薄层扫描法测定水中痕量阴离子表面活性剂

本文报告了一个可以鉴定水中痕量阴离子表面活性剂的薄层扫描法。应用大孔树脂GDX-502作为吸附剂除去干扰离子,回收率85％。乙基紫染料阳离子与阴离子表面活性剂形成紫色缔合物,用甲苯一次萃取,在硅胶G板上,应用日本岛津CS-930双波长薄层扫描仪扫描定量。提供了一个大孔树脂处理-溶剂萃取缔合物-薄层扫描分析水样中阴离子表面活性剂的方法。     

双波长薄层色谱扫描测定中参比波长的选择

在薄层色谱法定量测定中,消除或减少因薄层载板的不一致性而造成的背景噪音的方法之一是用双波长扫描法,即除样品波长(λ_S)外,选取适当的参比波长(λ_R)扫描。本文通过天麻甙薄层色谱双波长扫描(岛律CS-930薄层扫描仪)说明λ_R的选择要点。λ_S设为227nm,λ_R选取四个波长,证明:1.λ_R与λ_S在     

二维薄层扫描法分离测定人参皂甙的研究

利用二维薄层色谱技术分离了人参茎叶中的总皂甙,并首次采用标准随行法,对人参皂甙单体Ｒｅ进行了二维薄层扫描定量分析。扫描测定与数据处理由与岛津ＣＳ－９０００薄层扫描仪在线连接的３８６微机中运行的２ＤＡｎａｌｙｓｉｓ软件控制,定性鉴别于自制沉降硅胶Ｈ板上进行。将样品溶液点于板左下角,并在过该点且分别平行于两边缘的直线上（板左上方与右下方）点五种人参皂甙单体标准品的混合溶液作为一维随行对照。     

薄层色谱扫描法测定乙氧硬化醇

应用薄层色谱法测定制剂中乙氧硬化醇的含量.测定中采用CS-930型双波长薄层色谱扫描仪,将由硅胶G及羧甲基纤维素钠溶液制成的浆状液均匀涂布于色谱板上,涂布薄层的大小为10 cm×10 cm.晾干后,置于105 ℃控温的烘箱中活化30 min,用毛细管定量点样管将试样及标准的乙氧硬化醇溶液点于薄层板上,每点溶液的体积为5μL.经展开和晾干后,将试样点及标准点置于碘蒸气中显色.显色后立即取出,密封,并放置30 min后按试验方法进行单波长扫描,选择显色物的吸收峰430 nm作为测定波长.点面积的积分值和点浓度在10～50 μg/点之间呈线性关系,连续测定6次,计算测得结果的RSD值为1.28%,5次测定所得的回收率平均值为100.3%.     

薄层扫描法测定蔗糖脂肪酸酯中的各组成酯

 建立了蔗糖脂肪酸酯中一酯～三酯的薄层分离定性及薄层扫描定量方法。以氯仿 甲醇 醋酸 水 (体积比为 80∶1 0∶8∶1 )为展开剂 ,双波长反射法锯齿扫描 ,测定波长为 530nm ,参比波长为 70 0nm ,线性范围为 4μg～60 μg ,相关系数为0 9940～ 0 9980 ,平均回收率为 96 45%～ 98 73% (RSD为 2 8%～ 3 3% ,n =3)。方法可靠 ,数据准确 ,操作简便易行 ,线性范围宽。     

人参皂苷正相薄层色谱二维分离的优化

 在薄层色谱分离人参皂苷的两种互补性的流动相组分比例与皂苷比移值呈相关关系的基础上 ,以薄层色谱分离中距离最小的两点之间的距离Dmin为优化标准 ,对人参皂苷的二维分离结果进行预测和优化。通过计算机扫描不同流动相组成下的Dmin值得到的三维网络图显示出的最大Dmin下的二维流动相的组成 ,即为达到最佳二维分离结果的流动相组成。以优化的流动相对皂苷进行二维展开 ,分离结果与预测结果吻合 ,且比一维展开分离出了更多的新的皂苷组分。     

二维薄层色谱板的研制

二维薄层色谱板是在一块板上同时涂布不同吸附性能——正相和反相两种吸附剂的一种高性能的薄板,在极性和非极性溶剂中依次展开。由于它能获得更多的分离信息,可使定量分离的峰的数目大为增加,适合于分离复杂的混合物。二维薄层色谱板的概念是G.Guiocholl首先提出的。用二维技术进行复杂物质的分离,国外已有报道,国内尚末见报道。 制备分离性能良好的二维薄层色谱板的首要问题是要能分别制出正相及反相高效薄层色谱板。另一个问题就是如何把两种不同性能吸附剂很好地衔接在同一块板上     

薄层色谱扫描法测定虎杖中大黄素的含量

应用扫描薄层色谱法测定了中药虎杖中大黄素的含量,以硅胶作吸附剂的色层板作为固定相,以甲苯、乙酸乙酯及甲酸（体积比为30比4比2）的混合溶剂为展开剂。用双波长反射线性扫描对大黄素斑点进行定量检测,测定波长为440nm,参比波长为600nm。线性回归方程为y=1899．9850x＋122．9461,相关系数为0．9840,斑点峰面积的积分值与其中大黄素质量在0．40～0．81μg之间呈线性关系。在同一硅胶板上,精密地点上相同量的对照标准溶液,每个点4μL,作该方法的精密度试验,所得相对标准偏差（n=7）为0．95％。在含已知和不同量大黄素的试样中加入一定量的标准溶液作回收试验,所得结果在95．7％～99．4％之间。     

5-二甲氨基-1,2,3-三硫环己烷草酸盐的薄层色谱分析

本文用薄层色谱法以丙酮:甲醇:水:氯仿=12:3:3:5为展开剂对以盐形式存在的(这里有图片19830609-722-1.GIF)化合物进行了分析,并研究了 它的色谱行为的特殊性。通过R_f值对照法、薄层-红外光谱法对待测组分进行了鉴定。建立了双波长薄层色谱扫描碘显色外标单点校正定量法,并对不同定量方法进行了比较。测量结果相对误差和相对偏差均为±2％。     

薄层扫描法测定不同产地黑骨藤中β-香树酯醇

采用薄层扫描法测定黑骨藤药材中β-香树酯醇,并评价不同产地黑骨藤药材的质量。方法中以石油醚-氯仿(1+1.5)二元溶剂体系为展开剂,在硅胶薄层板上分离得清晰斑点,然后在536 nm波长处采用单波长线性透射扫描斑点。β-香树酯醇的质量在0.39~3.51μg范围内与其峰面积呈线性关系。在0.978,1.220,1.464μg 3个添加水平下β-香树酯醇的平均回收率分别为101.3%,96.8%,100.2%。     

负载氧化钒催化剂的多波长拉曼光谱研究:结构识别和定量

探究负载金属氧化物的结构是确立催化剂结构和催化性能之间相互关系的首要条件. 在众多表征技术中,多波长拉曼光谱结合了共振拉曼和由不同波长激发的非共振拉曼,不仅在识别负载金属氧化物团簇的结构,而且在定量方面已经成为强有力的工具. 本文以两个负载氧化钒体系(VOx/SiO2,VOx/CeO2)为例,阐述了如何利用该技术研究活性氧化物团簇的多相结构,并理解氧化物团簇和载体之间复杂的相互作用. 由多波长拉曼光谱得到的定性和定量信息能为设计更有效的负载金属氧化物催化剂提供基本的依据.     

Quantitative measurements of ammonium, hydrogenophosphate and Cu(II) by diffuse reflectance spectrometry

Diffuse reflectance spectrometry is shown to be useful for the quantitative determination of small amounts of pollutants. The relation between sample concentration and reflectance is described by the Kubelka-Munk equation. The experiments were performed with a laboratory constructed diode array spectrophotometer. We can obtain the quantitative reflectance values of different precipitates like ammonium with Nessler's reagent, hydrogenophosphate with silver nitrate and a complex such as Cu(II) with dithiooxamide 'rubeanic acid' by forming a spot colour on filter paper. We have obtained for each reagent a calibration curve by plotting the relative intensity of reflectance versus the log of the mol (dm(3))(-1) concentration. The linearity was obtained for Cu(II) from 8x10(-4) to 2.5x10(-2) mol l(-1) with r(2)=0.9838 and from 10(-3) to 10(-1) mol l(-1) for polyphosphate with r(2)=0.9975 and from 5x10(-4) to 5x10(-2) mol l(-1) for ammonium with r(2)=0.9889. We can consider that for a direct measurement of the intensity of reflectance, it is possible to perform quantitative spot-test analysis.     

多波长存储材料的合成与存储实验研究

报道了用有机光致变色的二芳基乙烯化合物作为多波长光存储记录材料的合成、膜片制作和多波长存储实验。结果显示,分别用1,2-双(2,5-二甲基噻吩-3-基)全氟环戊烯、1,2-双(2-甲基-5-醛基噻吩-3-基)全氟环戊烯和1,2-双(2-甲基-5-(2,2-二氰基乙烯基)噻吩-3-基)全氟环戊烯作为多波长光存储的记录材料,采用旋涂法(spin-coating)制成存储膜片,对应的读写激光器的波长分别532、650和780nm,实现了三波长光存储的信息记录和读出。     

Quantitative determination of drugs by in situ spectrophotometry of chromatograms for pharmacokinetic studies. I. Sulpiride and other benzamides, vincamine, naftazone (author's transl)

Assays are proposed for sulpiride and other benzamides, vincamine and naftazone in plasma (or blood) and urine with direct UV reflectance spectrophotometry on this are applied directly on TLC along with a calibration curve on each plate. Plasma (or total blood) samples are extracted, and an internal standard is added before aplication; slopes of the obtained calibration curves do not change significantly from plate to plate, thus allowing several determinations on the same plate. The sensitivity is 2 microgram in a 1-ml sample (amount applied 30 ng) for sulpiride and related compounds and about the same for vincamine. Naftazone is determined in plasma with simultaneous reflectance and transmittance spectrophotometric measurements at 520 nm on chromatoplates sprayed with lead acetate, the sensitivity reached is 10 ng in a 1-ml sample (amount applied 0.5 ng). For all drugs studied, the proposed techniques are specific, reliable and sensitive enough and can be used to perform pharmacokinetic studies in human or in animal after administration of doses in the therapeutic range.     

高效毛细管电泳－电荷耦合器件检测器联用技术研究 Ⅴ．重叠电泳峰的多元线性回归多组分分析

使用多元线性回归方法，处理电荷耦合器件多波长荧光检测毛细管电泳装置得到的三维电泳图，将在电泳时未达到有效分离、重叠严重的混合物电泳峰，分解成单个组分的电泳峰，可进行有效的定性定量分析。该法用于电泳峰完全重叠的混合罗丹明荧光染料样品，结果令人满意。     

HPTLC Method for Determination of 20-Hydroxyecdysone in Sida rhombifolia L. and Dietary Supplements

Naturally occurring 20-hydroxyecdysone is an important anabolic ecdysteroid. A simple thin-layer chromatography method to quantitate 20-hydroxyecdysone in methanolic extract of the whole plant material of Sida rhombifolia L. was developed. This method was successfully applied for quantitative evaluation of dietary supplements. The separation was achieved on glass TLC plates coated with silica gel 60F254, using chloroform: methanol (8:2 v/v) as developing solvent. Densitometric evaluation of 20-hydroxyecdysone was performed at 250 nm in reflectance/absorbance mode. The calibration was in the range of 200–1,000 ng spot^?1 and correlation coefficient for the calibration curve was >0.999. In addition, for six different Sida species unique fingerprints were obtained on the HPTLC plate.     

Evaluation of a method for high throughput solubility determination using a multi-wavelength UV plate reader

Aqueous solubility is a critical physicochemical property and must be addressed early during drug discovery research. Due to the difficulty in accurately predicting aqueous solubility in silico, high throughput experimental determination of aqueous solubility is in great demand. This study evaluates a method using a multi-wavelength UV plate reader and disposable 96-well UV plates for fast solubility determination. It was demonstrated that this method has the sensitivity and reproducibility to effectively determine solubility as low as 1 micro M. Excellent correlation (R>0.97) was observed between the solubility determined using the UV reader method and the HPLC method over the range of 1-1000 micro M for a diverse set of pharmaceutical compounds. In addition to excellent sensitivity and reproducibility, the UV plate reader method also offers the flexibility of being able to determine thermodynamic solubility in the presence or absence of dimethyl sulfoxide, which is a solvent widely used for combinatorial compounds during high throughput screening.     

Determination of Bovine Hemoglobin by Near-Infrared Diffuse Reflectance Spectroscopy with Novel Adsorption Preconcentration

A method for the quantitative determination of bovine hemoglobin in dilute solution was developed using adsorption preconcentration and near-infrared diffuse reflectance spectroscopy. An adsorbent, designated as multicarbonyl polymer-grafted silica particles, was prepared for the preconcentration of bovine hemoglobin in dilute solution. Under neutral conditions, the adsorption efficiency exceeded 98% within 20?min. After the preconcentration of bovine hemoglobin on the adsorbent, the near-infrared spectrum was measured in diffuse reflectance mode and a partial least squares model was constructed for quantitative prediction. Samples were analyzed in the presence of amino acid, albumin bovine V, D-glucose, and metal ions as potential interferences. The results show that bovine hemoglobin was selectively determined. The correlation coefficient between the predicted concentrations and the reference values was 0.9911, and the recoveries were from 86.4 to 111.2% for validation samples with concentrations between 2.1 and 30.0?mg?L^?1. Therefore, the determination of bovine hemoglobin was achieved by near-infrared diffuse reflectance spectroscopy combined with preconcentration and chemometric modeling.     

Measurement of diffuse reflectance from combinatorial samples

Using a luminescence spectrometer as a platform, a system of fibre-optic probes was created that allows full colour characterisation, fluorescence and phosphorescence spectra to be recorded in diffuse reflectance and in transmission from thick or thin film arrays of combinatorial samples of diameter down to 2 mm and from liquids. An integrating sphere is not required and the method is more versatile than the instrument's fibre-optic plate reader which has conjoined fibre bundles set at a fixed angle. Incident and detected light is routed via separate optical fibre bundles which remain stationary above or below a two-axis table. The validation and calibration are described. A library of 25 members was scanned for both diffuse reflectance (colour) and fluorescence in less than an hour. The method thus combines techniques that conventionally rely on different instruments and makes them amenable for high throughput libraries.     

Multi-wavelength HPLC fingerprint similarity metric for cold-hot nature identification of Chinese herbal medicines

Cold-hot nature theory is the core basic theory of the nature of Chinese herbal medicines (CHMs). It is found that the material basis of cold-hot nature is CHM ingredients. In view of this, our group proposed a scientific hypothesis that “CHMs with similar nature should have similar material basis”. To demonstrate this hypothesis, we developed a novel multi-wavelength high performance liquid chromatography (HPLC) fingerprint similarity metric scheme for cold-hot nature identification. We explored a multi-wavelength distance metric learning model to compute the similarity of CHM ingredients, and developed an improved k-nearest neighbor algorithm based on multi-wavelength HPLC fusion (KMHF) to predict cold-hot nature of CHMs. Firstly, multi-wavelength HPLC fingerprints were used to extract the characteristic information of CHM ingredients. Secondly, we defined the similarity of CHM ingredients as semantic relevance and fingerprint similarity. We studied a multi-wavelength distance metric to measure the similarity of CHM ingredients. The learned distance metric could discover complementary characteristics of different wavelength HPLC through an optimization algorithm. Finally, an improved multi-wavelength k-nearest neighbor algorithm KMHF was proposed to analyze the relationship between cold-hot nature and CHM ingredients. Numerous experiments were designed to test the feasibility of the proposed KMHF algorithm. Experimental results indicate that the performance of our KMHF algorithm outperforms that of the compared algorithms. Experimental results demonstrate that the hypothesis that CHMs with similar cold-hot nature have similar material basis. The KMHF model is evaluated to be feasible for nature identification.