Headspace Gas Chromatography in Clinical Chemistry

As can be seen from Fig. 10-2, the measured peak areas are considerably higher at 60°C than at 40°C for the same conditioning time. Temperatures higher than 60°C should not be used, as these would lead to the coagulation effect mentioned above. 

The influence of the conditioning time on the peak areas is illustrated in Fig. 10-3, which shows that a conditioning time of 10 min leads to peak areas that are considerably smaller than after 30 min. After a conditioning time of 10 min the system is in a reproducible state, but it is advantageous, especially for trace analysis, to use a longer time, as this causes the equilibrium to shift such that a higher proportion of the components under investigation is present in the gas phase. 

A method development of this kind should be carried out for every component and matrix to be investigated. 

---

Penton, Z. (1985). Headspace measurement of ethanol in blood by gas chromatography with a modified autosampler. Clinical chemistry. 31,3,439-441. 

---