Head space technique

[GT]

Dear all,
we will buy a new head space with 6890GC equipped with FID from Agilent for determination of residual solvents in drug substance.
I'm new in this technique so I've a lot of questions about this:
can I use nitrogen as carrier gas or Helium is better ?
which is the best column for this application ?
Is it necessary to use a safe pre-column ?
Any other advice from you (and your experience) will be appreciate.
Thanks

[chromatographer1]

1. You can use nitrogen carrier but helium is better.

2. The best column is the most durable, the least length, the least cost, that will perform the separation you require.

3. The Supelco SPB-1301 or equilavent is a good general purpose column that separates a great number of solvents well and quickly.

4. Generally with daily use, a column will last 6mo to a year. I have used a short Carbowax column ahead of the primary column use adjust the selectivity of the analysis and to protect the primary column. See my article in Analytical Chemistry Vol.69, No. 11, p2221-3 for details.