?1 were worked out to be 14.33, 15.05 and 18.81 days, respectively. With the use of B. aerophilus, the reduction percentage of initial applied dose imidacloprid in sandy loam soil was found to be higher in all the three doses as compared to that of the control samples.  相似文献   

5.
Study on the residue dynamics of chlorpyrifos and cypermethrin in/on pomegranate (Punica granatum L.) and soil was carried out by conducting supervised field trials as per good agricultural practices. A modified QuEChERS was used to extract the insecticides in pomegranate peel and aril and soil. The limit of quantification (LOQ) of chlorpyrifos and cypermethrin were 0.01 and 0.05 mg kg?1, respectively. Residues of the insecticides remained on the fruit surface and movement to the edible part (aril) was not observed. The residues after treatment on fruit peel were 2.46 and 3.51 mg kg?1 and 2.84 and 4.54 mg kg?1 for chlorpyrifos and cypermethrin, respectively, from recommended and double dose treatments. Chlorpyrifos residues degraded faster compared to cypermethrin. The pre-harvest intervals (PHIs) of chlorpyrifos were 22 and 35 days and those of cypermethrin 50 and 73 days, respectively, at recommended and double dose treatments. In the experimental field soil after the second application chlorpyrifos residues were 0.21 and 0.46 mg kg?1 and cypermethrin residues 0.15 and 0.36 mg kg?1. At harvest, both pesticides showed residues below the LOQ. Based on this study, application of cypermethrin towards harvest may be avoided whereas chlorpyrifos can be applied with 22 days PHI.  相似文献   

6.
Arsenic (As) in soil is a contaminant originated from human activities including pesticide use, mining and ore processing operations. In this work, As concentration in soil samples collected around the monazite processing facility, Pathum Thani, Thailand, was investigated. The collections of 24 soil samples were collected from the monazite processing area and 7 soil samples were collected from the control area without the processing activity of the same facility. Soils were digested with the mixture of HNO3, HClO4 and HF using a microwave digester. Inductively coupled plasma mass spectrometer (ICP-MS) equipped with an octopole reaction system (ORS) was used to determine the concentration of As in soils after the acid digestion. JB-3 (igneous rock) was the standard reference material used to check the accuracy of the method. It was found that the analytical results showed good agreement with the certified values. As concentration in soils collected from the monazite processing area ranged from 3.85 to 36.01 mg kg?1 with the mean of 13.06 mg kg?1. The concentration of As higher than the US EPA cancer soil screening level (22 mg kg?1) was observed for only one sample. The control area showed As concentration varied from 9.59 to 14.19 mg kg?1 with the mean of 11.97 mg kg?1. The obtained results from this work were compared with the contaminated soil data of Amphoe Ron Phibun, Nakhon Si Thammarat, Thailand.  相似文献   

7.
Trifloxystrobin and tebuconazole are used for control of Sigatoka leaf spot disease of banana. This study was conducted to evaluate residue persistence of the fungicides in/on banana fruit, other edible parts and soil after spray application of the combination formulation, Nativo 75 WG, at the standard dose, 87.5 + 175 and double dose, 175 + 350 g a.i. ha?1. The fungicides were extracted from banana and soil with acetone, partitioned into dichloromethane and cleaned-up using activated charcoal for trifloxystrobin and primary/secondary amine (PSA) for tebuconazole samples. The limit of quantification of the method was 0.05 mg kg?1 for both fungicides. Initial residues of trifloxystrobin were 0.444 and 0.552 mg kg?1 in/on banana with peel (whole fruit), which reached <0.05 and 0.065 mg kg?1 after 30 days from treatment at the standard and double doses, respectively. Tebuconazole residues were 0.636 and 960 mg kg?1 initially and reduced to 0.066 and 0.101 mg kg?1 after 30 days. Trifloxystrobin and tebuconazole degraded with the half-life of about 11 days. Trifloxystrobin or its metabolite was not detected in the fruit pulp. Tebuconazole being systemic in nature moved to the fruit pulp which was highest on the 3rd day (0.103 and 0.147 mg kg?1) and remained for 15 days. Matured banana fruit, flower, pseudostem and field soil were free from fungicide residues. For consumption of raw banana 43 days pre-harvest interval (PHI) is required after treatment of the combination formulation. Therefore application of the fungicides towards maturity stage of the fruits may be avoided.  相似文献   

8.
The phyto-accumulation efficacy of selenium (Se) from soil by chickpea plant is reported. Chickpea plants were grown in soil having different concentrations (1–4 mg kg?1) of Se. Samples of soil and different parts of chickpea plants in Se rich soil were analyzed for determination of Se concentrations by instrumental neutron activation analysis (INAA). Samples were irradiated in self-serve facility of CIRUS reactor, BARC, Mumbai at a neutron flux of the order of 1013 cm?2 s?1. The gamma activity at 264.7 keV of 75Se (119.8 d) was measured using a 45% relative efficiency HPGe detector coupled to MCA. Dependence of Se distribution in soil and plants on its spiking concentration was evaluated in this work. The Se concentrations determined in plant parts grown in control soil and in soil spiked with Se (4 mg kg?1) are in the range of 0.6–0.8 and 65–68 mg kg?1 respectively.  相似文献   

9.
Flumorph is an Oomycete fungicide, which is used extensively as an effective fungicide in vegetables and fruits, but little is known about its effect on nontarget soil organisms. In the present study, biochemical responses including changes in the activity of antioxidative enzymes catalase (CAT), superoxide dismutase (SOD), glutathione-S-transferase (GST), malondialdehyde (MDA), and DNA damage induced by flumorph were investigated in earthworms (Eisenis fetida). The CAT concentrations were stimulated at 5.0 mg kg?1 over 28 days and inhibited at 10 and 20 mg kg?1, except 10 mg kg?1 on days 21 and 28 compared with the controls. The overall SOD activities were inhibited except 5 mg kg?1 on day 28 and 10 mg kg?1 on days 7 and 14. Meanwhile, the GST activities were stimulated on day 7 and decreased on the other days in summary. The MDA activities were increased notably at 5, 10, and 20 mg kg?1 after 14 days. Clear dose-dependent DNA damage to Eisenia fetida was observed by olive tail moments in comet assay compared with controls. The results demonstrate that flumorph induces oxidative stress and DNA damage to earthworms, and the effects may be the important mechanisms of its toxicity.  相似文献   

10.
A field experiment was conducted to evaluate clofentezine residue levels and dissipation trend in tangerine and soil for the safe application of clofentezine. A modified QuEChERS-HPLC-UVD method was developed to analyse clofentezine in tangerine and soil. Tangerine samples were homogenised and extracted by acetonitrile and then cleaned up with dispersive solid phase extraction (dSPE) by primary and secondary amine (PSA) and C18. Clofentezine residue was determined by high-performance liquid chromatography (HPLC) with a UV detector (UVD) at the wavelength of 268 nm. The presented method achieved the good linear relationship within the range from 0.05 to 5.0 mg kg?1 for clofentezine (R2 > 0.998). At the fortification levels of 0.05, 0.50 and 1.00 mg kg?1 in tangerine pulp, tangerine peel and soil, recoveries ranged from 75.9% to 117.7% with relative standard deviations (RSD) less than 8.2%. In the supervised field trials, the half-lives of clofentezine in tangerine and soil were approximately 11.3 and 8.6 days, respectively. At pre-harvest interval of 21 days, the residue of clofentezine in tangerine was below the maximum residue limits (MRL) (0.5 mg kg?1). Clofentezine (Water Dispersible Granule, 80%) was recommended to be sprayed twice and the recommended dosage ranged from 250 to 375 mg kg?1.  相似文献   

11.
Persistence and dissipation of fluopicolide and propamocarb were studied on cabbage and soil as per good agricultural practices over a period of 2 years. A modified QuEChERS analytical method in conjunction with gas chromatography (GC) and GC–mass spectrometry was used for analysis of fluopicolide and its metabolite, 2,6-dichlorobenzamide, and propamocarb in cabbage and soil. The results of the method validation were satisfactory with recoveries within 74.5–100.81% and relative standard deviations 4.8–13.9% (n = 6). The limit of detection (LOD) and limit of quantification (LOQ) of both fluopicolide and 2,6-dichlorobenzamide were 0.003 µg mL?1 and 0.01 mg kg?1, respectively. The LOD and LOQ of propamocarb were 0.03 µg mL?1 and 0.1 mg kg?1, respectively. During 2013, the initial residue deposits of fluopicolide on cabbage were 0.60 and 1.48 mg kg?1 from treatments at the standard and double doses of 100 and 200 g a.i. ha?1 which dissipated with the half-life of 3.4 and 3.7 days. During 2014, the residues were 0.49 and 1.13 mg kg?1 which dissipated with the half-life of 4.2 and 5.1 days. Propamocarb residues on cabbage were 5.36 and 12.58 mg kg?1 in the first study (2013) and 4.85 and 10.26 mg kg?1 in the second study (2014) from treatments at the standard and double doses of 1000 and 2000 g a.i. ha?1, respectively. The residues dissipated with the half-life of 4–5.5 days. The preharvest interval, the time required for fluopicolide + propamocarb residues to dissipate below the maximum residue limits (notified by EU) at the standard dose, was 11.8 and 14 days during 2013 and 2014. Residue of 2,6-dichlorobenzamide was always <LOQ in cabbage. Residues of fluopicolide, 2,6-dichlorobenzamide and propamocarb were <LOQ in field soil at harvest.  相似文献   

12.
A modified QuEChERs method with liquid chromatography-tandem mass spectrometry for analysis of guadipyr residue and dissipation in rice matrices, paddy soil and paddy water was developed and validated. Mean recoveries and relative standard deviations in paddy soil, paddy water, rice plant, rice straw, rice hull and husked rice matrices at three spiking levels were 83.1–116.5% and 1.6–9.5%, respectively. The half-life of guadipyr was determined in 2 years at three different field sites in China via a dissipation experiment. The half-lives of guadipyr in paddy water were 0.22–0.37 days, 0.24–3.33 days in paddy soil and 0.44–1.90 days in rice plant. The terminal residues of guadipyr ranged from ND (concentrations of guadipyr were below limit of detection) to 50 μg kg?1 in paddy soil, 10–470 μg kg?1 in rice hull, ND70 μg kg?1 in husked rice and ND to 110 μg kg?1 in rice straw. The results would be helpful in fixing maximum residue limit of guadipyr, a new insecticide, in rice.  相似文献   

13.
Residue dissipation of hexaconazole and isoprothiolane in the rice field ecosystem was determined by gas chromatography coupled with electron capture detector. Hexaconazole and isoprothiolane (33% microemulsion) were applied at two dosages, 396 g a.i. ha–1 (the recommended dosage) and 594 g a.i. ha–1 (1.5 times the recommended dosage) in the experimental fields in Guizhou, Hunan and Heilongjiang provinces, China, during 2011–2012. The limits of detection and limits of quantification in brown rice were 0.006 and 0.02 mg kg–1 for hexaconazole, 0.0072 and 0.024 mg kg–1 for isoprothiolane, respectively, and they were much below the maximum residue limits (MRLs, 0.1 mg kg–1 for hexaconazole and 1.0 mg kg–1 for isoprothiolane) set by China. Average recoveries of hexaconazole in water, soil, rice plants and brown rice ranged from 77.3% to 93.8% and for isoprothiolane ranged from 78.1% to 99.9% with relative standard deviations < 10%. The results showed that during harvest, the terminal residue levels of hexaconazole and isoprothiolane in brown rice samples were well below the MRLs of China following the interval of 7 days after last application. Therefore, a dosage of 396 g a.i. ha–1 was recommended, which could be considered as safe to human beings.  相似文献   

14.
A modified quick, easy, cheap, effective, rugged and safe (QuEChERS) method for the analysis of triallate residue in wheat and soil was developed and validated. Multi-walled carbon nanotubes were used as clean-up sorbent. The residual levels and dissipation rates of triallate in wheat and soil were determined by liquid chromatography–tandem mass spectrometry. The limit of quantification was established as 0.01, 0.02 and 0.05 mg kg?1 for soil, wheat and wheat plant samples, respectively. The average recoveries of triallate ranged from 77% to 108% at fortified levels of 0.01–0.5 mg kg?1 with relative standard deviations of 3.0–8.4% (n = 5). From residue trials at three geographical experimental plots in China, the results showed that the half-lives of triallate in soils were 1.13–1.63 days. For trials applied according to the label recommendation, the final residues of triallate in wheat at harvest time were all below 0.05 mg kg?1 (the maximum residue levels of China, Japan, Korea and the US).  相似文献   

15.
The total metal concentration and bioaccessible concentration of Cr, Mn, Fe, Cu, Zn, Se in Momordica charantia, Asparagus racemosus, Terminalia arjuna and Syzyzium cumini were measured by instrumental neutron activation analysis and by inductively coupled plasma mass spectrometry analysis (ICP-MS). The bioaccessible concentrations were determined in the gastrointestinal digest obtained after treating dried powdered samples sequentially in gastric and intestinal fluid of porcine origin at physiological conditions. The bioaccessible concentration of Fe was in the range of 58–67 mg kg?1, Mn was 10.2–14.6 mg kg?1, Cu was 3.7–4.8 mg kg?1 and Zn was 10.6–18.4 mg kg?1, were within the safety limits set for vegetable food stuff set by Joint FAO/WHO. The bioaccessibility of Zn, an essential element, was high (40–50 %) in M. charantia and in S. cumini. In addition, the total metal contents and bioaccessible concentration of Ni, Se, Cd and Pb in these samples were measured by ICP-MS. The total Cd content in S. cumini (2.6 ± 0.2 mg kg?1) and its bioaccessible concentration (0.6 mg kg?1) were strikingly high as compared to the other samples. Though total Hg contents were determined by ICP-MS, but their bioaccessible concentrations were below the detection limit (0.036 mg kg?1).  相似文献   

16.
《Analytical letters》2012,45(2):394-405
In order to study the regional distribution, characterization, and possible source of Cadmium in the eastern Tibetan Plateau, samples of leaves, xylem, twigs, bark, and roots of timberline forest trees (fir or spruce) and soils at depths from 0 to 40 cm were collected in eight sites in Hengduan Mountains. According to Cd contents, organs and tissues were divided into three groups: the highest-level organ (roots: 0.237 mg · kg?1), the high-level organ/tissue (bark: 0.183 mg · kg?1 and twigs: 0.159 mg · kg?1), and the low-level organ/tissue (xylem: 0.054 mg · kg?1and leaves: 0.048 mg · kg?1). Cd contents in Transect A were a little higher than Transect B. Sites near pollutant sources and high-levels are more sensitive to Cd pollution and accumulated more Cd, while Cd contents in sites far away from pollutant sources and low-level organ/tissue were relatively low. It is suggested that the eastern Tibetan Plateau has already been polluted by the influence of general circulation to some extent. Nevertheless, low Cd contents in some sites prove that high mountains may barricade Cd pollutants from monsoon.  相似文献   

17.
The CCQM-P106 pilot study was organized by the inorganic working group of the Comité Consultatif pour la Quantité de Matière (CCQM) as a feasibility comparison to study the applicability of different analysis methods to the polypropylene sample and test the abilities of the participants for measuring the Cd, Cr, Hg and Pb in polypropylene. National Institute of Metrology P.R. China (NIM) acted as the coordinating laboratory of this pilot study. There were 21 laboratories that submitted the final results. The median values of the mass fraction of Cd, Cr, Hg and Pb were 36.12 mg kg?1 (the median absolute deviation about the median (MADe) = 0.46 mg kg?1), 252.5 mg kg?1 (MADe = 3.4 mg kg?1), 387.0 mg kg?1 (MADe = 10.1 mg kg?1) and 466.2 mg kg?1 (MADe = 8.9 mg kg?1), respectively. Isotope dilution mass spectrometry (IDMS), inductively coupled plasma-mass spectrometry (ICP-MS), inductively coupled plasma-optical emission spectrometry (ICP-OES), atomic absorption spectrometry (AAS), instrumental neutron activation analysis (INAA) and X-ray fluorescence (XRF) measurement methods were used, and microwave digestion was used by the most of the participants. In general, very good agreement of the results was observed. Moreover, compared to the results of other methods, the results of IDMS still showed less spread amongst laboratories and had a smaller uncertainty. In addition, the results of some analytes used by XRF and INAA also got satisfactory agreement with the median value.  相似文献   

18.
This study evaluates the antidepressant-like effect and analysed the qualitative and quantitative 74 phenolic standards of ethyl acetate fraction from Tabernaemontana catharinensis leaves. Acute administration of fraction in mice reduced the immobility time in forced swimming and tail suspension tests confirming its antidepressant-like activity. The anti-immobility effect elicited by this fraction was prevented by the pretreatment of mice with PCPA (100 mg kg?1), ketanserin (5 mg kg?1), SCH 23,390 (0.05 mg kg?1) or yohimbine (1 mg kg?1). A sub effective dose of the fraction produced a synergistic effect with fluoxetine (5 mg kg?1). Chromatographic analysis identified 4-hydroxybenzoic and p-coumaric acids in the ethyl acetate fraction from T. catharinensis. Capillary electrophoresis presented 7.34 ± 0.02 mg g?1 of p-coumaric acid concentration in the fraction. Therefore, it is possible that antidepressant-like effect elicited by ethyl acetate fraction from T. catharinensis be dependent on the p-coumaric acid.  相似文献   

19.
《Analytical letters》2012,45(11):1952-1964
The distributions of cadmium and lead in marine sediments, surrounding soil, stones, and atmospheric particulate matter were determined at different locations in Split, Croatia. The determination of cadmium and lead was performed by flame atomic absorption spectrometry whereas atmospheric particulate matter samples were analyzed by inductively coupled plasma–optical emission spectrometry. Cadmium concentrations in the stones and soil were between 0.2 to 0.6 µg g?1 and 0.2 to 0.9 µg g?1. The concentration in the atmospheric particulate matter were <0.2 µg m?2 d?1(detection limit) to 1.4 µg m?2 d?1. Lead concentrations in marine sediments, stones, soil, and atmospheric particulate matter ranged from 31.2 to 144.4 µg g?1, 9.3 to 29.4 µg g?1, 11.3 to 66.1 µg g?1, and 0.5 to 241.4 µg m?2 d?1, respectively. The relationship between determined parameters was established using principal component analysis and the results are in agreement with the assumption that anthropogenic sources play important roles for lead and cadmium distribution.  相似文献   

20.
Hongzhe Tian 《Chromatographia》2011,73(5-6):457-462
A method for determination of chlormequat (CCC) residue in fruits by liquid chromatography?Ctandem mass spectrometry (LC?CMS?CMS) was developed. Residue of CCC was extracted from samples with methanol?Cwater (v/v, 1:1) containing 1.0% acetic acid, cleaned up by strong cationic exchange (SCX) cartridge, and then determined by LC?CMS?CMS. The method showed good linearity over the concentration range 0.002?C5.0 mg kg?1 with correlation coefficient above 0.997. The limit of detection (LOD) and limit of quantitation (LOQ) for CCC were 5 × 10?4 mg kg?1 (S/N = 3) and 0.002 mg kg?1 (S/N = 10), respectively. Recoveries for CCC at three spiked levels (0.025, 0.050, and 0.20 mg kg?1) were in the range 80?C102%. Estimation of measurement uncertainty was calculated for CCC at the level of 0.025 mg kg?1 in fruits. The results demonstrated that the uncertainty of recovery was the main contribution to the combined standard uncertainty. The relative combined standard uncertainties associated with the method ranged from 11 to 13%, depending on the sample matrices.  相似文献   

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