建立离子色谱法同时测定高纯试剂和有机溶剂中甲胺、二甲胺、三甲胺和6种阳离子的方法。对样品处理、色谱柱类型、淋洗液梯度等条件进行优化,实现了过氧化氢、乙醇、丙酮和异丙醇样品的直接进样分析。选用Metrosep C Supp 1阳离子交换...建立离子色谱法同时测定高纯试剂和有机溶剂中甲胺、二甲胺、三甲胺和6种阳离子的方法。对样品处理、色谱柱类型、淋洗液梯度等条件进行优化,实现了过氧化氢、乙醇、丙酮和异丙醇样品的直接进样分析。选用Metrosep C Supp 1阳离子交换柱进行梯度分离,采用微填充床阳离子抑制电导检测器检测。9种待测物质的质量浓度在5~200μg/L范围内与色谱峰面积具有良好的线性关系,相关系数均大于0.999,方法检出限为0.007~0.082μg/L。样品加标回收率为80.0%~110.5%,测定结果的相对标准偏差为0.58%~3.86%(n=5)。该方法满足高纯试剂中痕量有机胺杂质和阳离子的测定要求。展开更多
This process describes a novel technique for effective trapping of “Pd” metal through resins during the process development of L-valine, 2-[(2-amino-1,6-dihydro-6-oxo-9H-purin-9-yl) methoxy] ethyl ester, and mono hy...This process describes a novel technique for effective trapping of “Pd” metal through resins during the process development of L-valine, 2-[(2-amino-1,6-dihydro-6-oxo-9H-purin-9-yl) methoxy] ethyl ester, and mono hydrochloride known as a Valacyclovir hydrochloride (1). This technique is suitable for large-scale production of 1 and it is described here Pd metal trapping by using different resins.展开更多
The structures,energetics,and infrared(IR)spectra of the cationic monomethylamine-water clusters,[(CH3NH2)(H2O)n]^+(n=1-5),have been studied using quantum chemical calculations at the MP2/6-311+G(2d,p)level.The result...The structures,energetics,and infrared(IR)spectra of the cationic monomethylamine-water clusters,[(CH3NH2)(H2O)n]^+(n=1-5),have been studied using quantum chemical calculations at the MP2/6-311+G(2d,p)level.The results reveal that the formation of protontransferred CH2NH3+ ion core structure is preferred via the intramolecular proton transfer from the methyl group to the nitrogen atom and the water molecules act as the acceptor for the O…HN hydrogen bonds with the positively charged NH3^+ moiety of CH2NH3^+,whose motif is retained in the larger clusters.The CH3NH2^+ ion core structure is predicted to be less energetically favorable.Vibrational frequencies of CH stretches,hydrogen-bonded and free NH stretches,and hydrogen-bonded OH stretches in the calculated IR spectra of the CH2NH3^+ and CH3NH2^+ type structures are di erent from each other,which would a ord the sensitive probes for fundamental understanding of hydrogen bonding networks generated from the radiation-induced chemical processes in the[(CH3NH2)(H2O)n]+complexes.展开更多
文摘建立离子色谱法同时测定高纯试剂和有机溶剂中甲胺、二甲胺、三甲胺和6种阳离子的方法。对样品处理、色谱柱类型、淋洗液梯度等条件进行优化,实现了过氧化氢、乙醇、丙酮和异丙醇样品的直接进样分析。选用Metrosep C Supp 1阳离子交换柱进行梯度分离,采用微填充床阳离子抑制电导检测器检测。9种待测物质的质量浓度在5~200μg/L范围内与色谱峰面积具有良好的线性关系,相关系数均大于0.999,方法检出限为0.007~0.082μg/L。样品加标回收率为80.0%~110.5%,测定结果的相对标准偏差为0.58%~3.86%(n=5)。该方法满足高纯试剂中痕量有机胺杂质和阳离子的测定要求。
文摘This process describes a novel technique for effective trapping of “Pd” metal through resins during the process development of L-valine, 2-[(2-amino-1,6-dihydro-6-oxo-9H-purin-9-yl) methoxy] ethyl ester, and mono hydrochloride known as a Valacyclovir hydrochloride (1). This technique is suitable for large-scale production of 1 and it is described here Pd metal trapping by using different resins.
基金the National Natural Science Foundation of China(No.21673231,No.21673234,No.21688102,and No.21873097)the Strategic Priority Research Program of the Chinese Academy of Sciences(CAS)(No.XDB17000000)+1 种基金Dalian Institute of Chemical Physics(DICP DCLS201702)China Postdoctoral Science Foundation(No.2018M641718 and No.2018M641719).
文摘The structures,energetics,and infrared(IR)spectra of the cationic monomethylamine-water clusters,[(CH3NH2)(H2O)n]^+(n=1-5),have been studied using quantum chemical calculations at the MP2/6-311+G(2d,p)level.The results reveal that the formation of protontransferred CH2NH3+ ion core structure is preferred via the intramolecular proton transfer from the methyl group to the nitrogen atom and the water molecules act as the acceptor for the O…HN hydrogen bonds with the positively charged NH3^+ moiety of CH2NH3^+,whose motif is retained in the larger clusters.The CH3NH2^+ ion core structure is predicted to be less energetically favorable.Vibrational frequencies of CH stretches,hydrogen-bonded and free NH stretches,and hydrogen-bonded OH stretches in the calculated IR spectra of the CH2NH3^+ and CH3NH2^+ type structures are di erent from each other,which would a ord the sensitive probes for fundamental understanding of hydrogen bonding networks generated from the radiation-induced chemical processes in the[(CH3NH2)(H2O)n]+complexes.
