How do I calibrate my analytical system to quantify an analyte collected on a sorbent tube?
Whether you are carrying out pumped or diffusive sampling, it is good practice to use the same TD conditions for your calibration as for your analysis – do not vary the loading by changing the injection volume or split ratio. To get a good calibration, you should also use a number of calibration solutions extending below and above the target concentration.
Liquid standards are usually the simplest and most cost-effective way to calibrate, whereas gas standards reduce the likelihood of errors arising (particularly if your compounds of interest are more volatile than your solvent).
Markes’ Calibration Solution Loading Rig (CSLR) is suitable for the introduction of liquid- or gas-phase standards. For more advice on using the CSLR and other issues related to the use of standards, see Application Note 007.