共查询到20条相似文献,搜索用时 93 毫秒
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2,2-二(4-羟基-3-氨基)苯基丙烷的合成 总被引:7,自引:0,他引:7
在乙醇介质中,以Fe(OH)3/C为催化剂,用80%水合肼将2,2-二(4-羟基-3-硝基)苯基丙烷还原为2,2-二(4-羟基-3-氨基)苯基丙烷。产率99.0%,纯度98.5%。考察了10种金属离子对催化剂活性的影响,结果发现Pb^2 会引起催化剂中毒;Mg^2 ,Cu^2 和Zn^2 钝化了催化剂的催化活性;Ba^2 和Cr^3 不影响催化剂的活性;Al^3 ,Ni^2 ,Ti^3 和Ti^4 能活化催化剂,使反应速度加快,但它们单独使用时无催化活性。 相似文献
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Al-SBA-15介孔分子筛的合成、表征及其在苯酚叔丁基化反应中的催化性能 总被引:14,自引:0,他引:14
通过嫁接的方法合成了Al-SBA-15介孔分子筛,用X射线衍射、透射电子显微镜、低温N2吸附和NH3程序升温脱附等方法进行了表征,并研究了其在苯酚叔丁基化反应中的催化性能. 结果表明, Al-SBA-15保持了母体SBA-15高度有序的六方介孔结构,具有较强的酸性,且在苯酚叔丁基化反应中表现出比Al-MCM-41更好的催化活性和2,4-二叔丁基苯酚选择性. 相似文献
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具有环丙烷结构的化合物是一种重要的生物代谢中间体,广泛存在于许多植物霉菌和细菌等微生物体内。三元环是一种具有很好生物活性的结构单元。三元环的反应活性不仅因为它具有类似于链状双键的化学性质,同时还具有易重排的特点,例如,由三元碳环到四元碳环、五元碳环和七元碳环的扩环反应及四元碳环到三元碳环的环收缩反应,据文献报道,给体-受体同碳取代的三元环和多取代的三元环也是一种重要的合成单元。 相似文献
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电导检测离子色谱法测定多聚磷酸盐 总被引:3,自引:0,他引:3
本文探讨用离子色谱电导检测法直接分离测定多磷酸盐,确定在AS4A-SC色谱柱上分离正、焦、三聚、六偏磷酸盐混合物的最佳淋洗条件,并测定了浇铸料添加剂中多聚磷酸盐的含量。 相似文献
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《液相色谱法及相关技术杂志》2012,35(9):1407-1435
Abstract High pressure liquid chromatographic (HPLC) methods are described for the quantitative determination of polypeptides in pharmaceutical dosage forms or in synthetic and natural products. Owing to the addition of an electrolyte for the inactivation of the residual silanol groups present on the modified silica surface, hydrophobic stationary phases were found which proved to be very suitable for the analyses of polypeptides. Excellent results were obtained with tetramethyl-ammonium containing buffer systems at pH 3 in a gradient of water-methanol. Thus the polypeptides arginine-, lysine vasopressin, oxytocin, ACTH (1–24), ACTH, β-endorphin, glucagon and porcine- and bovine Insulin could be determined with coefficients of variation below 2%. 相似文献
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Oil-In-Water Microemulsion LC Determination of Pharmaceuticals Using Gradient Elution 总被引:1,自引:0,他引:1
Efficient and novel oil-in-water microemulsion HPLC (MELC) separations of a range of solutes have been performed on conventional reversed-phase HPLC columns using gradient elution. This work follows previous successful separations using isocratic oil-in-water MELC [1]. It was found that by changing certain variables, peak-peak resolution, separation selectivity, efficiency and solute retention could be manipulated. The method was compatible with very low UV detection wavelengths. A robust separation method was developed for the quantitative analysis of 2 steroids in a combination-inhaled product for asthma. The method offered similar chromatography and run time when compared with conventional HPLC modes, thus demonstrating its potential for routine use. Stability-indicating methods were developed to separate synthetic and degradative impurities from the main component peaks in 4 pharmaceutical products. The methods offered quicker analysis times and equivalent selectivity to conventional HPLC modes. In developing the separations the effect on the chromatography of varying the operating parameters was studied. 相似文献
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A model for prediding retention time of solutes undeir linear gradient elulioa conditions has been established. In this model,the theorelkal expressions under different eluflon modes were derived and tested with the retention behaviors of p-hydroxy-benzaldehyde, vanilUn, biphenyl, phenanthrene in gradient elution. With halting into account the dwell time of the instrumeatal system, the theoretically predicted retention times agreewell with those experimentally determined. 相似文献
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构建一种利用梯度淋洗离子色谱技术分析西兰花中Cl-、Br-、NO2-、NO3-、PO43-和SO42-6种无机阴离子含量的方法。梯度淋洗色谱离子体系为DIONEX Ion Pac AS11-HC(4 mm×250 mm)色谱柱,流速1.0 mL/min,抑制器电流80 mA,KOH淋洗液梯度淋洗。6种阴离子线性相关系数0.999 5~0.999 9,相对标准偏差(RSD)<2.5%,加标回收率95.7%~104%。用于检测西兰花中无机阴离子的方法灵敏度高、回收率高、可以适用于西兰花中6种阴离子精确定量分析。 相似文献
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RP-HPLC梯度洗脱法测定桑叶中芦丁和绿原酸的含量 总被引:2,自引:0,他引:2
建立了同时测定桑叶中芦丁和绿原酸含量的方法,采用Kromasil C18柱(4.6 mm×250mm,5μm),以甲醇0.5%磷酸的水溶液为流动相,梯度洗脱程序为0 min[V(甲醇) V(0.5%磷酸)=30 70]15 min[V(甲醇) V(0.5%磷酸)=30 70]20 min[V(甲醇) V(0.5%磷酸)=50 50]35 min[V(甲醇) V(0.5%磷酸=50 50];流量0.8 mL.min-1;检测波长350 nm;柱温25℃;光电二极管阵列检测器(PAD)。结果表明,芦丁线性范围为0.218~1.962μg,r=0.999 3,样品的平均加样回收率为101.3%,RSD 1.1%;绿原酸线性范围为0.654~5.886μg,r=0.999 7,样品的平均加样回收率为98.2%,RSD 1.1%;绿原酸线性范围为0.654~5.886μg,r=0.999 7,样品的平均加样回收率为98.2%,RSD1.5%。该法快速简便,专属性强,重复性好,可作为桑叶中芦丁的定量分析方法。 相似文献
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构建一种利用梯度淋洗离子色谱技术分析西兰花中Cl-、Br-、NO2-、NO3-、PO43-和SO42-6种无机阴离子含量的方法。梯度淋洗色谱离子体系为DIONEX Ion Pac AS11-HC(4 mm×250 mm)色谱柱,流速1.0 mL/min,抑制器电流80 mA,KOH淋洗液梯度淋洗。6种阴离子线性相关系数0.9995~0.9999,相对标准偏差(RSD)<2.5%,加标回收率95.7%~104%。用于检测西兰花中无机阴离子的方法灵敏度高、回收率高、可以适用于西兰花中6种阴离子精确定量分析。 相似文献
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Four pyridinium ionic liquid cations (N-ethyl-pyridinium, N-butyl-pyridinium, N-butyl-4-methyl-pyridinium, N-hexyl-pyridinium) were separated and determined by reversed phase ion-pair chromatography with ultraviolet-visible detection. The effects of ion-pair reagent, acetonitrile concentration and column temperature on the retention and separation of the cations were evaluated. Then the four pyridinium cations could be separated at baseline within 13 min. The detection limits (S/N = 3) were 0.30–0.70 mg L?1, and relative standard deviations (n = 5) for peak areas were 0.18–0.58%. The method was applied to analyze surface water with recoveries of 99.5–104.0%, which is accurate, reliable and practical. 相似文献
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反相高效液相色谱中流动相线性梯度洗脱条件下溶质保留时间预测的新方法 总被引:4,自引:2,他引:2
在计算溶质的梯度保留时间时 ,根据流动相在色谱柱内的分布规律 ,对溶质在色谱柱内的迁移距离和流动相梯度同时进行校正 ,从而建立了一种预测溶质线性梯度洗脱条件下保留时间的新方法。该方法在不同的仪器系统中 ,对于弱保留和强保留溶质在不同线性梯度洗脱条件下保留时间的预测 ,都具有良好的准确度。以 15种氨基酸和 8种苯的同系物为例 ,该方法对于弱保留溶质保留时间的预测 ,相对平均误差分别为 3 70 %和 4 90 % ,远小于文献方法得到的结果 (2 3 6 1%和 31 16 % ) ;对于强保留溶质保留时间的预测 ,相对平均误差分别为 0 2 1%和6 0 1% ,略小于文献 。 相似文献