Search results
Results from the WOW.Com Content Network
Gram staining is almost always the first step in the identification of a bacterial group. While Gram staining is a valuable diagnostic tool in both clinical and research settings, not all bacteria can be definitively classified by this technique. This gives rise to gram-variable and gram-indeterminate groups.
In chemical analysis, chromatography is a laboratory technique for the separation of a mixture into its components. The mixture is dissolved in a fluid solvent (gas or liquid) called the mobile phase, which carries it through a system (a column, a capillary tube, a plate, or a sheet) on which a material called the stationary phase is fixed ...
Thus, different components of the mixture move at different speed. Different components of a mixture can therefore be identified by their respective R ƒ values, which is the ratio between the migration distance of the substance and the migration distance of the solvent front during chromatography. In combination with the instrumental methods ...
These terms are derived from the idea that a homogeneous mixture has a uniform appearance, or only one phase, because the particles are evenly distributed. However, a heterogeneous mixture has constituent substances that are in different phases and easily distinguishable from one another. In addition, a heterogeneous mixture may have a uniform ...
Typical uses of GC include testing the purity of a particular substance, or separating the different components of a mixture. [1] In preparative chromatography, GC can be used to prepare pure compounds from a mixture. [2] [3] Gas chromatography is also sometimes known as vapor-phase chromatography (VPC), or gas–liquid partition chromatography ...
Paper chromatography is one method for testing the purity of compounds and identifying substances. Paper chromatography is a useful technique because it is relatively quick and requires only small quantities of material. Separations in paper chromatography involve the principle of partition.
Different compounds in the sample mixture travel at different rates due to the differences in their partition coefficients. [10] Different solvents, or different solvent mixtures, gives different separation. [5] The retardation factor (R f), or retention factor, quantifies the results. It is the distance traveled by a given substance divided by ...
A separation process is a method that converts a mixture or a solution of chemical substances into two or more distinct product mixtures, [1] a scientific process of separating two or more substances in order to obtain purity. At least one product mixture from the separation is enriched in one or more of the source mixture's constituents.