Quantitative evaluation of thin-layer chromatograms. 5. Calculation of reflectance and transmission using Markov chains

Changes of reflected and transmitted light in cases where a band lies in different sublayers of a thin-layer chromatogram are calculated by the use of Markov chains. The problem of a “random walk with absorbing barriers” is described and compared with the problem of transmission and reflectance of light in a layer of sorbent.     

磷脂的生物功能和分析方法

磷脂是所有生物膜的基本结构物质和功能物质。磷脂对膜蛋白的构象和细胞膜的流动性起着重要作用,影响着膜蛋白功能的正常发挥。分析了解生物膜的磷脂组成对研究生物膜的结构与功能是十分必要的。本文介绍了磷脂的各种分析方法,主要是薄层色谱、柱色谱、高效液相色谱和气相色谱法。     

Separation and identification of aliphatic amine derivatives with a new fluorescent reagent using high-performance liquid chromatography and thin-layer chromatography

Summary The use of 1,2-naphthoylenebenzimidazole-6-sulphochloride has been proposed as the reagent for derivatization of aliphatic amines prior to their separation, identification and quantitation both in HPLC and in TLC. The reaction of amines with this compound is quantitative and highly fluorescent derivatives are formed that provide favourable detection limits and sensitivity as compared to Dansyl derivatives of aliphatic amines. Actual detection limits achieved correspond to ca. 10^–10 mol of the amine in a spot after elution from the thin-layer plate and to ca. 5·10^–14 mol of the amine in a sample volume of 10 l injected into the liquid chromatograph. The use of this derivatization reagent offers good potential for the analysis of trace amounts of amines in environmental samples and in biological material.Presented at the 14th International Symposium on Chromatography London, September, 1982     

薄层色谱法分离烷基芳基酮肟立体异构体

我们对酮肟中间体及肟醚类拟除虫菊酯进行了分析。经核磁共振证明,酮肟中间体在生成肟醚南反应过程中其立体构型木发生变化。目前分离酮肟立体异构物的工作报道较少。我们通过薄层色谱对不同取代的具有活性的几种酮肟异构体的分离进行了探讨。 1 实验部分     

Systematic and statistical errors in quantitative evaluation in TLC and HPTLC. 1. Evaluation by graphic methods

The paper discusses errors and error propagation in respect of graphic methods in quantitative in situ measurements in TLC. An error of 0.3% is possible by measuring only peak height if optimal conditions are chosen. This is in good agreement with analysis done practically which gives errors in the order of 0.3–0.6%. If the peak area is evaluated using the approximation peak height × half width, the error is in the order of 0.6%, but in real experiments only 1.5% had been found. Systematic errors in determining peak heights are introduced by the time constant of the amplifiers and the recorder.     

TLC separation of some biologically important amino acids on pyridinium tungstoarsenate impregnated layers

Summary A satisfactory TLC separation scheme for 15 important amino acids on silica gel layers impregnated with pyridinium tungstoarsenate using isoamyl alcohol-wateracetic acid (605030) as the solvent system has been worked out. It is found that the Martin relationship is obeyed by similarly constituted amino acids. A plot of R_M vs the concentration of pyridinium ion released shows a scatter suggesting that, besides exchange properties, other factors also strongly influence the movement of amino acids.     

小檗属四种植物中生物碱的含量的薄层扫描测定

在硅胶板上用乙酸乙酯—甲醇—浓氨水(17:4:1),分离细叶小檗、粉叶小檗、金花小檗、拟豪猪刺中的药根碱、巴马亭和小檗碱,然后用岛津CS—910型双波长薄层扫描仪,在λ_s=350nm,λ_R=375nm下,用反射法作锯齿扫描,测定了上述四种药用植物中药根碱、巴马亭和小檗碱的含量。