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1.
Ground-based ambient air monitoring was conducted at five different locations in and around Patiala city (29°49′–30°47′N Latitude, 75°58′–76°54′E Longitude) in Northern India in order to determine the impact of open burning of rice (Oriza sativa) crop residues on concentration levels of suspended particulate matter (SPM), sulphur dioxide (SO2) and nitrogen dioxide (NO2). Covering sensitive, residential, agricultural, commercial and urban areas, sampling of these pollutants was organised during August 2006 to January 2007 and August 2007 to January 2008 casing two rice crop residue burning periods (October–November) using a high volume sampling technique combined with gaseous sampling systems. Gravimetric analysis was used in the estimation of total suspended particulate matter (TSPM) whereas SO2 and NO2 concentration was determined using spectrophotometer (Specord205, Analytikjena). Monthly average concentrations of SPM, SO2 and NO2 have shown significant up and down features at all the selected sampling sites during the study period. Monthly average concentrations (24 hour) of SPM, SO2 and NO2 varied from 100 ± 11 µg m?3 to 547 ± 152 µg m?3, 5 ± 4 µg m?3 to 55 ± 34 µg m?3 and 9 ± 5 µg m?3 to 91 ± 39 µg m?3. Substantially higher concentrations were recorded at the commercial area site as compared to the other sampling sites for all the targeted air pollutants. Levels of SPM, SO2 and NO2 showed clear increase during the burning months (October–November) incorporated with the effect of meteorological parameters especially wind direction, precipitation and atmospheric temperature.  相似文献   

2.
Jing Wang  Wen Meng  Zhenjie Ni  Sijia Xue 《中国化学》2011,29(10):2109-2113
A series of novel N‐(substituted benzyl)‐3,5‐bis(benzylidene)‐4‐piperidones 5a – 5o were synthesized with substituted benzylamines as raw materials via a series of Michael addition, Dieckmann condensation, hydrolysis decarboxylation and aldol condensation. The structures were confirmed by 1H NMR, IR, MS techniques and elemental analysis. Assay‐based antiproliferative activity study using leukemic cell lines K562 revealed that most of the title compounds have high effectiveness in inhibiting leukemia K562 cells proliferation, among which the compounds 5g (IC50=7.81 µg·mL−1), 5k (IC50=6.35 µg·mL−1), 5l (IC50=7.20 µg·mL−1), and 5o (IC50=5.79 µg·mL−1) have better inhibition activities than standard 5‐fluorouracil (IC50=8.56 µg·mL−1).  相似文献   

3.
《Analytical letters》2012,45(11):1921-1930
This paper describes a simple and sensitive method for the determination of manganese in human urine by graphite furnace atomic absorption spectroscopy (GFAAS), which includes sample preparation by microwave digestion. Matrix modifier combinations, the digestion power, pyrolysis, and atomization temperatures were optimized. A mixture of 5.0 µg Pd(NO3)2 and 3.2 µg Mg(NO3)2 modifier presented the best performance. The optimal temperatures for pyrolysis and atomization were 1500°C and 1950°C, respectively. The GFAAS method was compared to inductively coupled plasma–mass spectrometry (ICP–MS) for the determination of manganese in urine. Analytical figures of merit for GFAAS and ICP–MS were: accuracy (3.46%, 2.19%), precision (3.61%, 5.84%), LOD (0.109 µg · L?1, 0.015 µg · L?1), LOQ (0.327 µg · L?1, 0.045 µg · L?1), and recovery (80–100%, 74–89%). Both methods were employed for the determination of Mn in urine and the results were compared statistically.  相似文献   

4.
《Comptes Rendus Chimie》2015,18(10):1183-1191
The level of contamination by mercury associated with airborne particulate matter in Krakow was determined. Samples of PM10 were collected on quartz filters using low-volume samplers. The total particulate mercury (TPM) concentrations in collected samples were determined by mercury analyser MA-3000 (Nippon Instruments Corporation). The reported results include also data on the carbonaceous aerosol and inorganic ions concentrations during the reported sampling campaign. The average concentration of the Total Particulate Mercury (TPM) in Krakow (Poland) was 0.22 ng·m−3 (during the period from 22 February to 2 March) and 0.49 ng·m−3 (on 3 March). A marked correlation between TPM and elemental carbon (EC) as well as with Cl was found. No significant association of the TPM with NO3 and SO42– could be shown. The dry deposition flux of mercury was calculated as an average over the sampling period and was 47.3 ng·m−2·d−1.  相似文献   

5.
《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   

6.
A facile,rapid and sensitive spectrophotometric method was developed for the determination of carbaryl in itsformulations,water and grain(rice and wheat)samples with newly synthesised reagent.The proposed method wasbased on the alkaline hydrolysis of carbaryl pesticide and thus resulted 1-naphthol was coupled with diazotised4,4'-methylene-bis-m-nitroaniline in basic medium(pH 9)to give red colored product having λ_(max)480 nm for dia-zonium method(DM)or 1-naphthol reacts with 4,4'-methylene-bis-m-nitroaniline in the presence of oxidising agentpotassium dichromate(K_2Cr_2O_7)to give red colored product having λ_(max)510 nm for oxidation method(OM).Theformation of colored derivatives with the coupling agent is instantaneous and stable for 48 h(DM)and 32 h(OM)respectively.Beer's law was obeyed in the concentration range of 0.2—10.0 μg·mL~(-1)for DM and 0.2—0,150μg·mL~(-1)for OM.The proposed methods are sensitive,easy to operate and permitted for the determination of car-baryl with detection limits of 0.028 μg·mL~(-1)for DM and 0.024 μg·mL~(-1)for OM respectively.The experimentalresults indicate that the procedure can eliminate the fundamental interferences caused by other pesticides andnon-target ions,which made the methods more sensitive and selective.The method was applicable to the determina-tion of carbaryl residue in water and food grain samples up to μg level.  相似文献   

7.
Summary: The objective of this research was to verify the influence of adding increasing amounts of lauric acid on the functional properties of homogenized films made from gelatin, triacetin and a blend of palmitic and stearic acids. The films were characterised with respect to their visual aspect, water vapour permeability (WVP), water solubility, mechanical properties (tensile strength and percent elongation), oxygen permeability (O2P), opacity (OP) and melting and glass transitions temperatures. The films produced were malleable and macroscopically homogeneous. The addition of 1% of lauric acid to the film of gelatin, triacetin and blend of palmitic and stearic acids (5.84 ± 0.31 gmm · m−2 dkPa) caused a slight decrease in WVP. The additions of 2.5% (5.70 ± 0.76 gmm · m−2 dkPa), 5% (5.38 ± 0.64 gmm · m−2 dkPa) and 10% (4.50 ± 0.55 gmm · m−2 dkPa) of lauric acid were sufficient to make a significant difference in the WVP at the higher levels used. As compared to the gelatin and triacetin film, the addition of lauric acid at all the concentrations studied resulted in a slight increase in the film solubility. The addition of hydrophobic substances to gelatin/triacetin films (15.26 ± 0.28 cm3 · µm · m−2 dkPa) favoured an increase in O2P permeability, this effect being greater in the films made from gelatin, triacetin, blend of palmitic and stearic acids and 10% lauric acid (24.48 ± 0.07 cm3 · µm · m−2 dkPa). The increasing addition of lauric acid significantly reduced the tensile strength and increased elongation of the films composed of gelatin, triacetin and blend that being more evident at the concentrations of 5% (67.58 ± 1.23 MPa and 11.45 ± 0.57%) and 10% (63.50 ± 1.56 MPa and 12.90 ± 0.57%). The addition of 1% (OP, 27%) and 10% (OP, 28%) of lauric acid induced no visible effect on the opacity of the films. The thermogrammes showed three transitions for the gelatin/triacetin/stearic-palmitic blend/1% lauric acid films (−57.42 °C, 23.74 °C and 44.11 °C) and two for the gelatin/triacetin/stearic-palmitic acids blend/10% lauric acid films (−56.22 °C and 17.35 °C). As observed by DSC, the addition of fatty acids resulted in the appearance of more than one melting peak for all films in relation to the gelatin and triacetin film.  相似文献   

8.
On the basis of the principle of combination of active groups, a series of novel N‐(4‐([2,2′:5′,2′′‐terthiophen]‐5‐yl)‐2‐methylbut‐3‐yn‐2‐yl) benzamide derivatives were designed, synthesized and systematically evaluated for their antiviral activity against tobacco mosaic virus (TMV). The bioassay results showed that most of these compounds displayed good anti‐TMV activity, and some of them exhibited higher antiviral activity than commercial Ningnanmycin. Especially, compound 8e with excellent anti‐TMV activity (inactivation activity, 92.3%/500 µg·mL?1; curative activity, 85.7%/500 µg·mL?1 and protection activity, 64.7%/500 µg·mL?1) emerged as a potential inhibitor of plant virus TMV. Quantitative structure‐activity relationship studies proved that the van der Waals volume (V) and electronic parameter (∑(∑σo+σp) and ∑σm) for the substituent R1 were very important for antiviral activities in this class of compounds.  相似文献   

9.
Abstract

The chemical composition of Tussilago farfara L. essential oil from the Saguenay-Lac-St-Jean region of Quebec, Canada was analyzed by gas chromatography–flame ionisation detector (GC-FID) and gas chromatography–mass spectrometry (GC-MS), and the antibacterial activity of the oil was tested against Escherichia coli and Staphylococcus aureus. Forty-five (45) compounds were identified from the GC profile. The main components were 1-nonene (40.1%), α-phellandrene (26.0%) and ρ-cymene (6.6%). The essential oil demonstrated antibacterial activity against E. coli (MIC50 = 468 µg·mL?1; MIC90 = 6869 µg·mL?1) and S. aureus (MIC50 = 368 µg·mL?1; MIC90 = 773 µg·mL?1). Dodecanoic acid was found to be active against both bacteria having a MIC50 and MIC90 of 16.4 µg·mL?1 and 95 µg·mL?1, respectively for E. coli and a MIC50 and MIC90 of 9.8 µg·mL?1 and 27.3 µg·mL?1, respectively for S. aureus. In addition, 1-decene and (E)-cyclodecene were also found to be active against E. coli.  相似文献   

10.
The atmospheric corrosion of copper and silver influenced by graphite and alumina as particulate matter (PM) in an environment containing 200 μg m?3 SO2 + 150 μg m?3 NO2 at 85% RH and 25 °C was analyzed. Different proportions of PM mixture conditions were used, and the corrosion rate was followed using gravimetric analysis. Results of linear sweep voltammetry (LSV) and coulometric reduction (CR) indicated that larger corrosion rates were obtained in the presence of deposited PM. Under present exposure conditions, copper corrosion rate was larger than silver corrosion rate. X-ray diffraction (XRD) shows the presence of cuprite (Cu2O) and brochantite (Cu4SO4(OH)6) in the case of copper and achantite (Ag2S) in the case of silver.  相似文献   

11.
Hydrazinium saccharinate, N2H5+·C7H4NO3S, crystallizes in a 1:1 ratio, while ethyl­ene­diaminium bis­(saccharinate), C2H10N22+·2C7H4NO3S, and butane‐1,4‐diaminium bis­(sac­charin­ate), C4H14N22+·2C7H4NO3S, form in a 1:2 cation–anion stoichiometry. The structures contain many strong hydrogen bonds of the N+—H⋯N, N+—H⋯O, N—H⋯O and N—H⋯N types, with auxiliary C—H⋯O inter­actions.  相似文献   

12.
Microwave plasma torch (MPT), traditionally used as the light source for atomic emission spectrophotometry, has been employed as the ambient ionization source for sensitive detection of uranium in various ground water samples with widely available ion trap mass spectrometer. In the full‐scan mass spectra obtained in the negative ion detection mode, uranium signal was featured by the uranyl nitrate complexes (e.g. [UO2(NO3)3]?), which yielded characteristic fragments in the tandem mass spectrometry experiments, allowing confident detection of trace uranium in water samples without sample pretreatment. Under the optimal experimental conditions, the calibration curves were linearly responded within the concentration levels ranged in 10–1000 µg·l?1, with the limit of detection (LOD) of 31.03 ng·l?1. The relative standard deviations (RSD) values were 2.1–5.8% for the given samples at 100 µg·l?1. The newly established method has been applied to direct detection of uranium in practical mine water samples, providing reasonable recoveries 90.94–112.36% for all the samples tested. The analysis of a single sample was completed within 30 s, showing a promising potential of the method for sensitive detection of trace uranium with improved throughput. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

13.
Crystalline NO2[Fe(NO3)4] was obtained by dehydration of a solution of Fe(NO3)3 in 100 % HNO3 and subsequent sublimation. NO2[Zr(NO3)5] was synthesized by reaction of ZrCl4 with N2O5 followed by sublimation in vacuum. X‐ray single crystal structure determination showed both compounds to consist of nitronium cations, NO2+, and nitratometalate anions. N‐O distances in the linear NO2+ cations are in the range of 1.08—1.13Å. In both [Fe(NO3)4] and [Zr(NO3)5] anions, all nitrate groups are coordinated bidentately with average M‐O distances 2.134 and 2.293Å, respectively. Taking into account the position of N atoms around the M atoms, the arrangement of nitrate groups can be described as tetrahedral for the Fe complex and trigonal‐bipyramidal for the Zr complex. There are four shortest N(nitronium)····O(nitrate group) contacts with average distances of 2.705 and 2.726Å in NO2[Fe(NO3)4] and 2.749Å in NO2[Zr(NO3)5]. Nitronium pentanitratohafnate is isotypic to the zirconium complex.  相似文献   

14.
Amantadine (AMA) is an anti‐viral drug used in apiculture to protect honeybee against the sacbrood virus (Morator aetatulae). This study described a reliable high‐performance liquid chromatographic (HPLC) method for analyzing AMA in honey using a solid‐phase extraction (SPE) cartridge (Plexa PCX) for purification, 4‐fluoro‐7‐nitro‐2,1,3‐benzoxadiazole (NBD‐F) as a pre‐column derivatization agent, and fluorometric detection (λex=470 nm, λem=530 nm). The chromatographic separation was performed on an XDB C18 column (150×4.6 mm i.d.) using 0.1% trifluoroacetic acid/acetonitrile (35:65,V/V) as the mobile phase at a flow rate of 1.0 mL·min−1 with a run time of 20 min. Under these optimal conditions, a linear relationship was observed in the range of 0.025–1.0 µg· mL−1 with a good correlation coefficient (0.998) and low limit of detection (0.0080 µg·g−1), the recoveries were all above 90%, and the intra‐day and inter‐day precision (RSD) ranged from 3.4%–5.1%.  相似文献   

15.
We have carried out laboratory measurements of gas-phase ion-molecule-reactions of several negative ion species with propionic, butyric, glyoxylic, pyruvic, and pinonic acids. A flow reactor operating at a temperature of 293 ± 3 K and total gas pressures of 1.5 hPa, 9 hPa, or 40 hPa were used. The negative reagent ion species investigated included CO3, CO3H2O, NO3, NO3H2O, NO2, NO2H2O, and O3. The reactions were found to proceed either via proton transfer, switching, or clustering. A new proton transfer channel leading to alkylperoxy carboxylate radicals (R−H(OO·)COO) was observed for propionic, butyric, and pinonic acids.  相似文献   

16.
Summary: Anthracene sulfonic acid doped polyaniline nanomaterials were prepared through the chemical oxidative polymerisation process. Ammonium peroxydisulfate (APS) was employed as oxidant. Scanning electron microscopy (SEM) results show the resultant polyaniline (PANi) materials exhibited nanofibrillar morphology with diameter sizes less than 300 nm. Using the nanofibrillar PANI, amperometric biosensors for H2O2 and erythromycin were constructed through the drop-coating technique. Anthracene sulfonic acid (ASA) doped PANi and the test enzymes horseradish peroxidase, (HRP), or cytochrome P450 3A4, (CYP4503A4) were mixed in phosphate buffer solution before drop coating onto the electrode. The resultant biosensors displayed typical Michaelis-Menten behaviour. The apparent Michaelis-Menten constant obtained was 0.18 ± 0.01 mM and 0.80 ± 0.02 µM L−1 for the peroxide and erythromycin biosensor respectively. The sensitivity for the peroxide sensor was 3.3 × 10−3 A · cm−2 · mM−1, and the detection limit was found to be 1.2 × 10−2 mM respectively. Similarly, the sensitivity for the erythromycin sensor was in the same order at 1.57 × 10−3 A · cm−2 · mM−1 and detection limit was found to be 7.58 × 10−2 µM.  相似文献   

17.
《Analytical letters》2012,45(12):2182-2193
K[Pt(NH3)Cl3], a valuable precursor for the preparation of platinum complexes with cytostatic activity, e.g. satraplatin, picoplatin, LA-12 and cycloplatam, is currently prepared from cis-[Pt(NH3)2Cl2] or K2[PtCl4] and these are the usual impurities in the final product. A simple, selective and sensitive HPLC-UV analytical method for the determination of the purity of K[Pt(NH3)Cl3] and the quantification of the impurities has been developed and validated. The platinum complexes present in the final product were separated on a strong base ion exchange column by the gradient elution with detection at 213 nm. Intra-assay precisions for the platinum complexes respective to their ions ([PtCl4]2?, [Pt(NH3)Cl3]? and cis-[Pt(NH3)2Cl2]) were between 0.1 and 2.0% (relative standard deviation); intermediate precisions were between 1.4 and 2.0% and accuracies were between 98.6 and 101.4%. Limits of detection of [PtCl4]2?, [Pt(NH3)Cl3]? and cis-[Pt(NH3)2Cl2] were 6 µg · ml?1, 13 mg · ml?1 and 5 µg · ml?1 respectively, limits of quantification of [PtCl4]2?, [Pt(NH3)Cl3]? and cis-[Pt(NH3)2Cl2] were 51 µg · ml?1, 55 mg · ml?1 and 20 µg · ml?1 respectively.  相似文献   

18.
《Microchemical Journal》2009,91(2):93-98
Nitrogen dioxide (NO2) concentrations were used to evaluate the air quality before and after the infrastructural change of an important traffic artery in Mortsel, Antwerp (Belgium). During the reconstruction works two pairs of traffic lanes were reduced to one in each direction. Two sampling campaigns were conducted: the first one before the works in 2003 and the second one in 2005, after the road works were finished. Sampling was performed on a weekly base with the use of passive diffusion tubes on the streets, and also indoors in nearby houses. The samples were analyzed by ion chromatography, from which data the NO2 concentrations in air could be calculated. These results were compared with NO2 values from the air monitoring station 42R801 of the Flemish Environment Agency in Borgerhout, Antwerp. On the base of different NO2 concentrations, correlated well with the traffic density, sampling locations were classified into three groups as follows: 1) ‘heavily polluted’ (heavy traffic); 2) ‘moderately polluted’ (medium traffic); or 3) ‘less polluted’ (low traffic density). Sampling sites located further from the road works, enclosed to the group ‘less polluted’, showed the lowest NO2 concentrations. The highest NO2 level was found for the locations close to reconstruction works, which belonged to the group ‘heavily polluted’. The contribution of NO2 was at the same level before and after the road works. During the first campaign it ranged from 30 ± 7 µg/m3 to 71 ± 11 µg/m3 and during the second sampling it was between 36 ± 17 µg/m3 and 73 ± 17 µg/m3. These modernization works had no impact on preventing the traffic-related pollutant as NO2 and as a consequence no significant effect on the air quality in the studied region. It has been proven that the impact of traffic on the air quality is unmistakably high and simply reduction of the number of the traffic lanes, intended to discourage the traffic flow, had apparently no environmentally advantageous effect.  相似文献   

19.
Until now, although there are many examples of studying the magnetic properties of Schiff base binuclear lanthanide complexes, the relationship between the structure and magnetic properties of the complexes still is worth further investigation in order to improve the magnetic properties of Schiff base lanthanide complexes. In this work, we successfully obtained two series of binuclear Ln complexes by in situ reaction of 4-diethylaminosalicylaldehyde, benzoic hydrazide and different lanthanide salts at 80°C under solvothermal conditions, namely, [Ln2(L)3(NO3)3]·CH3CN·CH3OH·H2O [Ln = Dy ( 1 ), Ho ( 2 ), Gd ( 3 ) L = deprotonated 4-diethylamino salicylaldehyde benzoylhydrazine], [Ln2(L)4(CH3COO)]CH3COO·CH3CN [Ln = Dy ( 4 ), Ho ( 5 ), Gd ( 6 )]. The complex 1 contains three Schiff base ligands L, two Dy (III) ions, and three NO3. The ligand H1L is formed by in situ Schiff base reaction with 4-diethylaminosalicylaldehyde and benzoic hydrazide with the participation of Ln (NO3)3. When replacing Ln (NO3)3 with Ln (OAc)3, obtained three μ2-OAc bridged binuclear Ln (III) complexes. The magnetic study showed that complex 4 exhibits field-induced single-molecule magnet (SMM) behavior while complex 1 does not show any SMMs behavior. In addition, we have studied the magnetocaloric effect of complexes 3 and 6 , their maximum −ΔSm values are 21.37 J kg−1 K−1 and 15.32 J kg−1 K−1, respectively, under ΔH = 7 T and T = 2 K.  相似文献   

20.
The crystal structures of the title compounds, (S)‐1‐carboxy‐3‐(methyl­sulfanyl)­propanaminium chloride, C5H12NO2S+·Cl, and (S)‐1‐carboxy‐3‐(methyl­selanyl)­propanaminium chloride, C5H12NO2Se+·Cl, are isomorphous. The proton­ated l ‐methionine and l ‐seleno­methionine mol­ecules have almost identical conformations and create very similar contacts with the Cl anions in the crystal structures of both compounds. The amino acid cations and the Cl anions are linked viaN—H⋯Cl and O—H⋯Cl hydrogen bonds.  相似文献   

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