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1.
水中莠去津,乙草胺残留量检测方法研究 总被引:9,自引:2,他引:7
确立了水中莠去津、乙草胺残留量检测方法。样本采用固相萃取提取净化,用气相色谱法在同一根色谱柱上分离后分别进入氮磷检测器(NPD) 、电子捕获检测器(ECD)进行检测。莠去津、乙草胺平均回收率分别为88-9% ~91-5 % 和90-7% ~96-5% ;相对标准偏差分别为9-7 % 和5-6% ;线性相关系数分别为0-989 和0-995 。 相似文献
2.
从3,16-二羟基-1-硫杂-5,3,11,14-四氧杂环十七烷(二羟基硫杂-17冠-5)出发,通过醚化反应,合成了双(己氧基),双(十二烷氧基)、双(十六烷氧基),双(苄氧基)和双(烯丙氧基)硫杂-17-冠-5。单己氧基、单十二烷氧基,单十六烷氧基和单苄氧基硫杂-17-冠-5作为副产物分离得到。通过二羟基硫杂-17-冠-5与丁二酰氯缩聚,合成了主链含硫杂冠醚的聚酯。 相似文献
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本文提出了在同一条件下2,(N,N-二甲基)氨基-5-甲基吡啶和2-氨基-5-甲基吡啶气相色谱分析方法。本方法以10%OV-101/Chromosorb W AW DMCS为固定相,采用程序升温法实现对3-甲基吡啶,Ⅰ,Ⅱ及其杂质的有效分离。 相似文献
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通过筛选试验,提出了从二硝基萘混合物中分离和提纯1,5-二硝基萘及1,8-二硝基萘的方法。 相似文献
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采用气相色谱法测定杀螟硫磷中的3-甲基-4-硝基苯酚和S-甲基杀螟硫磷含量,以5%OV-101固定液+ChromosordW担体作为色谱柱固定相,有较好的分离效果,满足定量要求。 相似文献
7.
采用C18反相色谱柱和紫外检测器,对2,4,5-三氟-3-甲氧基苯甲酸进行液相色谱分离,外标法定量,本方法线性范围宽,精密度好,准确度高。 相似文献
8.
以酚醛树脂为原料制备了炭支撑膜和炭-炭复合膜,研究了其气体分离性能。结果表明:炭支撑膜分离气体和机理包括努森扩散和粘性流;采用浸涂-干燥-炭化的工艺制备的炭-炭复合膜对H2/CO2具有较好的分离性能,H2/CO2分离系数达5.6,大于理想努森扩散的分离系数3.7。但在高压差时复合膜上CO2的表面扩散增强,使H2/CO2分离系数下降。 相似文献
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报道了除草剂燕麦枯中间体1-甲基-3,5-二苯基吡唑的一种新合成技术。以查耳酮为原料,经与水合肼缩合、关环制得3,5-二苯基吡唑啉,后经钯催化脱氢制取3,5-二苯基吡唑,后者在相转移催化剂存在下甲基化得到目标化合物。本研究的关键是中间体勿需分离,具有操作简便,收率高(总收率>75%),易于实现工业化生产的特点 相似文献
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本文采用8-羟基喹啉-5-磺酸(HQS)为柱前衍生试剂,用含有10mmol·L-1的四丁基溴化铵(TBA+Br-)、7.5×10-5mol·L-1的EDTA和20mmol·L-1的pH5.6乙酸-乙酸钠缓冲溶液的甲醇-水(45:55,V/V)溶液为流动相,以C18硅烷化载体为固定相,16min内分离测定了Co(Ⅲ)、Fe(Ⅲ)、Al(Ⅲ)和Pd(Ⅱ)的HQS的配合物、信噪比为3时,检出限分别为:Co(Ⅲ)0.9ppb、Fe(Ⅲ)1.5ppb和Pd(Ⅱ)5.4ppb,方法灵敏度高,干扰少,用于测定试剂级盐酸,硝酸和中国红茶样品中的这些离子,结果良好。 相似文献
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《分离科学与技术》2012,47(17):2680-2687
A multi-element preconcentration–separation technique for metal ions is established. The procedure is based on complex formation of metal ions with Bis(2-hydroxy-1-naphtaldimine)-N-diethylentriamine (BHNDT) on nanoporous Analcime as sorbent followed by their determination using flame atomic absorption spectrometry. The effects of analytical parameters like pH, flow rates, eluent types, and sorption capacity on the recoveries of metal ions are investigated. In order to predict the extraction ability of BHNDT for different metallic ions, DFT method is used to compute the binding energies of the cations to the title Schiff base compound. The calculated binding energies are in good agreement with the observed extraction power of the Shiff-base ligand. 相似文献
12.
酮类试剂萃取分离铼的研究 总被引:13,自引:0,他引:13
简述了碱性体系中酮类试剂对铼的萃取分离研究,研究了萃取率与萃取剂用量、体系碱性浓度以及金属离子浓度等之间的关键,并比较了含氧萃取剂及酮类试剂间对铼的萃分离的能力。丙酮对铼的萃取分离已用于岩石中痕量铼的实际分析测定。 相似文献
13.
《分离科学与技术》2012,47(16):2659-2668
Abstract The authors present an application of chitosan membranes for the removal of heavy metal ions. Investigations covered membranes produced by phase inversion. Additionally, separation properties of acetylated membranes were tested. Low-viscous chitosan produced by the Sea Fisheries Institute—Poland was used in the experiments. The investigations were carried out for the transition metal ions Cr(VI), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II). A method for metal ions separation by means of chitosan membranes was proposed. The metal ions were complexed in the membrane during ultrafiltration of the solution. The separation ability of the membranes was investigated for individual metal ions and for a mixture. The effect of the pH of the solution on separation properties of membranes was determined. The concentration of metal ions was investigated by the method of inductively coupled plasma (ICP) atomic emission spectrometry. The investigations show the suitability of chitosan membranes produced by the phase inversion method for the removal of metal ions. 相似文献
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Summary The separation of various metal ions by the water-soluble N-maleyl glycine polymer in conjunction with membrane filtration was investigated. The method is based on the retention of inorganic ions by this polymer in a membrane filtration cell and subsequent separation of low-molecular-weight species from the polymer complex formed. It is shown that poly(N-maleyl glycine) can bind several metal ions in aqueous solution at pH 3. At higher pH, the water-soluble polymer can be applied to the separation and preconcentration of many metal ions. In addition, the maximum capacity values of the homopolymer for copper(II) were investigated and compared in the presence of various metal ions at different pHs. 相似文献
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《分离科学与技术》2012,47(3):387-393
Abstract A rapid method for the simultaneous solvent extraction and spectrophotometric determination of macro-amounts of hexavalent uranium with N-phenyl-benzohydroxamic acid is described. The intense blood-red colored complex thus extracted from chloroform at pH ~ 4 absorbs at around 510 nm. A clean-cut separation from many commonly occurring metal ions is easily accomplished. Effects of acidity, reagent concentration, and diverse ions on the visible absorption of the extracted complex have also been investigated. 相似文献
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介绍了含吡啶基吸附材料对金属离子、无机阴离子及有机污染物的吸附分离研究进展。吡啶环的氮原子具有较强的配位功能,能与多种金属离子形成络合物。这类吸附材料对金属离子显示出高的吸附容量和吸附选择性,其吸附金属离子后形成金属主体高分子,然后再利用金属离子与具有配位性能的无机阴离子、有机污染物通过路易斯酸-碱在水溶液中进行配体交换,从而达到吸附分离的目的。作为高分子交换配体(PLE),这类新型吸附材料将是今后发展的重点。 相似文献
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双水相体系是一种绿色环保的新型分离技术,应用领域相当广泛,是近年来的研究热点。论述了双水相体系用于萃取分离金属离子的研究现状。根据所使用萃取剂的不同分3种情况进行了论述:不添加任何萃取剂直接萃取金属离子;以无机阴离子为萃取剂,依靠金属阳离子与无机阴离子形成的阴离子配合物(螯合物)而转移到萃取相,萃取金属离子;采用有机试剂作为萃取剂,依靠金属离子与萃取剂反应形成的中性配合物(螯合物)而转移到萃取相,萃取金属离子。论述了双水相体系萃取分离金属离子的发展趋势:建立金属离子在双水相体系中分配的机理模型;双水相体系成相物质的回收及再利用;通过无机盐水化能力的差异,或者通过双水相体系的温度诱导相分离,实现无机盐的分离与常温制备;开展双水相体系萃取分离金属离子的工程研究。 相似文献
18.
N. Burham 《Desalination》2009,249(3):1199-1205
A new modified polyurethane foam using 2-aminoacetylthiophenol (AATP) was employed for selective separation, preconcentration and determination of Cd and Pb ions in different samples by flame atomic absorption spectrometry (FAAS). This new modified foam was used as an effective sorbent for the solid-phase extraction (SPE) of Cd and Pb ions from aqueous solutions from natural samples. Experimental conditions for effective separation of trace levels of the analyte ions were optimized with respect to different experimental parameters in batch process. The preconcentration factors are 167 and 250 for Pb and Cd respectively. The relative standard deviation (R.S.D.) under optimum conditions is < 10% (n = 5). The accuracy of the method was estimated by using a reference material BDH Cat no: 456422W real samples that were spiked with the analyte ions. The extraction isotherm of both Cd and Pb ions was obtained. This study indicated that the novel foam presents a high affinity for Cd and Pb due to the presence of good extractive sites (S, N and O) which are introduced to the foam material. The bonding of the studied metal ions by the foam is useful for the removal of metal contamination from real samples. 相似文献
19.
The simultaneous separation of various metal ions (nickel, copper, calcium, and iron) from chelating agents (EDTA and citric acid) in water streams using Nanofiltration membranes is analyzed. Assuming that multiply-charged species are highly rejected, chemical speciation computations reproduce the observed patterns of metal and ligand rejection at different pH values and concentrations. The separation of metal ions from citric acid is achieved in acidic conditions, where multiply-charged free metal ions and neutral or singly charged free chelating species are abundant. Overall, speciation studies help to evaluate the applicability of Nanofiltration for recycling chelating agents used for metal extraction. 相似文献
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The retention of various metal ions by water‐soluble poly(4‐vinylpyridine) methyl iodide in conjunction with ultrafiltration membrane was investigated. The method is based on the retention of inorganic ions by this polymer in a membrane filtration cell and subsequent separation of low‐molecular weight species from the polymer metal ion complex formed. It is shown that the polychelatogen can bind silver(I) and mercury(II) ions in aqueous solution at pH 1. At higher pH, the water‐soluble polymer can be applied to the separation and preconcentration of silver metal ions. Therefore, this polychelatogen is highly selective to Hg(II) at pH 1 with respect to metal ions such as Cd(II) and Zn(II). © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2578–2582, 2001 相似文献