(GC-MS) co-eluting phthalic esthers

[A.Sanchez]

Hi, my first post here is really a scream for help...

I was assigned to develop a method to quantify contaminations of di(propylheptyl)-phthalate (DPHP) in dinonyl-phthalate (DINP) samples, and vice-versa. I´m working with a 5973N MSD coupled with a 7890A Agilent GC. The problem is that I have no experience with the MS data acquisition parameters and I´m having a hard time trying to figure it out by myself... that´s only problem number 1; problem number 2 is that I don´t even know if this quantification is possible since DINP and DPHP have the same retention times (at least with my chromatographic conditions). I guess that problem number 2 should be my first and main concern: is it possible to quantify co-eluting compounds with the 5973N MSD?

[bhuvfe]

Hi, my first post here is really a scream for help...

I was assigned to develop a method to quantify contaminations of di(propylheptyl)-phthalate (DPHP) in dinonyl-phthalate (DINP) samples, and vice-versa. I´m working with a 5973N MSD coupled with a 7890A Agilent GC. The problem is that I have no experience with the MS data acquisition parameters and I´m having a hard time trying to figure it out by myself... that´s only problem number 1; problem number 2 is that I don´t even know if this quantification is possible since DINP and DPHP have the same retention times (at least with my chromatographic conditions). I guess that problem number 2 should be my first and main concern: is it possible to quantify co-eluting compounds with the 5973N MSD?

Regarding Question N2. Yes it is possible. Using the selectivity of the MSD. Try to find an ion characteristic of DPHP and use that in SIM.

Question N1. Use the settings of a method available on Agilent's website as template. They are generally a good starting point.