I am doing the residual solvent method validation of my product by using the Head space GC. In product the solvent which is present is Methanol, MDC and triethylamine. There is no problem for the Methanol and MDC but there is problem in TEA detection. As per revised ICH guidline the limit is 5000 ppm for TEA. when i am injecting the STD the TEA peak is very broad and not in proper shape.
My GC method parameter is :-
Column: DB 624
Injector temp.- 220°C
Oven programme : 45°C (5 min. hold) increase temp. to 90°C@ 8°C/min.then increase the temp. upto 200°C @20°C (2 min. hold).
Carrier gas flow: 2.5 psi
Split ration 1:5
Runtime 18 min.
Thermo stating temp. : 85°C
Transfer line temp.: 100°C
Injection time : 0.05 min.
Standard preparation: Taking 1390µl TEA in 100 ml flask and make the volume with DMSO. Further dilute 5 ml of this solution to 100 ml with DMSO. Take 5 ml from this and fill the 20 ml headspace vial.
Sample preparation: 500 mg sample in 5 ml DMSO.
I am using this method but this method is not suitable for TEA. So kindly suggest any modification in the method or any alternate method for the TEA.