What is the limit for tailing factor in HPLC?
Acceptable Tailing In practical terms, an As value below 1.5 is usually OK to work with, and up to As = 2.0 may be acceptable depending on the separation and resolution of the peaks. If the As value is greater than 2.0, then there is a problem that needs to be identified and fixed.
What is the importance of tailing factor in HPLC?
Symmetrical peaks with tailing factor of 1( this is the ideal tailing factor of course) results in accurate intergration of the peak area and also peak hight specailly in quantitative analysis.
How do you improve tailing factor in HPLC?
There are a few methods that can be used to avoid peak tailing:
- Operate at a lower pH.
- Use a highly deactivated column.
- Consider the possibility of mass overload.
- Consider the possibility of column bed deformation.
- Work at high pH when analyzing basic compounds.
- Use a sample clean-up procedure.
What is tailing effect in chromatography?
Tailing is basically the inverse of fronting. The peak is presented asymmetrically, with a broader second half and a narrower first half – breaking away from the ideal peak shape, with its symmetrical Gaussian profile. While the effect is similar, the circumstances of tailing are different from those of fronting.
How do you calculate tailing?
The tailing factor is determined by drawing a perpendicular line from the peak centre to the baseline of the peak. Then the peak width and the front half-width are measured for the peak at 5% of the height of the peak. The tailing factor is simply the entire peak width divided by twice the front half-width.
What is the formula of tailing factor?
It is calculated using the following equation: Tf = (a+b)/2a where a is the distance from the leading edge of the peak to the peak midpoint (perpendicular from the peak highest point) measured at 5% of peak height and b is the distance from the peak midpoint (perpendicular from the peak highest point) to the trailing …
How can the GC tailing factor be reduced?
Adopting regular column trimming and inlet liner maintenance into preventative maintenance schedule will help enormously to reduce the instances of peak tailing through secondary retention effects.
What is a tailing factor?
The tailing factor is simply the entire peak width divided by twice the front half-width. For a perfectly Gaussian peak, the front half-width will be exactly half the entire peak width, so the tailing factor will be 1.0.
What factors affect HPLC peak tailing?
What Factors Affect HPLC Peak Tailing? Ionized silanols will ion-exchange with protonated bases which can cause tailing and method variability. This occurs most often at mid pH where silanols are ionized. Unprotonated acids can compete for H + with protonated silanols; this can occur at low pH.
What is the USP tailing factor?
USP Tailing Factor – at 5% of peak height* Asymmetry – at 10% of peak height Indicators Efficiency – plates* Peak Width – peak width at ½ height
What is the width of the peak in HPLC?
W 0.05 is the Width of the peak determined at 5% from the baseline of the peak height f is the distance between peak maximum and peak front at W 0.05 What Factors Affect HPLC Peak Tailing?
How do you find the tailing factor?
The tailing factor is measured as: T=b/a a represents the width of the front half of the peak, b is the width of the back half of the peak. The values are measured at 10 % of the peak height from the leading or trailing edge of the peak to a line dropped perpendicularly from the peak apex (see Fig. 5). [4]