Short Chain Chlorinated Parrafins

[stllab]

Hello.

I am looking for the best method and instrumentation for quantifying Short Chain Chlorinated Paraffins(C10-C13) in rubber hoses.

We currently run a GC/MS system but know this isn't the best route.

Please let me know any available options.

Thanks.

[chromatographer1]

An ECD will not detect alkanes but will be very sensitive to chlorinated analytes.

Headspace would be a good idea if you don't wish to extract the analytes in question.

Accuracy of measurement could be an issue.

I would extract into purified chloroform and grind the hose samples as fine as possible.

Ain't science great?

best wishes,

Rod

[AICMM]

stllab,

How chlorinated? How low do you need to go? What other stuff is in there to interfere?

If only one or two chlorine's on a C10 hydrocarbon, ECD is not really a good choice. If multiple chlorine's then ECD will get you down to very low levels. If you can use ECD then you get the advantage of not detecting other saturated hydrocarbons that may be present but if you use ECD you should extract with hexane or iso-octane.

If you only need ppm levels and the extract is relatively clean, FID for C10 hydrocarbons will get you to ppm. If not clean, then picking out the chlorinated from the non-chlorinated could be very difficult.

A Hall detector is another option, especially if only one or two chlorine's per component. However, you need to be brave enough to tackle using a Hall which few people are these days. It too gives you good selectivity although you need to be careful about coking the pyrolyzer tube (solvent vent for example.)

Not as simple an answer perhaps as you would like but things for you to consider.

Best regards,

AICMM