Non-linear responses are possible due to problems in liquid chromatograph detectors or analytical methods. The linear range can be extended by carefully diluting the sample, selecting the wavelength, and good analytical methods. Check the linearity within a certain concentration range and confirm the linear correlation with different concentrations of standards.
In liquid chromatograph analysis, problems that exceed the linear range of the detector may occur, such as entering a large sample may exceed the linear range of the detector response, but sometimes the sample volume may be nonlinear within the "safe" range, then This is because the detector has attenuated its linear dynamic range. To solve this problem, only reduce the injection volume, such as dilution or small volume of the sample, try to detect within the linear dynamic range.
Loss of sample or interference from the column can also cause linear problems, which are independent of the detector. With the partial loading method, the injection volume exceeds 50% of the volume of the loop , and the amount of sample taken may vary or the degree of dilution may be non-linear.
The use of a solvent without UV absorption as the mobile phase extends the linear range and is recommended to operate with a non-absorbent mobile phase or at a wavelength where the mobile phase has no absorption. If the mobile phase itself has a strong UV absorption, although the zero return operation is performed before the injection, the detector has actually memorized a background absorption. At this time, the available detection range has been reduced, and the detector linear range lower limit is less than zero. .
Correlation of linear range of liquid chromatograph