What is Chromatogram?

-


A chromatogram is the visual output of the chromatograph. 

A graphical representation of the detector response, concentration of analyte in the effluent, or other quantity use as a measure of effluent concentration versus effluent volume or time. 

In planar chromatography, chromatogram may refer to the paper or layer with the separated zones.

In the case of an optimal separation, different peaks or patterns on the chromatogram correspond to different components of the separated mixture.

Plotted on the x-axis is the retention time and plotted on the y-axis a signal (for example obtained by a spectrophotometer, mass spectrometer or a variety of other detectors) corresponding to the response created by the analytes exiting the system.

In the case of an optimal system the signal is proportional to the concentration of the specific analyte separated.

What is retention time?

Comments

Post a Comment

Popular posts from this blog

What is Retention time?

-
Image
Retention time (RT) is a measure of the time taken for a solute to pass through a chromatography column. Retention time (RT) is calculated as the time from injection to detection. The RT for a compound is not fixed as many factors can influence it even if the same instrument and column are used.  These include: The flow rate Temperature differences in the oven and column Column degradation Column length What is RRT?
Read more

What is RRT?

-
Image
Relative retention time (RRT) is the ratio of the retention time of analyte peak relative to that of another used as a reference obtained under identical conditions. RRT = (T analyte / T reference)  Wher T = Retention time As per USP Relative retention time (RRT): Also known as the “unadjusted relative retention”. Comparisons in USP–NF are normally made in terms of unadjusted relative retention, unless otherwise indicated. RRT = tR2/tR1 The symbol rG is also used to designate unadjusted relative retention values. The use of the relative retention time (RRT) reduces the effects of some of the variables that can affect the retention time. What is Retention time?
Read more

Establishment of expiry dating for chemicals, reagents, solutions, and solvents?

-
Image
Laboratory “reagents, and standard solutions,” as referenced in the CGMP regulations at 211.194, includes laboratory chemicals such as solvents (including mobile phases), dry chemicals (salts, primary standards, etc.), and solutions (buffers, acids/bases, quantitative analytical preparations, etc.), whether purchased or prepared in-house. Laboratory reagents and solutions are used in analytical tests of components, in-process materials, and finished products. If the purchased laboratory reagent or solution includes a manufacturer’s suggested "use by" or expiry date, that date should be followed. For purchased laboratory reagents and solutions without a "use by" or expiry date, FDA would expect that an assessment be conducted (literature review may be acceptable) of that specific chemical's or chemical family's stability and that an appropriate "use by" or expiry date be determined. For in-house prepared solutions, such as mobi
Read more