Silica gel

relative polarity. Caffeine, the more polar molecule had a greater affinity for the polar silica gel stationary phase causing it to consistently have a lower retention factor regardless of the mobile phase. This methodology can be effectively used to distinguish and analyze the polarity various of chemical mixtures such as within medicines, inks, etc. In thin layer chromatography a stationary phase, silica gel with a glass backing, is dotted on a pencil drawn

chromatographic techniques have one principle in common; a liquid or gaseous solution of sample, called the moving phase, is passed (moved) through an adsorbent, called a stationary phase. With TLC the adsorbent of choice was one of the most common coatings, silica gel, SiO2. This compound is polar, and therefore, is frequently used in the separation of polar substances such as aldehydes, ketones, amines and carboxylic acids. On the other hand, a mixture of nonpolar solvents (petroleum ether and cyclohexane) was

FLAVANONES FROM THE WOOD OF Morus Nigra WITH CYTOTOXIC ACTIVITY FERLINAHAYATI A,*, YANA MAOLANA SYAH B , LIA DEWI JULIAWATY B, EUIS HOLISOTAN HAKIM B a Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Sriwijaya Jalan Raya Palembang Prabumulih Km 32, Ogan Ilir, South Sumatera, Indonesia 30622 b Natural Product Research Group, Department of Chemistry, Institut Teknologi Bandung Jalan Ganesha 10, Bandung, Indonesia 40132 * Corresponding author, tel/fax

solute absorbed by the absorbent (silica gel in this experiment) and the eluting solving flowing down. Since the components in the sample had different polarity and they interacted with the stationary phase and the mobile phase differently, the components would be carried by the solvent to a different extent and a separation of the components could be achieved. In this column chromatography, acetylferrocene was more polar, therefore was held by the silica gel more tightly and moved through the

separate and collect the desired compounds individually (Harborne, 1984) from the fraction during the procedure. The most popular stationary phase used in column chromatography is alumina and silica, same as thin layer chromatography. The most recommended gel used for separate the most compound is silica. Silica gel is slightly acidic and it is preferentially retained the basic compound. The type of solvent used as mobile phase can be determined from the previous experiment or literature. The sample with

Part C: Clear silica gel turned visibly green once green food dye was added. The first band within column (yellow) was collected after Nacl was added; methanol was added to the column to start the second mobile phase which extracts the second band of (blue) liquid from the remaining silica gel + green food dye solution. The column chromatography produced two beakers of blue and yellow from the green food

strength of the intermolecular forces and how they affect the compound’s polarity within the medications tested. TLC is the physical separation of a mixture into its individual components by distributing the components between a stationary phase, or silica gel; and a mobile phase, or movement of sample up the TLC plate to the solvent front. The mobile phase is considered to be non-polar, the non-polar components of the sample will travel farther up the TLC plate than the polar components that will stay

or aluminum foil, which is coated with a thin layer of adsorbent material, usually silica gel, aluminum oxide, or cellulose. This layer of adsorbent is known as the stationary phase. After the sample has been applied on the plate, a solvent or solvent mixture is drawn up the plate via capillary action (known as the mobile phase). The presence of hydroxyl groups in the adsorbent renders the surface of silica gel highly polar. Thus, polar functionality

TMS as an internal standard. Mass spectra were scanned by effecting FAB ionization at 70 eV on a JEOL-JMS-DX 303 spectrometer (Japan) equipped with direct inlet probe system. Column chromatography was performed on silica gel (60-120 mesh; Qualigen, Mumbai, India). TLC was run on silica gel G (Qualigen). Spots were visualised by exposing to iodine vapours, UV radiation, and spraying with ceric sulphate solution. The stem bark of Myrica esculenta Buch.-Ham., syn. M. nagi Hook.f. (Myricaceae) was collected

used to determine the proper solvent system for performing separations using column chromatography. TLC uses a stationary phase, usually alumina or silica, that is highly polar (standard) or non-polar (reverse phase), and a mobile phase, some solvent whose polarity you will choose. In 5.301, and in most lab applications, you will use standard phase silica plates. You will apply your reaction mixture in solution to the plate then "run" the plate by allowing a solvent (or combination of solvents) to move