Chromatography Forum

We do PCB analysis on a 5890 with two ECDs. We've been using an old Cobra A/S to do the injections, but it might need to be replaced. Dual injection autosamplers look expensive so I'm thinking about trying to split the flow from a single injection to two columns.

Would anyone who has tried this like to comment on how well it works, anything to be aware of, etc?

We did that for years on 5890s, 6890s and some old Tracors.
The Y connectors were somewhat fussy to get leak free. But the higher volume of flow in the inlets helped keep DDT breakdown in check on the nasty (fish/heavy oil) samples.

Glass Y connectors are good, but as Steve said, can be difficult to make leak free unless you are used to using such press tight unions. We use these https://www.restek.com/en/products/acce ... tors/3355/ with the vespel graphite ferrule adaptor they seal well. Usually after the first few oven cycles you need to re-tighten the nuts, but after that they stay sealed. We use them for all our dual column test, PCB, PEST, HERB, and HAA analysis.

I like to use a guard column one size larger than my analytical columns, but that is just my preference. To do that you need to order extra ferrule adaptors in the right size.