离子色谱法测定口服电解质颗粒中阴、阳离子的含量

目的:建立离子色谱法(IC)测定口服电解质颗粒中6种阴、阳离子(氯离子、磷酸根、柠檬酸根离子、钠离子、钾离子、镁离子)含量的方法.方法:测定阴离子的色谱柱为Metrosep A Supp-5 column(250 mm×4 mm),流动相为12.8 mmol·L-1 Na2CO3,等度洗脱,柱温为30℃,流速为0.7 ...     

离子色谱法测定碳酸锂原料药中的氯化物及硫酸盐

目的:建立抑制离子色谱法测定碳酸锂原料药中氯化物及硫酸盐的含量。方法:用Thermo Ion Pac AS11(250 mm×4mm)阴离子交换柱和Ion Pac AG 11(50 mm×4 mm)保护柱,淋洗液为10 mmol·L-1氢氧化钾溶液,由自动淋洗液发生器产生,流速为1.0 ml·min-1,柱温30℃,电导池温度35℃,阴离子抑制器抑制器电流36 m A,进样量10μl。结果:氯离子及硫酸根离子在1.0~20μg·ml-1范围内线性关系良好(r分别为0.995 1,0.997 3),氯离子回收率为106.6%(RSD=2.6%,n=6),硫酸根离子回收率为100.3%(RSD=1.9%,n=6)。结论:该方法准确可靠,可用于碳酸锂原料药中氯化物及硫酸盐的测定。     

离子色谱法同时测定微晶纤维素中氯离子和硫酸根离子含量

目的 建立同时测定微晶纤维素中氯离子和硫酸根离子含量的离子色谱法.方法 色谱柱为Dionex IonPac AS19柱(250 mm×4 mm,5μm),保护柱为IonPac AG19 Guard柱(50 mm×4 mm,5μm);检测器为电导检测器,检测器温度为30℃,检测方式为抑制电导检测;以氢氧化钾为淋洗液进行分...     

离子色谱法测定维生素C注射液中草酸的含量

目的:采用离子色谱法测定维生素C注射液中草酸的含量.方法:采用Metrosep A Supp 7(250 mm×4.0 mm,5μm)为分析柱,以3.6 mmol·L-1 Na2 CO3为淋洗液,流速为1.0 ml·min-1,柱温为35℃,进样体积为20μl.检测器为电导检测器,检测方式为抑制型电导检测.结果:草酸在...     

离子色谱法测定木糖醇中氯离子、硫酸根离子和磷酸根离子及不同级别产品质量状况的评价

目的建立离子色谱法同时测定木糖醇中氯离子、硫酸根离子和磷酸根离子的含量,并评价不同级别木糖醇中氯离子、硫酸根离子和磷酸根离子含量的质量状况。方法采用Dionex IonPac AS19阴离子分析柱(4 mm×250 mm,5μm),以氢氧化钾为淋洗液梯度洗脱,流速为1.0 mL·min~(-1),标准曲线法测定。样品用超纯水溶解并稀释后直接进样。结果氯离子、硫酸根离子和磷酸根离子分别在0.01~2.0μg·mL~(-1)、0.02~6.0μg·mL~(-1)、0.05~4.0μg·m L~(-1)内线性关系良好,r分别为0.9998、0.9995和0.9995;加样回收率(n=6)分别为96.4%、93.8%、99.3%,RSD分别为1.6%、3.2%、1.4%。结论本方法操作简便、灵敏、高效,可用于同时测定木糖醇中氯离子、硫酸根离子和磷酸根离子的含量,为其质量控制提供保证。     

离子色谱法测定口服补液盐Ⅱ中枸橼酸钠的含量

目的:建立离子色谱法测定口服补液盐Ⅱ中枸橼酸钠的含量。方法:采用ICE-AS1离子排斥色谱柱(250 mm×9 mm,5μm);以0.015 mol·L-1硫酸溶液为流动相;流速为0.6 mL·min-1;检测波长为220 nm;柱温为19℃。结果:枸橼酸钠的线性范围为0.08～8.0mg·mL-1(r=0.999 9),回收率为100.2%。结论:本方法准确、简便、快速,可用于口服补液盐Ⅱ中枸橼酸钠的含量控制。     

离子对高效液相色谱法测定尿囊素乳膏中尿囊素含量

目的:改进尿囊素乳膏中尿囊素含量的测定方法,为产品质量控制提供依据.方法:采用离子对高效液相色谱法测定,色谱柱为ODS-C18柱(250mm×4.6 mm,5 μm),流动相为0.005 mol·L-1 磷酸二氢钾溶液-甲醇(100:1)(内含0.038%的庚烷磺酸钠);流速:1.0 ml·min-1;柱温:30℃;检测波长为210 nm.结果:尿囊素在10.08~40.32 μg·ml-1范围内有良好的线性关系(r=0.9999),平均回收率为99.6%(RSD=1.12%,n=9).结论:该方法准确易行,便于质量控制.     

离子色谱法测定氢氧化钠中3种典型阴离子

建立离子色谱法测定氢氧化钠中的氯离子、硫酸根离子和碳酸根离子的含量.采用DionexIonPacTMAS18柱(4mm×250 mm,7.5 μm),通过调节抑制电流,3种阴离子能够完全分离,氯离子和硫酸根离子在10～5000 ng/ml、碳酸根离子在5～100 μg/ml范围内,线性关系良好.氯离子、硫酸根离子和碳酸...     

离子色谱法测定盐酸托烷司琼中的三氟乙酸

目的建立离子色谱检测盐酸托烷司琼中三氟乙酸的方法。方法采用Ionpac AS11-HC色谱柱(4mm×250 mm)以及相应的保护柱Ionpac AG11-HC(4 mm×50 mm),淋洗液为含有4.5 mmol·L-1Na2CO3和0.8mmol·L-1Na HCO3的溶液,流速为1.2 m L·min-1,抑制电导检测,电导池温度:35℃,柱温:35℃,进样量:25μL。结果三氟乙酸和样品中其他成分能达到很好的分离;在0.261 3⁸.711 3μg·m L-1范围内具有很好的线性关系(r=0.999 9),检出限为0.086 2μg·m L-1,定量限为0.261 3μg·m L-1。结论该方法专属性强,灵敏度高,可作为盐酸托烷司琼中三氟乙酸的检测有效方法。     

离子色谱法测定盐酸平阳霉素中的氯离子

目的 建立离子色谱法测定盐酸平阳霉素中的氯离子含量,推测其成盐比例.方法 采用Dionex IonPae AS11-HC(250mm×4mm,5μm)为色谱柱,以20mmol/L氢氧化钠溶液为淋洗液,流速为1.0mL/min,柱温为30℃,检测池温度为35℃,抑制性电导检测器的抑制电流为100mA;测定3批盐酸平阳霉素中氯离子的含量,换算出盐酸含量,并进行了方法学验证.结果 在2～30μg/mL浓度范围内,氯离子溶液的峰面积与其浓度呈良好的线性关系(r=1.0000),加样回收率分别为98.6％、99.5％和99.5％;RSD分别为0.82％、0.21％和0.45％(n=3),3批盐酸平阳霉素中氯离子的含量折算成以盐酸计,平均含量为6.83％.结论 本研究建立的离子色谱法操作简单,线性范围、重复性、回收率好,能适用于测定盐酸平阳霉素中氯离子含量,进而得到平阳霉素与盐酸成盐比例为1∶3.     

氟、锂、铝离子对孕酮去极化作用的影响

为探讨孕酮致膜电位降低的机理,我们选择性应用 GS(兴奋性 G 蛋白)激动剂 F~-,钙调蛋白抑制剂 AL~(2 )和干扰磷酯酰肌醇代谢,减少胞内 Ca~(2÷)释放的 Li~ 处理卵母细胞,并观察孕酮作用。     

Agonist-activated ion channels

This paper looks at ion channels as an example of the pharmacologist's stock in trade, the action of an agonist on a receptor to produce a response. Looked at in this way, ion channels have been helpful because they are still the only system which is simple enough for quantitative investigation of transduction mechanisms. A short history is given of attempts to elucidate what happens between the time when agonist first binds, and the time when the channel opens.     

Voltage-gated ion channels

How and where simple volatile organic molecules act in the central nervous system to cause loss of consciousness and insensitivity to pain has eluded investigation; yet remarkable progress has been made recently towards identifying possible molecular targets through which the mechanism of anesthesia is tranduced. It is likely that anesthetics act by binding directly to protein targets; several possible candidates have been identified and the debate now focuses on whether general anesthesia is due to large effects at a relatively small number of critical molecular sites or due to the combined effects of small perturbations at a very large number of sites; voltage-gated ion channels are contenders for either possibility and are the subject of this review.     

Selective ion transport and ion extraction by synthetic cyclic octapeptide

Cyclic octapeptide, cyclo[Gly-L-Lys(Z)-Sar-L-Pro]₂ (CGLSP2) was synthesized as an ionophore model. Its ion-transport ability through a liquid membrane was investigated in connection with ion extractability and conformational properties. CGLSP2 transported the picrate salts of Ba²⁺ and Ca²⁺ efficiently through chloroform membrane in a U-tube (Ba²⁺> Ca²⁺ > K⁺ > Rb⁺ > Mg²⁺> Na⁺). Cyclo[Gly-L-Lys(Z)-Sar-L-Pro] or Boc-[Gly-L-Lys(Z)-Sar-L-Pro]_n-OR (n = 1 or 2; R = H or CH₃) showed a significant decrease in ion-transport ability. Extraction equilibrium constants (K_ex) of CGLSP2 with metal picrates were determined in chloroform-water system. In this case, CGLSP2/cation complexes were found to have a stoichiometry of 1:1. The K_ex sequences were Ba²+ > Ca²⁺ > Mg²⁺ and K⁺ > Rb⁺ > Na⁺, showing good agreement with the selectivity in ion transport. Conformation of CGLSP2 in chloroform (CDC1₃) was investigated by ¹H and ¹³C-n.m.r. spectroscopy. Predominant conformation takes a C₂ -symmetric structure containing two cis Lys-Sar peptide bonds. Upon complexation with Ca²⁺ in CDC1₃/CD₃CN mixture (5/3, v/v), the conformation of CGLSP2 converged into a single C₂ -symmetric one that was predominant in a free state in CDC1₃.     

GABAC receptor ion channels

1. The present review gives an overview of studies conducted on GABAC receptors over the past 10 years since the author started at the University of Sydney. It concentrates on the structure-activity relationship profiles of the receptor and how these studies were used to: (i) develop selective GABAC receptor ligands; and (ii) understand the impact of amino acid changes on GABAC receptor pharmacology and function. 2. Structure-activity relationship studies involving variations of both ligands and their receptor targets are vital to the discovery of drugs that interact selectively with particular native and mutant receptor subtypes. Such agents may be useful for treating anxiety, depression, epilepsy and memory related disorders, such as Alzheimer's disease.