共查询到20条相似文献,搜索用时 15 毫秒
1.
Rofouei MK Sabouri A Ahmadalinezhad A Ferdowsi H 《Journal of hazardous materials》2011,192(3):1358-1363
A facile and highly efficient method was developed for the preconcentration of the ultra trace amounts of mercury (II) ions. Octadecyl silica membrane disk was modified by the recently synthesized triazene ligand, 1,3-bis(2-ethoxyphenyl)triazene (EPT), and cold vapor atomic absorption spectrometry was used to determine the resultant preconcentrated Hg(II) ions. Solution studies with EPT and a series of metal ions were done in advance, and the results showed a strong affinity of EPT to the mercury ions. To perform solid phase extraction, various parameters such as pH of the sample, flow rates and the amount of the ligand were optimized. A linear calibration curve was obtained in the range of 0.02-1.90 μg L−1 with r2 = 0.9990 (n = 8), and the limit of detection (LOD) based on three times the standard deviation of the blank was 10.6 ng L−1. The relative standard deviation (RSD) for the determination of 0.1 μg L−1 Hg(II) found to be 2.9% while a RSD value of 1.1% was obtained for the determination of 1.0 μg L−1 Hg(II) (n = 8). The preconcentration and improvement factors were 380 and 74, respectively. The newly developed method was successfully applied to the determination of mercury ions in real water samples. 相似文献
2.
Hassan Ali Zamani Rahman KamjooMajid Mohammadhosseini Mojdeh ZaferoniZynab Rafati Mohammad Reza Ganjali Farnoush FaridbodSoraia Meghdadi 《Materials science & engineering. C, Materials for biological applications》2012,32(3):447-451
Conductometric study in acetonitrile solution shows the selectivity of PCQ toward europium ion. Therefore, a new europium PVC membrane electrode was prepared based on N-pyridine-2-carboxamido-8-aminoquinoline (PCQ) as an ion carrier. The electrode has a wide concentration range from 1.0 × 10− 2 and 1.0 × 10− 6 mol L− 1, Nernstian slope of 19.8 ± 0.3 mV per decade and a detection limit of 6.4 × 10− 7 mol L− 1. The potentiometric response is pH independent in the range of 2.4-7.4. The proposed sensor has a relatively fast response time less than 10 s and it can be used for at least 2 months without any considerable divergence in its potentials. The proposed electrode revealed good selectivity toward europium ion in comparison with variety of other metal ions. The practical utility of the electrodes has been demonstrated by their use as indicator electrodes in the potentiometric titration of Eu3 + ions with EDTA and for determination of Eu3 + ion concentration in mixtures of two and three different ions. 相似文献
3.
Hassan Ali Zamani Alihossien ImaniAli Arvinfar Fatemeh RahimiMohammad Reza Ganjali Farnoush FaridbodSoraia Meghdadi 《Materials science & engineering. C, Materials for biological applications》2011,31(3):588-592
A new selective Nd(III) sensor has been made by using N,N′-bis(quinoline-2-carboxamido)-4,5-dimethylbenzene (H2L4) as a suitable ionophore. The sensor exhibits Nernstian response to Nd(III) ions in the concentration range of 5.0 × 10− 6 to 1.0 × 10− 2 M. It displays a Nernstian slope of 19.5 ± 0.4 mV/decade in the pH range of 2.9-9.2. The proposed sensor also exhibits a fast response time of < l0 s. The detection limit of the proposed sensor is 4.8 × 10− 6 M, and it can be used over a period of 10 weeks without significant changes in its response. Furthermore, the electrode showed high selectivity toward Nd(III) ion respect to all other lanthanide ions tested. The practical utility of the sensor was demonstrated by using it as an indicator electrode in the potentiometric determination of Nd(III) ions in certified reference material and spiked water samples. 相似文献
4.
Hassan Ali Zamani Mohammad Reza Ganjali Farnoush FaridbodMasoud Salavati-Niasari 《Materials science & engineering. C, Materials for biological applications》2012,32(3):564-568
Tests performed using heptadentate Schiff's base ((tris(3-(thiophenal)propyl)amine (TTA)) toward Fe(III) ions indicated that it could be used as an Fe(III) selective ionophore to be used in a plasticized polymeric membrane sensor. The resulting sensors were found to produce a linear response range of five orders of magnitude with a slope of 19.8 ± 0.3 mV decade− 1 with a detection limit is 8.3 × 10− 9 mol L− 1. The sensor could be used in a pH window of 2.4-4.3 and the response time of the sensor was below 10 s, in addition to its very good Fe(III) selectivity over many mono-,di- and trivalent transition and heavy metal ions. The life time of the electrode was found to be at least 10 weeks. 相似文献
5.
Mahboubeh MasrourniaHassan Ali Zamani Hassan Ali MirrashidMohammad Reza Ganjali Farnoush Faridbod 《Materials science & engineering. C, Materials for biological applications》2011,31(3):574-578
Preliminary solution study shows the selectivity of di-tert-butylazodicarboxylate (TBADC) toward Fe(III) ions. Due to this selectivity, it was applied as an ionophore for construction of a Fe(III) sensor. The proposed sensor exhibits a wide linear response range with a Nerstian slope of 19.4 ± 0.4 mV decade− 1 and detection limit of 4.8 × 10− 8 mol L− 1. The sensor response is pH independent in the range of 2.3-3.4 and has a fast response time of < 10 s. It also shows very good selectivity to Fe(III) ion over many mono-,di- and trivalent transition and heavy metal ions. The life time of the electrode was at least 10 weeks. The application of the TBADC-based sensor to analysis of Fe(III) ion in a pharmaceutical formulation, and also to the monitoring of Fe(III) ion in mixtures of two, three and four different ions showed satisfactory results. 相似文献
6.
M. Ghaedi M. MontazerozohoriA. Mousavi S. KhodadoustM. Mansouri 《Materials science & engineering. C, Materials for biological applications》2012,32(3):523-529
New plasticized PVC membranes iodide selective electrodes have been prepared by incorporating bis(trans-cinnamaldehyde)1,3-propanediimine zinc(II) chloride [ZnLCl2] and bis(trans-cinnamaldehyde) 1,3-propandiimine cadmium(II) chloride [CdLCl2] on the surface of graphite disk electrodes. At optimum value of variables the proposed electrodes have selective response to iodide with respect to a number of inorganic and organic anions with near-Nernstian slopes of − 60 ± 1.9 and − 58.5 ± 1.9 mV/decade of iodide concentration over the range 1.0 × 10− 6-1.0 × 10− 1 M with detection limits of 4.0 × 10− 7 and 3.0 × 10− 7 M for the electrodes based on [ZnLCl2] and [CdLCl2], respectively. The electrodes based on both ionophores have response times of about (6 s), with stable reproducible response during 2 months, while their responses is independent of pH over the range 2.5-10.5. The proposed electrodes successfully have been applied for evaluation of iodide ion content in real samples with complicated matrices including water and pharmaceutical samples. 相似文献
7.
In this study a new hafnium selective sensor was fabricated from polyvinylchloride (PVC) matrix membrane containing neutral carrier N,N'-bis(alpha-methyl-salicylidene)-dipropylenetriamine (Mesaldpt) as a new ionophore, sodium tetraphenyl borate (NaTPB) as anionic discriminator and dioctyl phthalate (DOP) as plasticizing solvent mediator in tetrahydrofuran solvent. The electrode exhibits Nernstian response for Hf(4+) (Hafnium(IV)) over a wide concentration range (2.0 x 10(-7) to 1.0 x 10(-1)M) with the determination coefficient of 0.9966 and slope of 15.1+/-0.1 mVdecades(-1). The limit of detection is 1.9 x 10(-7)M. The electrode has a fast response time of 18s and a working pH range of 4-8. The proposed membrane shows excellent discriminating ability towards Hf(4+) ion with regard to several alkali, alkaline earth transition and heavy metal ions. It can be used over a period of 1.5 months with good reproducibility. It is successfully applied for direct determination of Hf(4+) in solutions by standard addition method for real sample analysis. 相似文献
8.
Y. Kalyan A.K. Pandey P.R. Bhagat R. Acharya V. Natarajan G.R.K. Naidu A.V.R. Reddy 《Journal of hazardous materials》2009
A color changeable optode for Hg(II) was prepared by the immobilization of a dye 4-(2-pyridylazo)resorcinol (PAR) and a liquid ion-exchanger trioctylmethylammonium chloride (Aliquat-336) in the tri-(2-ethylhexyl) phosphate plasticized cellulose triacetate matrix. Hg(II) and CH3Hg+ from aqueous samples could be quantitatively preconcentrated in this transparent optode producing a distinct color change (λmax = 520 nm) within 5 min equilibration time in bicarbonate aqueous medium or 30 min in natural water. Whereas optode sample without Aliquat-336 did not change its color corresponding to Hg–PAR complex on equilibrium with the same aqueous solution containing Hg(II) ions. The uptake of Hg(II) was found to be pH dependant with a maximum (>90%) at a pH 7.5. The uptake of ions like Cu(II), Fe(II), Zn(II) and Pb(II) was negligible in the optode where as the uptake of Cd(II) and Zn(II) ions was 10–15% at pH 7.5. The optode developed in the present work was studied for its analytical application for Hg(II) in the aqueous samples by spectrophotometry, radiotracer (203Hg), Energy Dispersive X-ray Fluorescence (EDXRF) analyses and Instrumental Neutron Activation Analysis (INAA). The minimum amount of Hg(II) required to produce detectable response by spectrophotometry, INAA and EDXRF were found to be 5.5, 1 and 12 μg, respectively. This optode showed a linear increase in the absorbance at λmax = 520 nm over a concentration range of 0.22–1.32 μg/mL of Hg(II) ions in aqueous solution for 5 min. The preconcentration of Hg(II) from large volume of aqueous solution was used to extend the lower limit of concentration range that can be quantified by the spectrophotometry of optode. It was observed that preconcentration of 11 μg Hg(II) in 100 mL (0.11 μg/mL) in aqueous samples gives a distinct color change and absorbance above 3σ of the blank absorbance. The optode developed in the present work was found to be reusable. 相似文献
9.
10.
The spectrophotometric change of a mercury (II) (Hg2+) selective small molecule chemosensor has been successfully converted into a photovoltaic response upon ligating Hg2+. The photon excitation was followed by charge separation facilitated by TiO2 and polyaniline (PANI), resulting in an electron transfer to an electrical back contact. The photoresponse of the Hg2+ selective chromophore was converted to an electron current equivalent to the amount of Hg2+ in solution. The favourable properties of a Hg2+ sensitive chemosensor was combined with the semiconductor capabilities of TiO2 to construct a sensor that is capable of generating a current in the presence of Hg2+ under illumination. A composite of the fluorescent chemosensor rhodamine 6G hydrozone derivative (RS) and PANI was immobilized on indium tin oxide (ITO) plates coated with TiO2 and subjected to photovoltammetric measurements. The photovoltammetric responses of the coated layers were investigated to determine the sensitivity and selectivity of the immobilized sensor to Hg2+ in the presence of background ions. The photo-response increased linearly with increasing Hg2+ concentration from 10 to 200 μg L−1 with a limit of quantification (LOQ) of 4 μg L−1. The pH independence for the photoresponse was limited by the TiO2 layer and was optimal between pH 6 and 7. 相似文献
11.
Mu Naushad 《Bulletin of Materials Science》2008,31(7):957-965
An inorganic cation exchanger, aluminum tungstate (AT), has been synthesized by adding 0·1 M sodium tungstate gradually into
0·1 M aluminium nitrate at pH 1·2 with continuous stirring. The ion exchange capacity for Na+ ion and distribution coefficients of various metal ions was determined on the column of aluminium tungstate. The distribution
studies of various metal ions showed the selectivity of Fe(III) ions by this cation exchange material. So, a Fe(III) ion-selective
membrane electrode was prepared by using this cation exchange material as an electroactive material. The effect of plasticizers
viz. dibutyl phthalate (DBP), dioctylphthalate (DOP), di-(butyl) butyl phosphate (DBBP) and tris-(2-ethylhexylphosphate) (TEHP), has also been studied on the performance of membrane sensor. It was observed that the membrane
containing the composition AT: PVC: DBP in the ratio 2: 20: 15 displayed a useful analytical response with excellent reproducibility,
low detection limit, wide working pH range (1–3·5), quick response time (15 s) and applicability over a wide concentration
range of Fe(III) ions from 1 × 10−7 M to 1 × 10−1 M with a slope of 20 ± 1 mV per decade. The selectivity coefficients were determined by the mixed solution method and revealed
that the electrode was selective for Fe(III) ions in the presence of interfering ions. The electrode was used for atleast
5 months without any considerable divergence in response characteristics. The constructed sensor was used as indicator electrode
in the potentiometric titration of Fe(III) ions against EDTA and Fe(III) determination in rock sample, pharmaceutical sample
and water sample. The results are found to be in good agreement with those obtained by using conventional methods. 相似文献
12.
Chuansheng CuiCaixia Xu lianyi XuJinsheng Zhao Renmin LiuJifeng Liu Qingpeng HeHuaisheng Wang 《Optical Materials》2011,33(11):1792-1799
Electrochemical copolymerization of 1,4-bis(2-thienyl)-naphthalene (BTN) and 2,2′-bithiophene (BT) is carried out in acetonitrile (ACN) containing sodium perchlorate (NaClO4) as a supporting electrolyte. Cyclic voltammetry (CV), UV-vis and FT-IR analyzes confirm that the resulting polymer is a copolymer rather than a blend or a composite of the respective homopolymers. The obtained P(BTN-co-BT) film exhibits five different colors (orange yellow, yellowish green, green, greenish blue and blue) under various potentials, revealing distinct electrochromic properties from that of the BTN homopolymer film. Maximum contrast (ΔT%) and response time of the copolymer film are measured as 32.7% and 0.59 s at 750 nm. Electrochromic device (ECD) based on P(BTN-co-BT) and poly(3,4-ethylenedioxythiophene) (PEDOT) is also constructed and characterized. This ECD shows a maximum optical contrast (ΔT%) of 24.2% in visible region with a response time of 0.32 s at 780 nm. The coloration efficiency (CE) of the device is calculated to be 308 cm2 C−1 at 780 nm. 相似文献
13.
针对碳酸二甲酯/二氧化碳(DMC/CO2)体系制备有较好分离效果的膜,选取聚乙烯亚胺(PEI)作为膜中运输二氧化碳的载体分子,有良好成膜性的聚乙烯醇作为膜的基础材料.在一般情况下,该膜对于纯二氧化碳的通量随着聚乙烯亚胺含量的增加而增大.对DMC/CO2体系的渗透通量随着聚乙烯亚胺含量的增加、压力差的提高和温度的升高而增大,分离因子随聚乙烯亚胺含量发生变化,随压力变化不大,随温度升高而降低.在30℃,压力差0.5MPa,温度20℃下,当聚乙烯亚胺含量达到40%,膜厚35μm时,分离因子为36,渗透通量为4.8g/(m2.h). 相似文献
14.
15.
以金属有机化合物(MO)四甲基锡[sn(CH_3)_4]为源物质,利用等离子体增强化学气相沉积技术,分别在单晶硅片、三氧化二铝陶瓷基片上淀积了纯净的SnO_(2-x)薄膜,对淀积的一些工艺条件,膜的结构、成分和薄膜元件的气敏性能进行了研究,并与普通PECVDSnO_(2-x)薄膜元件的气敏性能作了比较,对SnO_(2-x)膜的气敏机理作了探讨。 相似文献
16.
通过亲核取代反应制备了酚酞型聚醚砜(PES),利用浓硫酸对其磺化后得到了磺化聚醚砜(SPES),并通过核磁光谱对其结构进行了表征.将SPES与一定量的PVA溶解混合后,以聚砜超滤膜为支撑层,采用刷涂法制备了复合反渗透膜(SPES-PVA).扫描电镜照片显示该方法制备的反渗透膜表面平整,而且无缺陷.PVA的加入提高了膜的截盐率以及耐氯性.采用该方法得到的复合反渗透膜具有良好的截盐率和水通量.其中,当PVA的加入量为0.1%时,SPES-PVA-0.1复合反渗透膜对氯化钠的截盐率达到了97.8%,水通量为12.3L/(m2·h). 相似文献
17.
Cloud point extraction and flame atomic absorption spectrometry combination for copper(II) ion in environmental and biological samples 总被引:1,自引:1,他引:0
Shokrollahi A Ghaedi M Hossaini O Khanjari N Soylak M 《Journal of hazardous materials》2008,160(2-3):435-440
A cloud point extraction procedure was presented for the preconcentration of copper(II) ion in various samples. After complexation by 4-(phenyl diazenyl) benzene-1,3-diamine (PDBDM) (chrysoidine), copper(II) ions were quantitatively recovered in Triton X-114 after centrifugation. 0.5 ml of methanol acidified with 1.0 mol L−1 HNO3 was added to the surfactant-rich phase prior to its analysis by flame atomic absorption spectrometry (FAAS). The influence of analytical parameters including ligand, Triton X-114 and HNO3 concentrations, bath temperature, heating time, centrifuge rate and time were optimized. The effect of the matrix ions on the recovery of copper(II) ions was investigated. The detection limit (3S.D.b/m, n = 10) of 0.6 ng mL−1 along with preconcentration factor of 30 and enrichment factor of 41.1 with R.S.D. of 1.0% for Cu was achieved. The proposed procedure was applied to the analysis of various environmental and biological samples. 相似文献
18.
S. Anastasova M. Milanova I. Manolov T. Czeppe D. Todorovsky 《Bulletin of Materials Science》2007,30(5):511-520
The results from DSC and thermogravimetric analysis of gels produced from a mixture of tetraethoxysilane (TEOS) and octyltriethoxysilane
(OtEOS) both with and without immobilized Ru(II) tris(4,7-diphenyl-1,10-phenanthroline) dichloride as well as DSC and TG data for films deposited by deep-or spin-coating from
the same gels, are reported. The initial products are characterized by elemental analysis, IR, solid state NMR and mass spectroscopy.
Elemental analysis and IR spectroscopy are applied for identification of some of the intermediates obtained after heating
at different temperatures. The final products are characterized by X-ray diffractometry. A hypothesis for the thermodecomposition
processes taking place is proposed. The results reported contribute to elucidation of the properties as well as the temperature
intervals in which the studied microcomposites could be used as sensing components of oxygen sensors. 相似文献
19.
Migration of di‐(2‐ethylhexyl)adipate (DEHA) and acetyl tributyl citrate (ATBC) plasticizers from PVC film into the food stimulant of isooctane
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V. Lajqi‐Makolli M. Kerolli‐Mustafa I. Malollari J. Lajqi 《Materialwissenschaft und Werkstofftechnik》2015,46(1):16-23
Chemical migration from food packing is influenced by several factors such as nature of chemicals, complexity of food, temperature, packing material used and properties of the migrating substances. Chemical compounds that are incorporated within polymeric packaging materials may interact with food components during processing or storage and migrate into the food by jeopardizing the food safety. This migration is higher if food remains in contact with packing material for extended time. Polyvinyl chloride (PVC) film such as di‐(2‐ethylhexyl) adipate (DEHA) and acetyl tributyl citrate (ATBC) are still widely used as a food packing material due to its flexibility, transparency and low water permeability. The present study covers the main migration phenomena of both plasticizers (di‐(2‐ethylhexyl) adipate (DEHA) and acetyl tributyl citrate (ATBC)) from PVC‐film into isooctane food stimulant using a direct gas chromatographic method. An exposure period of 48 h at 30 °C and 4 °C was used. The obtained results showed DEHA levels ranging of 7.2 mg/dm2 while, no ATBC migration from PVC‐film was observed. Results are discussed in relation to EU legislation proposed upper limit for DEHA specific migration (18 mg/L or 3 mg/dm2) and overall migration limit (OM) of 10 mg/dm2. 相似文献
20.
Liu Y Liu Z Gao J Dai J Han J Wang Y Xie J Yan Y 《Journal of hazardous materials》2011,186(1):197-205
In this study, a new Pb(II) ion-imprinted polymer (Pb(II)-IIP), which can be used for selective adsorption of Pb(II) from aqueous solutions, was successfully prepared based on the supported material of ordered mesoporous silica SBA-15 with the help of surface molecular imprinting technology. The prepared polymer was characterized by Fourier transmission infrared spectrometry, X-ray diffraction, transmission electron microscope and nitrogen adsorption-desorption isotherm. The results showed that the synthesized polymer possessed high ordered mesoporous structure. The adsorption behavior of the adsorbents for Pb(II) was investigated using batch experiments. The Pb(II)-IIP showed fast kinetics, high selectivity and satisfied adsorption capacity for adsorption of Pb(II). Under the optimum experimental condition, Pb(II) adsorption process over Pb(II)-IIP follows pseudo-second-order reaction kinetics and follows the Langmuir adsorption isotherm. In addition, the thermodynamic parameters calculated from the adsorption data suggested that the adsorption of Pb(II) onto Pb(II)-IIP was a spontaneous and exothermic nature of the process. 相似文献