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Silica Gel: A non-crystalline form of silicon oxide that has absorptive properties. It is commonly used as a desiccating agent and as a stationary phase for Chromatography. The fully hydrated form of silica gel has distinct properties and is referred to as Silicic acid.

Column Chromatography

JoVE 10217

Source: Laboratory of Dr. Jimmy Franco - Merrimack College

Column chromatography is one of the most useful techniques for purifying compounds. This technique utilizes a stationary phase, which is packed in a column, and a mobile phase that passes through the column. This technique exploits the differences in polarity between compounds, allowing the molecules to be facilely separated.1 The two most common stationary phases for column chromatography are silica gel (SiO2) and alumina (Al2O3), with the most commonly used mobile phases being organic solvents.2 The solvent(s) chosen for the mobile phase are dependent on the polarity of the molecules being purified. Typically more polar compounds require more polar solvents in order to facilitate the passage of the molecules through the stationary phase. Once the purification process has been completed the solvent can be removed from the collected fractions using a rotary evaporator to yield the isolated material.


 Essentials of Organic Chemistry

Purification of a Total Lipid Extract with Column Chromatography

JoVE 10159

Source: Laboratory of Jeff Salacup - University of Massachusetts Amherst

The product of an organic solvent extraction, a total lipid extract (TLE), is often a complex mixture of hundreds, if not thousands, of different compounds. The researcher is often only interested in a handful of compounds. The compounds of interest may belong to one of several classes of compounds, such as alkanes, ketones, alcohols, or acids (Figure 1), and it may be useful to remove the compound classes to which it does not belong in order to get a clearer view of the compounds you are interested in. For example, a TLE may contain 1,000 compounds, but the Uk'37 sea surface temperature proxy is based on only two compounds (alkenones) and the TEX86 sea surface temperature proxy is based on only four (glycerol dialkyl glycerol tetraethers). It would behoove the researcher to remove as many of the compounds they are not interested in. This makes the instrumental analysis of the compounds of interest (alkenones or GDGTs) less likely to be complicated by other extraneous compounds. In other cases, an upstream purification technique may have produced compounds you wish to now remove from the sample, such as the production of carboxylic acids during saponification in our


 Essentials of Earth Science

A Detailed Protocol for Perspiration Monitoring Using a Novel, Small, Wireless Device

1Wellness Promotion Science Center, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 2Advanced Research Center for Human Sciences, Waseda University, 3Department of Clinical Laboratory Science, Graduate School of Medical Science, Kanazawa University, 4Asanogawa General Hospital

JoVE 54837


 Medicine

The Evolution of Silica Nanoparticle-polyester Coatings on Surfaces Exposed to Sunlight

1School of Science, Faculty of Science, Engineering and Technology, Swinburne University of Technology, 2BlueScope Steel Research, 3Infrared Microspectroscopy Beamline, Australian Synchrotron, 4School of Science, College of Science, Engineering and Health, RMIT University

JoVE 54309


 Engineering

Generation of a Gene-Disrupted Streptococcus Mutans Strain Without Gene Cloning

1Department of Translational Research, Tsurumi University School of Dental Medicine, 2Endowed Department of International Oral Health Science (affiliated with Department of Translational Research), Tsurumi University School of Dental Medicine, 3Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University

Video Coming Soon

JoVE 56319


 JoVE In-Press

Detection and Genogrouping of Noroviruses from Children's Stools By Taqman One-step RT-PCR

1Laboratorio de Investigación y Desarrollo (LID), Universidad Peruana Cayetano Heredia, 2Bloomberg School of Public Health, Johns Hopkins University, 3Laboratorio de Diagnostico Molecular, Facultad de Medicina, University of Concepcion,Chile, 4University of California San Diego School of Medicine

JoVE 3232


 Medicine

Preparation of Giant Vesicles Exhibiting Visible-light-induced Morphological Changes

1Department of Applied Chemistry, School of Applied Science, National Defense Academy of Japan, 2Department of Applied Physics, School of Applied Science, National Defense Academy of Japan, 3Department of Materials Science and Technology, Faculty of Engineering, Niigata University

Video Coming Soon

JoVE 54817


 JoVE In-Press

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