7 Replies Latest reply on Mar 2, 2016 4:58 AM by tmh

    Chlorinated paraffins

    riccardo.dallanese

      Does anybody have any experience with the determination of short chain chlorinated paraffins by LC-MS?

      Thanks to all!

        • Re: Chlorinated paraffins

          Hi Riccardo,

           

          I'm not experienced in this area, but I'm interested in learning more. What are such paraffins used for? Are you interested in detecting their presence in the environment, where they would be undesired pollutants? Or are you interested in characterizing them in substances used for industrial purposes?  That will help us find help for you.

           

          Thanks. - Josh

            • Re: Chlorinated paraffins
              riccardo.dallanese

              Hi Josh,

              I'm interested to detection and quantification of short chain chlorinated paraffins in leather and textile.

              The actual method is based on GC-MS/MS with EI but is impossible to distinguish between short, medium and long paraffins (short C10-C13, medium C14-C17, long C18-C21).

              The new ISO test method proposed a determination by GC-MS/MS by ECNI but the preliminary results submitted in commission is not good.

              I test new method by LC-MS and I observe an ion cluster for different type of chloroparaffins (short, medium and long) and for difference grade od chlorination

               

              The scope is the determination only short paraffins and quantification at 0.1 mg/kg

              Thank you Josh!

              Riccardo

                • Re: Chlorinated paraffins
                  tmh

                  Hi Riccardo,

                   

                  Don't have experience with these exact compounds but with quick search I found quite nice presentation. Would this one help you?

                   

                  http://www.agilent.com/cs/library/eseminars/public/Determination%20of%20Chloroparaffins%20in%20Foodstuffs%20by%20GC%20MS…

                    • Re: Chlorinated paraffins
                      riccardo.dallanese

                      Hi Tomi

                      thank you for the reply!

                      I saw this document two years ago and at the moment I use the same GC-MS procedure to test the SCCP.

                      The problem is the same MRM transition to SCCP and MCCP because the retention time is near the same!

                      With LC-MS I observed the formation of a dimer of SCCP and I saw the different cluster of chlorinated compund

                        • Re: Chlorinated paraffins
                          tmh

                          Hi Riccardo,

                           

                          I read some more on these compounds to understand their chromatography more. It seems that we're looking at mixture of alkanes containing different number of Chlorine. So we can't separate those in conventional GC as boiling point changes depending on number of attached Chlorines and we end up with chromatography looking similar to diesel/gasoline "forest".

                           

                          In this case if we want to separate SCCP/MCCP from each other, identify structure and content of Chlorine I would suggest GCxGC-EI-QTOF. Note that when detector is MS we need to use thermal modulator in order to keep column flow appropriate to detector. Other options would be exploring possibility of using Chlorine specific detector like µECD as then we can use flow modulator giving us lower instrument cost.

                           

                          Hope this helps and for more info you can read following article on GCxGC-NCI-TOF used to identify structure of these CPs.

                           

                          http://www.sciencedirect.com/science/article/pii/S0021967305009131

                          Journal of Chromatography A

                          Volume 1086, Issues 1–2, 9 September 2005, Pages 71–82

                          Characterization of polychlorinated n-alkanes using comprehensive two-dimensional gas chromatography–electron-capture negative ionisation time-of-flight mass spectrometry

                          •P. Korytára, b, , , •J. Parerac, •P.E.G. Leonardsa, •F.J. Santosc, •J. de Boera, •U.A.Th. Brinkmanb