气相色谱和气相色谱/质谱法分析高级脂肪伯醇混合物的化学组分

多廿醇是从制糖滤泥中分离得到的一种高级脂肪伯醇天然混合物,其化学组成分析未见报道。本文采用气相色谱法（GC）和气相色谱／质谱法（GC／MS）,对其组分和结构进行了分析和鉴定。     

离子抑制色谱法测定棘豆属植物提取物中的苦马豆素

苦马豆素（swainsonine,SW）属吲哚兹定生物碱,是植物引起疯草中毒特征症状的唯一毒素。研究发现,SW除有毒性外,还具有很强的抗癌活性和免疫增强功能。目前其测定方法有α-甘露糖苷酶抑制分光光度法、薄层色潜扫描法、气相色谱法、液相色谱／质谱联用法等。但分光光度法样品基体干扰大,线性范围窄;薄层色谱扫描法、气相色谱法需经衍生化处理,操作繁琐。难以准确测定;液相色谱／质谱联用法仪器价格高,不易推广使用。本文建立的离子抑制色谱法分析SW,样品不经过衍生化,紫外检测器直接检测。操作简便,通用性强,为进一步研究动物疯草中毒和SW的抗癌作用奠定了基础。     

离子对色谱法测定麻杏石甘汤中的麻黄碱和伪麻黄碱

麻杏石甘汤出自《伤寒论》,由麻黄、杏仁、甘草和石膏四味中药组成。麻黄主要含麻黄碱和伪麻黄碱,两者是麻杏石甘汤中的主要有效成分。对麻黄及其制剂中的麻黄碱和伪麻黄碱含量测定的方法主要有高效液相色谱法（HPLC）、高效毛细管电泳法和气相色谱-质谱联用法等。由于麻黄碱和伪麻黄碱结构相似,而且生物碱容易产生拖尾现象,采用反相高效液相色谱法一般难以使两者达到良好的分离。本文采用反相离子对HPLC使两者获得了良好的分离,并以此法对麻杏石甘汤中的麻黄碱和伪麻黄碱进行了测定。     

非衍生气相色谱法快速测定冰醋酸中的微量甲酸

冰醋酸是最重要的有机酸之一,甲酸是冰醋酸中的主要杂质,其含量的多少直接影响冰醋酸的质量。现行国内外标准方法是利用化学方法对冰醋酸中微量的甲酸进行测定,其操作步骤繁琐,费时费力,完成测定工作约需要几个工作日,无法满足贸易结算的快速测定的需要。目前微量甲酸一般采用衍生气相色谱法测定。对甲酸直接定量测定的方法有离子色谱法、气相色谱／质谱法（GC／MS）以及气相色谱／热导检测法（TCD）。本文利用电子捕获检测器（ECD）检测甲酸,避免了衍生化或者标记方法的繁琐及化学法费时费力的缺点,而且其灵敏度远远优于TCD和氢火焰离子化检测器（FID）,同时又克服了MS检测器不易定量的缺点,为进口冰醋酸的准确快速测定提供了技术保证。     

高效液相色谱法测定大鼠心肌组织中次黄嘌呤,肌苷和腺苷含量

研究了一种快速、简便测定大鼠心肌组织中次黄嘌呤（ＨＸ）、肌苷（Ｉ）和腺苷（ＡＤＯ）的高效液相色谱法。采用ＷａｔｅｒｓμＢｏｎｄａｐａｋＣ_（１８）色谱柱，含７％甲醇的２ｍｍｏｌ／Ｌ磷酸钠缓冲液（ｐＨ＝６．０）为流动相，等比洗脱，２５４ｎｍ处紫外检测，１２ｍｉｎ内即可分析一个样品。本法生物样本预处理简单，因而平均回收率达９５％以上。ＨＸ在５．０～５００ｎｇ，Ｉ和ＡＤＯ在１０～１０００ｎｇ范围内，线性关系良好，相对标准偏差分别低于３．４０％（日内）和５．２０％（日间），并测定了３０份心肌组织中次黄嘌呤、肌苷和腺苷的含量。对所用的色谱分析条件进行了讨论。     

固相萃取富集-高效液相色谱法测定长春花中的3种内源激素

植物内源激素直接参与植物生命的所有活动。激素在植物中的含量极低,且性质不稳定,加上长春花（Catharan．thusroseus（L_）G．Don）中文多灵（vindoline）、长春质碱（catharanthine）等众多生物碱类的干扰,使得长春花植物内源激素的测定十分困难。目前对于长春花中内源激素的分离和检测尚未见报道。本文以固相萃取和高效液相色谱法测定了长春花中的3种内源激素含量,取得了理想的效果。     

铁形态分析进展

本文对Fe（Ⅱ）、Fe（Ⅲ）形态分析在1990－2000年间的发展概况作了综述，内容包括分光光度法、色谱法、流动注射分析法等。引用文献53篇。     

气相色谱-微池电子捕获检测器分析茶叶中杀螟丹的残留

介绍了一种快速、灵敏、可靠的适用于茶叶样品中杀螟丹残留量的气相色谱分析方法。茶叶样品经过0.05 mol/L盐酸溶液提取,液-液分配净化,在碱性条件下用正己烷萃取提取液中的杀螟丹,用毛细管气相色谱法-微池电子捕获检测器（μ-ECD）测定杀螟丹的残留量。结果表明：样品的添加回收率为70.2%~92.0%,相对标准偏差小于10%,方法的检测低限为0.01 mg/kg,符合农药残留分析的要求。     

PLS方法辅助TLC/FID技术测定石油沥青的族组成

测定了不同来源的渣油、不同改性工艺沥青的薄层色谱图，提取了谱图特征变量，以偏最小二乘方法为数学工具，通过经典柱色谱法取得基础数据，建立渣油沥青的薄层色谱(TLC)-族组成模型。采用该模型预测待测样品的族组成，并与经典柱色谱法的测定结果相比，饱和烃质量分数、芳烃质量分数和胶质质量分数的相关系数分别为0．9765，0．9901和0．9937。测定结果与经典柱色谱法的测定结果相一致。     

高效液相色谱法快速测定食用植物油中苯并(a)芘

采用高效液相色谱法测定食用植物油中苯并（a)芘（简称Bap）。样品经净化、溶剂抽提后,直接用高效液相色谱法测定,简便快速,安全性好,灵敏度高,线性范围宽,精确度高。最小检测量可达0．05ng。     

HEPT类化合物的QSAR研究

为定量结构／活性相关性研究提取了量子化学参数,拓扑指数Am,分子连接性指数^mxt及疏水性常数,同时应用正交变换和最佳变量子集算法（Leaps-and-Bonds)进行了变量压缩和选择,进而实施了多元回归分析,并由此结果进行了HEPT类化合物（1－[(2-hydroxyethoxy)methyl]-6-(phenylthio)-thymine derivatives)的结构／活性关系的理论解释,进行了人工神经网络法对于该类化合物的活性预测,其结构明显好于多元回归法。     

Effect of the pH of the medium on the chemical shifts in the PMR spectra and on the distribution of the π-electron density

The dependence of the chemical shifts of the ring protons on the pH of the medium for a number of 4-hydroxyquinoline derivatives was studied by means of PMR spectroscopy. The dipolar and uncharged hydroxy forms exist in equilibrium in aqueous solutions. The effect of intramolecular hydrogen bonding on the character of the dependence of the chemical shift on the pH of the medium in the case of 3-piperidinomethyl-4-hydroxyisoquinoline was investigated. The possibility of the separate protonation of the ring nitrogen and the side-chain nitrogen in 3-piperidinomethyl-4-hydroxyisoquinoline was established. The distribution of the -electron density in 4-hydroxyisoquinoline is in good agreement with its chemical behavior.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1546–1549, November, 1971     

Effect of the pH of the medium on the chemical shifts in the PMR spectra and on the distribution of the π-electron density

The dependence of the chemical shift of the ring protons on the pH of the medium for a number of 3-hydroxyquinoline derivatives was studied by PMR spectroscopy. The regions of ionization of the molecules, which correspond to the ranges of acidic, neutral, and alkaline media, were found. In D₂O, 3-hydroxyquinoline is present only in the uncharged hydroxy form. The presence of intramolecular hydrogen bonding in 4-dimethylaminomethyl-3-hydroxyquinoline has a substantial effect on the character of the dependence of the chemical shift on the pH of the medium; the existence of separate protonation of the nitrogen atoms of the ring and the side chain of 4-dimethylaminomethyl-3-hydroxyquinoline was established. The distribution of the -electron density in the 3-hydroxyquinoline molecule is in good agreement with its chemical behavior during electrophilic substitution.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1540–1545, November, 1971.     

液滴荧光传感与计算机联用技术在微量分析中的应用

通过在LS55型荧光-磷光-发光分光光度计上加装液滴产生及调节附件,采用计算机采集与分析处理数据,成功地研制了双通道液滴光化学传感装置.利用葡聚糖凝胶对复合维生素B中不同组分的选择性吸附来达到分离与同时检测的目的,并将其用于复合维生素B药片的分析,取得了满意的结果.     

On the theory underlying the Car-Parrinello method and the role of the fictitious mass parameter

The theory underlying the Car-Parrinello extended-Lagrangian approach to ab initio molecular dynamics (CPMD) is reviewed and reexamined using "heavy" ice as a test system. It is emphasized that the adiabatic decoupling in CPMD is not a decoupling of electronic orbitals from the ions but only a decoupling of a subset of the orbital vibrational modes from the rest of the necessarily coupled system of orbitals and ions. Recent work [J. Chem. Phys. 116, 14 (2002)] has pointed out that, due to the orbital-ion coupling that remains once adiabatic decoupling has been achieved, a large value of the fictitious mass mu can lead to systematic errors in the computed forces in CPMD. These errors are further investigated in the present work with a focus on those parts of these errors that are not corrected simply by rescaling the masses of the ions. It is suggested that any comparison of the efficiencies of Born-Oppenheimer molecular dynamics (BOMD) and CPMD should be performed at a similar level of accuracy. If accuracy is judged according to the average magnitude of the systematic errors in the computed forces, the efficiency of BOMD compares more favorably to that of CPMD than previous comparisons have suggested.