[curiouscat]

In order to check whether the styrene reactant for a batch reaction has been completely consumed the current protocol is to send a plant sample to the lab for a GC analysis and wait for a report from the lab.

This consumes time so we are exploring if there could be any quick alternatives that could be used. Ideas? Ideally something the operator can try in the plant itself with minimal equipment.

It doesn't need to be precise quantitatively nor have a very sensitive threshold of detection: The batches are good to go as soon as Styrene falls below 0.1%.

Is a TLC what might work? Or....?  Any reagent based spot tests?

[Dan]

TLC could work - you will be able to detect low concentrations of styrene with a permanganate stain. You'll have to compare the GC with TLC a few times to see what <0.1% looks like on TLC, and to see what complete consumption by TLC looks like by GC. You also need to standardise the concentration and volume of the TLC spot.

The limit of detection might be higher than 0.1% for TLC, but I reckon styrene + permanganate has a chance.

[curiouscat]

TLC could work - you will be able to detect low concentrations of styrene with a permanganate stain. You'll have to compare the GC with TLC a few times to see what <0.1% looks like on TLC, and to see what complete consumption by TLC looks like by GC. You also need to standardise the concentration and volume of the TLC spot.

The limit of detection might be higher than 0.1% for TLC, but I reckon styrene + permanganate has a chance.

Thanks @Dan!

Just out of curiosity, what's the cost of a basic TLC plate setup, order of magnitude. Just trying to get a rough idea  whether it would be OK or too expensive vis a vis the existing GC protocols, per test. 

[Dan]

Just out of curiosity, what's the cost of a basic TLC plate setup, order of magnitude. Just trying to get a rough idea  whether it would be OK or too expensive vis a vis the existing GC protocols, per test.

You need TLC plates, a jam jar or beaker, solvents and and reagents to make the stain. A UV lamp is useful if the plates have fluorescent indicator.

I reckon it would cost as little as 50€ to try it out, it just depends on how many and what type of plates you want to use.

I've almost always used these aluminium backed plates with fluorescent indicator. Normally the 20x20 cm sheets which we then cut down to size ourselves - but you can buy cheaper, smaller packs to test.

[DrCMS]

My advice would be to stick with the GC method; you should be able to get an accurate answer in 15-30mins.  A TLC might give you an answer in 5-10mins but will probably not give sufficient precision to say "the styrene level is 0.5% so react it further" or "the styrene is <0.1% go to the next step"