Chromatography Forum

Hi All,
Anyone use the Gerstel TDU unit? Do you use the Twister bars?
What do you use them for and how do you get on?
Thanks in advance any replies!
WK

WK,

I use Twisters to characterize/quantify impurities in water (SBSE), in viscous liquids (HSSE) and air monitoring screening (HSSE).

It's relatively easy to get low detection limits even in scan mode. The SBSE is more sensitive than HSSE, but the latter is more sensitive than SPME.

The main limitations are the need of a specialized instrument (with TDS or TDU) and the polarity of your target analytes. You can check what you can trap with a Twister when you know/calculate the LogP (octanol/water partition coeficient). i.e. negative LogP gives very poor results.
And that you are limited to PDMS (for the moment there are no commercial alternatives).

I use a TDS but I'm going to get a TDU in the next months. I'll let you know how it works out.


Regards,
bhuvfe

Thanks for the info Bhuvfe!