Dynamic gas extraction carried out stepwise, with sequential analysis of a number of headspace samples taken from the same vial.
Notes: - At equilibrium the headspace is sampled and the remainder (or most of it) is exhausted and replaced by fresh gas phase. The process is repeated and the original sample concentration estimated from the peak areas for two consecutive extractions. \[A_{\rm{T}} = \frac{A_{1}^{2}}{A_{1} - A_{2}}\] where \(A_{\rm{T}}\) = estimated sum of all partial peak areas corresponding to exhaustive extraction, \(A_{1}\) the peak area obtained from the first headspace fraction, and \(A_{2}\) the peak area obtained in the second (consecutive) headspace fraction.
- External calibration is required to convert peak areas into sample concentration.
Source:
PAC, 2016, 88, 517. 'Glossary of terms used in extraction (IUPAC Recommendations 2016)' on page 529 (https://doi.org/10.1515/pac-2015-0903)