共查询到20条相似文献,搜索用时 187 毫秒
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选用双-(6-氧-间羧基苯磺酰基)-β-环糊精高效液相色谱(HPLC)手性柱来拆分手性除草剂甲咪唑烟酸消旋体。以醋酸-三乙胺和甲醇为流动相,在反相高效液相色谱模式(RP-HPLC)下探究流动相配比以及缓冲液pH值对甲咪唑烟酸两对映体分离的影响。在最佳条件(20 mmol/L醋酸-三乙胺缓冲液,pH值6.50,甲醇和醋酸-三乙胺的体积比为25%:75%,流动相流速0.5 mL/min,检测波长280 nm,柱温25℃)下,甲咪唑烟酸外消旋体实现了基线分离,其分离度为2.34。 相似文献
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含盐流动相损坏色谱柱原因分析 总被引:2,自引:0,他引:2
用高压液相色谱(HPLC)分析某种原料药,采用KH2PO4缓冲液(pH值6.5)和甲醇组成的流动相进行梯度洗脱时,连续损坏两根新的色谱柱。经柱外梯度洗脱模拟实验发现:流动相pH值随着有机相比例的上升而上升,最终超过色谱柱允许的pH值上限而使色谱柱损坏;同时,当有机相的比例超过80%(体积比)时,有磷酸盐晶体析出,发生堵塞,从而加重了色谱柱的损坏。所以,在梯度洗脱时,应该做柱外模拟试验,确定有机相最高比例,以保护色谱柱。 相似文献
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含盐流动相损坏色谱柱原因探讨 总被引:1,自引:0,他引:1
用高压液相色谱(HPLC)分析某种原料药的实验过程中,采用KH2PO4缓冲液(pH值6.5)和甲醇组成的流动相进行梯度洗脱时,连续损坏两根新的色谱柱。经柱外梯度洗脱模拟实验发现了原因:流动相pH值随着有机相在流动相中体积百分数的上升而上升,最终超过色谱柱允许的pH值上限而造成色谱柱的损坏;同时,当有机相的比例超过80%时,有磷酸盐晶体析出,堵塞色谱柱,这也是损坏色谱柱的另一原因。 相似文献
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Na2S2O3是湿法脱硫过程外排废液中最主要的副盐,降低Na2S2O3的生成量对绿色生产具有重要意义。首先采用Plackett-Burman实验筛选出影响Na2S2O3生成量的关键因素,即pH、单质硫浓度、温度。在此基础上运用响应曲面法,以Na2S2O3生成量为目标函数,进行三因素三水平的优化设计分析。研究结果表明,pH对Na2S2O3的影响最大,其次是温度和单质硫浓度,因子间交互作用的影响很小。得到最优的操作条件为pH 8.25,单质硫浓度0.47 g/L,温度31.80℃,PDS浓度90 mg/L,氧硫比1.2 mmol/mmol,此时Na2S2O3生成量为1.838 mmol/L。从Na2S2O3反应动力学和多硫离子的平衡反应两方面对各因素的影响规律进行了解释。最后对实际生产过程进行分析,发现实验得出的pH过低,不利于吸收过程的稳定,现有单质硫熔融分离方法不利于降低脱硫液中的单质硫含量,加速了副盐的生成等问题,对此提出了改进意见,并取得了显著效果。 相似文献
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分子印迹开管柱的制备及水产品中恩诺沙星的检测 总被引:1,自引:0,他引:1
以原位聚合法制备了恩诺沙星分子印迹开管毛细管电色谱柱,在毛细管电色谱(CEC)操作模式下,考察了流动相的种类、pH、盐离子浓度等因素对分离柱效的影响。结果表明:分子印迹开管柱对恩诺沙星和环丙沙星的选择性好。建立了通过毛细管电色谱法同时测定水产品中恩诺沙星和环丙沙星药物残留的方法。 相似文献
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以注射泵为基础,通过硬件与软件结合,研制了一种可进行梯度调节的流动相控制系统,并与石英晶体微天平联接,利用该系统对流动相中的盐浓度和pH值分别进行梯度调节,在石英晶体微天平上实时研究了牛血清蛋白(BSA)吸附洗脱的变化. 结果表明,该流动相控制系统的流量输出误差为1%,流量稳定性为1%,梯度误差为1%,均符合GB/T 26792-2011要求. 随盐浓度增大或pH值降低,BSA逐渐被洗脱,证明该流动相控制系统能精确控制和模拟复杂固液界面. 相似文献
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Three strong anion-exchange membranes (CIM QA, Q100 and HiTrap Q) were investigated for the separation of the major proteins,
which were contained in whey, such as α-Lactalbumin, BSA and β-Lactoglobulin. Experiments were performed to determine the
optimum mobile phase composition for separating the whey proteins using the standard chemicals of the proteins. The mobile
phase was buffer A (20 mM piperazine-HCl pH 6.4) and buffer B (buffer A+1 M NaCl) and the linear gradient elution changes
of salt concentration were applied. The standard chemicals of the proteins were used to investigate the optimal mobile phase
compositions with the three anion-exchange membranes. From the experimental results, it was found that HiTrap Q was the most
effective in separating whey proteins. 相似文献
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Sylwia Studziska Feiyang Li Micha Szumski Bogusaw Buszewski Michael Lmmerhofer 《International journal of molecular sciences》2022,23(23)
The aim of this research was to develop a simple and efficient ion-pair reagent-free chromatographic method for the separation and qualitative determination of oligonucleotide impurities, exemplified by synthesis of raw products of the two single strands of patisiran siRNA. The stationary phases with mixed hydrophobic/hydrophilic properties (cholesterol and alkylamide) were firstly used for this purpose with reversed-phased high-performance liquid chromatography. Several different chromatographic parameters were tested for their impact on impurities separation: type, concentration, pH of salt, as well as organic solvent type in the mobile phase. The pH was the most influential factor on the separation and signal intensities in mass spectrometry detection. Finally, the optimized method included the application of cholesterol stationary phase, with mobile phase containing 20 mM ammonium formate (pH 6.5) and methanol. It allowed good separation and the identification of most impurities within 25 min. Since not all closely related impurities could be fully resolved from the main peak in this oligonucleotide impurity profiling, two-dimensional liquid chromatography was used for peak purity determination of the target oligonucleotides. The Ethylene Bridged Hybrid (BEH) Amide column in hydrophilic interaction liquid chromatography was applied in the second dimension, allowing additional separation of three closely related impurities. 相似文献
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丙酮酸化学萃取的盐效应 总被引:3,自引:0,他引:3
以三辛胺为萃取剂,在不同离子类型及离子强度下对丙酮酸的络合萃取过程进行了研究。结果表明,在一定pH范围内,随无机离子浓度的增加,丙酮酸分配系数随盐浓度的增加而迅速降低;萃后水相pH随盐浓度的增加均有不同程度的升高,在同一离子强度下,萃取剂浓度越高,萃后水相pH上升幅度越大。红外光谱的分析结果证实了无机阴离子可能通过同离子竞争,抑制了丙酮酸根离子与络合剂的离子对缔合作用,从而降低了萃取效果。 相似文献