Analysis of Dodecylbenzene

[daniele_firenze]

What kind of column must be used to carry out the determination of a standard of dodecylbenzene by GC / MS? Up to what temperature it is necessary to arrive? Thank you!

[Consumer Products Guy]

We used a non-polar capillary such as DB-1 or DB-5 type (I don't remember if we used a high-temperature variety of column, but one could), and temperature programming. There is a very distinct elution pattern, should be able to find example in literature. We used GC-FID, not sure GCMS will provide additional information, the positional isomers will have similar patterns.

This was our starting material for the sodium dodecylbenzene sulfonate we produced for our laundry detergent manufacturing.

[GOM]

Hi Daniele

Welcome to the forum

1. Out of interest, what is your sample and reason for analysis?

2. CPG and I have done the same analysis on laundry detergents. Analysis of the Sodium dodecylbenzene sulfonate we produced for our laundry detergent manufacturing either as the raw material or after desulphonation of the NaABS.
Somewhere I have a spreadsheet for determining the mean molecular weight for what is typically a C9-C14 homologue range for this type of material

3. As CPG said use a non polar DB 1 or DB 5 or equivalent. There is a very distinctive pattern of the positional isomers if that is what you are analysing.
As he said there are examples in the literature

You would normally expect to see the 2.3,4,5 and 6 phenyl positional isomers for C12 alkyl benzene

4. To further answer your query a maximum oven temperature of 240°C is sufficient for this type of analysis

Regards

Ralph