What Ramp Rate should I use for Thermal Desorption (TD)?
The OPTIC inlet is used a lot for TD applications. The most common TD application is a desorption of a Tenax filled tube/liner.
After placing the TD tube, the tube should be flushed with the carrier gas. After flushing the tube can be heated. The OPTIC Inlet temperature at the moment that the TD tube is place can be around 40°C, the Tenax material will keep the trapped compounds in the tube. After flushing it is better to have a mild heating rate (5°C/sec) so compounds will leave the Tenax in a nice way and the Tenax material will not be destroyed. Also there is a maximum temperature for the trapping material, for Tenax 320 is fine.
When the LINEX is used for automatic liner exchange it is good practice to use one of the OPTIC LINEX methods.
A Splitless TD method looks like this:
The volatile compounds coming from the trapping material can be refocused on the first part of the column by the OPTIC cold trap (this is an option of the OPTIC). After trapping on the column the cold trap is heated very fast and compounds will move forward in a very sharp band, resulting in nice sharp peaks.