how do we do standard calibration for triglyceride analysis

[Louise77]

Hi,

How do we do standard calibration for triglyceride (mono, di, tri) analysis?
How come my tri- recovery (in percentage) keep increasing from one run to another while mono- and di- remain constant?

[Bruce Hamilton]

We probably require more information, what samples, the derivatisation are you using, column, injection solvent/temperature, what internal standard would be helpful. Was the ratios stable before, what's the rate of change?. Etc etc.

Peaks can increase because your solvent is evaporating, the injector is volatilising more, or most likely, you injector is becoming more inert and more TAGs get through the sytem, rather than degrade in the injector. If you don't have derivatisation reagent present, then the generated FFA and MAG and DAGs don't always appear. If you are using a volatile solvent and low temperature, some TAGs could be concentrating in the injection system, but your blanks should show that.

Sorry I can't be of more help, but we really need more information.

Bruce Hamilton