3-MCPD blog part 2: How hot we can go with inlet and can we use regular split/splitless inlet?

In my last blog, I (hopefully!) made a case that switching to split injection for analysis of 3-MCPD esters is a viable option. Now I’d like to show that if we stick to split, we can also use much higher temperatures and if we can do that, we can also use regular split/splitless inlet.

To evaluate, I used a similar approach as last time, i.e. set of calibration standards. Standards were analyzed at 120°C and 280°C with MMI inlet and at 280°C using split/splitless inlet (Figure 1).

Figure 1: Comparison of calibration curves of 3-MCPD-d5 obtained using different inlets and inlet temperatures.

Unfortunately, the data were not normalized with an internal standard, therefore, the response of second analysis (split/splitless) was higher than for the analysis with MMI due to evaporation. Nevertheless, the calibration curves from analysis using MMI inlet are almost identical for both temperatures, showing that the temperature of the inlet has little to no effect on the analysis (Fig. 1).

This means that with split injection we can use either MMI (PTV) or regular split/splitless inlet.

Next time I’ll look into how switching extraction solvents affects the analysis!