Gas liquid chromatography involves the vaporization and injection of a sample onto the top of the chromatographer's column. After that, the sample goes through the column as a result of the flow of mobile gases, while the column itself has a stationary liquid phase that adsorbs onto an inert solid surface. At this point, several different detectors can be used, yielding different sorts of selectivity.Know More
It is important for the carrier gas to be inert chemically, and gases that are frequently used include helium, nitrogen, carbon dioxide and argon; the specific choice generally depends on the type of detector in use.
The sample should enter the column as a vapor "plug," as a slower injection of larger samples weakens resolution and broadens the band. Most commonly, a microsyringe injects sample into a vaporizer port through a rubber septum at the column head.
To create precise outcomes, it is important to control temperatures within the column within tenths of a degree, but the optimal temperature varies with the sample's boiling point. A temperature just above the average excess of the sample yields elution time ranging between two or three minutes to half an hour. Samples that have a wide boiling range tend to respond well to temperature programming.Learn more about Chem Lab
Chromatography separates the components of a mixture based on their affinity for a stationary or mobile phase. Each compound leaves the system at a different rate. The quicker a compound is flushed through, the lower its affinity for the stationary phase.Full Answer >
Reflux is a method of applying constant heat to a mixture without losing any of the liquid to evaporation. The vessel containing the chemical mixture is placed in a second vessel filled with water or oil. It is then attached to a condenser, which cools vapors back into liquid.Full Answer >
To read a graduated cylinder, look straight at the edge of the liquid at the central horizontal line of the liquid surface, read the numbered graduation below the liquid edge, count the unnumbered lines, and estimate the in-between line space. When counting unnumbered lines, take into account the scale used.Full Answer >
A measuring cylinder is used in a laboratory for measuring exact quantities of a liquid. It is also called a graduated cylinder, as it is marked with precise measurements. It is useful in the pharmacy industry, where even minute quantities of a liquid can make a difference.Full Answer >