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291.
Solubilities of CO2 in aqueous solutions of activated methyldiethanolamine (MDEA) has been investigated for temperatures and CO2 partial pressures ranging from 40 to 80°C and 0.1 to 100~kPa, respectively. Piperazine (PZ) is used as activator, with a concentration ranging from 0.01 to 0.1~M, keeping the amine total concentration in the aqueous solution at 2~M. The experimental solubility results were represented by the mole ratio of CO2 per activated amine present in the liquid mixture. The addition of piperazine, as activator for MDEA, increased the solubility of CO2 in the region of low CO2 partial pressure compared to pure MDEA. The CO2 loading increased with decreasing temperature, increasing CO2 partial pressure, and increasing PZ concentration.  相似文献   
292.
293.
In this study, we developed a novel, simple, rapid, and low-cost colloidal gold-based immunochromatography method, with filter paper replacing nitrocellulose membrane as the substrate. To obtain adequately immobilized protein, chitosan was used to functionalize the filter paper. After conditions and parameters were optimized, the novel immunochromatography method was applied for detection of sulfonamide residues in milk. Quantitative detection was accomplished using a smartphone and Photoshop software (Adobe Inc., San Jose, CA), allowing us to screen 13 sulfonamides with a limit of detection ranging from 0.42 to 8.64 μg/L and recovery ranging from 88.2 to 116.9% in milk. The proposed novel method performed similarly to the conventional method that uses a nitrocellulose membrane as the transport medium, and it had lower cost and better usability because of the inexpensive and easily available filter paper.  相似文献   
294.
在常规酶联免疫法的基础上,将磺胺类母核与牛血清白蛋白合成免疫抗原后免疫小鼠制得磺胺类单克隆抗体,并进一步优化抗体工作浓度、反应时间等实验参数,建立了一种简便、快速、精确的磺胺类残留一步式化学发光酶联免疫检测方法.结果表明该方法最佳检测范围为1.0~81.0 ng/mL,检测IC50达3.047 ng/mL,对猪肉的最低检测限为0.74 ng/g,可检出国际规定的SAs残留标准底限值以下的残留量.与常规ELISA方法相比,检测限和灵敏度基本一致,但反应时间缩短了60 min.证明采用一步式化学发光酶联免疫检测磺胺类残留可以大幅度缩减检测时间,符合快速检测的要求.  相似文献   
295.
多沙唑嗪中间体的手性分离方法优化研究   总被引:1,自引:0,他引:1  
多沙唑嗪是一种抗高血压手性药物,1-(1,4-苯并二口恶烷-2-羰基)哌嗪(BCP)是合成该药物的重要手性中间体。手性多沙唑嗪的光学纯度可以通过BCP的光学纯度来控制。该文采用柱前衍生化-反相高效液相色谱法优化了BCP的手性分离方法,以便对其进行光学纯度检测。结果表明:以乙酰葡萄糖异硫氰酸酯(G ITC)为柱前手性衍生化试剂,C18柱(4.6 mm×250 mm)为色谱柱,可以将BCP对映体分离,优化的其他色谱条件为:流动相组成V(CH3OH)∶V〔c(KH2PO4的水溶液)=0.02 mol/L〕=50∶50,流速0.6 mL/m in,检测波长250 nm。在选择的测定条件下,BCP与G ITC形成的非对映异构体达到基线分离,分离度约等于1.5(R=1.5),在2~250μg.mL-1内,非对映体的色谱峰面积与质量浓度之间线性相关系数大于0.998。  相似文献   
296.
提出以甲苯为共沸剂去除混合溶液中的乙二胺和结晶水的间歇共沸精馏法,最后得到质量分数为96.79%的哌嗪及98.26%三乙烯二胺产品,并以水为萃取剂,实现共沸剂的回收利用。采用Aspen Plus化工模拟软件对精馏分离过程进行模拟计算,设计了4塔精馏分离及共沸剂回收的工业化实验装置,利用灵敏度分析模块对精馏塔各操作参数进行优化,从而获得质量分数分别为98.60%和99.20%的哌嗪和三乙烯二胺产品。  相似文献   
297.
Solubility correlations are of great importance in the design of industrial carbon dioxide capture processes. Nevertheless, the development of this correlations are rarely used in the design of industrial control systems. The main objective of this work is to provide the basis for using solubility correlations in fast dynamic systems for industrial model based control applications.  相似文献   
298.
Polyvinylamine (PVAm) was modified using a cross‐linking agent containing carriers piperazine (PIP). Attenuated total reflectance fourier transform infrared, elemental analyzer, and X‐ray diffraction were used to characterize the PIP‐modified PVAm. The PVAm–PIP/polysulfone (PS) composite membrane was developed by coating PVAm–PIP mixed solutions with different mass ratios of PIP/PVAm (mPIP/mPVAm) on the PS ultrafiltration membrane. The effects of mPIP/mPVAm (from 0.715 to 2.860) in the coating solutions and wet coating thickness on the gas performance of the PVAm–PIP/PS composite membrane were investigated. The PVAm–PIP/PS composite membrane prepared showed higher performance than other membranes reported in the literature due to the large increase of the introducing carrier concentration and low crystallinity. Moreover, the separation performance stability of the PVAm–PIP/PS composite membrane was investigated and no deterioration in the membrane permselectivity was observed. Finally, the economic evaluation of the membrane with the highest performance prepared was carried out. © 2012 American Institute of Chemical Engineers AIChE J, 59: 215–228, 2013  相似文献   
299.
《精细化工》2005,22(5):392-394
1 (1, 4 苯并二口恶烷2 羰基)哌嗪是制备抗高血压药物多沙唑嗪的重要中间体,手性多沙唑嗪可以通过中间体的手性分离来制备。用柱前衍生化-反相高效液相色谱法对1 (1, 4 苯并二口恶烷2 羰基)哌嗪对映体进行了分离。结果表明,用乙酰葡萄糖异硫氰酸酯(GITC)为柱前手性衍生化试剂,C18柱(4 6mm×250mm)为色谱柱,可以将1 (1, 4 苯并二口恶烷2 羰基)哌嗪对映体分离,其他色谱条件为:流动相组成为V(甲醇)∶V(0 02mol/L磷酸二氢钾水溶液) = 53∶47,流速为0 5mL/min,检测波长为250nm。在选择的测定条件下,非对映异构体分离度约等于1 3(R=1 3)。  相似文献   
300.
The process of removing dilute CO2 from air by using me mixtures of K2CO3 and piperazine (PZ) was conducted in a random packed tower at 25℃. The results showed that PZ increased the absorption rate of CO2 into aqueous K2 CO3 much more effectively than MEA or DEA. The volumetric overall mass transfer coefficient (KGa) of dilute CO2 absorption into K2CO3/PZ was measured. The KGa value was evaluated over the ranges of main operating variables: the concentration of CO2 in inlet gas, gas flow rate, liquid loading, CO2 loading in liquid phase, and the concentrations of K2CO3 and PZ. The test showed that KGa could be remarkably improved by increasing liquid loading and the concentration of PZ, and decreasing the concentration of CO2 in inlet gas, as well as the gas flow rate and CO2 loading in liquid phase.  相似文献   
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