how to check linearity of knauer uv dector 40D....?

[mohit91]

how to check linearity of knauer uv for mplc and hplc liquid Chromotography system i am getting problem uv wavelength graph which is suddenly goes down in running the system

[tom jupille]

Check with Knauer and see if they have a specific procedure for that detector. In general, inject a series of standards of known concentration covering the range of interest. That will show you the linearity of the *system*. If you want to evaluate the detector only, the procedure is similar, but simply use a syringe to pull the solutions through the flow cell of the disconnected detector. You will have to do some experimentation to choose a standard that has an absorbance maximum at a wavelength you want, and the concentration of that standard to give you reasonable absorbance values.