by
mr3573 » Wed Jun 29, 2011 1:37 pm
What are you trying to analyse ?
Peter
The analysis is for possibility of some individual diens in benzene. Desired compounds and their boiling points as per MSDS are:
A:2,4 Hexadiene(mixtures of three isomer);82 C
B:1,3 Cyclohexadiene;80 C
C:1,4 Cyclohexadiene;88 C
The original method used column number 1 and 2 in series and connected by usual glass connector. In that case all three compounds appear before benzene but one isomers of A co-eluted with non aromatics presents in benzene and therefore difficult to determination.
I tried to using some combination of columns
1) One polar followed by one non polar (column 1 and 3) not only couldn’t separate isomers’ A but also component C disappeared and I noticed C completely covered by benzene big peak
2)one or two of non polar column – although column number 2 is some polar!-(i.e. column 3 or columns 3 and 2 in series) haven’t been successful.
Best combination was by three columns but in that case height of peak have not been good (25-35 uV for 10 ppm standards)
Some time age I posted question about that in forum but we have not heart cut or switch as recommended in forum.
Sorry for long explanation and not so good English!