Dear Redskytonight820;
Like ETOX I prefer the GC-MS combination, because you have both at once: Concentration and ‘Identification’.
If ‘Accumulation’ in Concentration (e.g. from Headspace) is required, also as micro extraction, think about a “Cool-Trap” on the in-let for better Separation and deeper “Detection Limits”!
Good Luck!
ARGOS++