Chromatography Forum

we need an application note for analysis of organic compounds in sewage sludge with a GC system.there are some components at trace levels. I saw an article that have done this with ECD detector. is it necessary to have another detectors like TCD and FID ?

we need an application note for analysis of organic compounds in sewage sludge with a GC system.there are some components at trace levels. I saw an article that have done this with ECD detector. is it necessary to have another detectors like TCD and FID ?

It will depend on which organic compound you are looking for. Chlorinated analytes respond much better on ECD, but hydrocarbons will respond to FID but respond to ECD with very little sensitivity if any at all. There really is no universal detector with maximum sensitivity for all analyte types.

To add to James' response, I've analyzed PCBs in oil / heavy hydrocarbons with an ECD and it causes a baseline rise that is difficult to remedy. A FID is great if the compound you are after contains C-H bonds. The ECD is very selective for halogens (Cl, Br, etc). TCD does not have a very low detection level but it will give a response to any compound, ie it is a universal detector.

I would also add that sewage sludge contains reduced sulfur compounds that will have a good response on the ECD. There are several removal methods that can be used, depending on your target analytes.

I would also add that sewage sludge contains reduced sulfur compounds that will have a good response on the ECD. There are several removal methods that can be used, depending on your target analytes.

We normally use copper powder that has been cleaned with acid to remove sulfur from pesticide and PCB samples, it works well and is not expensive.