Improvement of the reproducibility of retention indices in temperature-programmed gas–liquid chromatography. Part I. DB-1 column
✍ Scribed by Árpád Tóth; Lajos Praszna
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 140 KB
- Volume
- 13
- Category
- Article
- ISSN
- 0882-5734
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✦ Synopsis
For calculation of retention indices, retention data for the n-alkane reference series has to be measured. In most cases when we analyse samples having many components, it is not possible to mix the n-alkanes into the analysed sample. When we measured the retention times of n-alkanes from separate injections the calculated retention indices showed unacceptably large random deviations under programmed temperature operations. We describe a simple correction for the retention times of the reference n-alkanes to improve the reproducibility of the retention indices. For this correction the analysed samples must contain one n-alkane identical with a member of the reference series. Using the dierences or ratios of the retention times of this one common n-alkane measured in the sample and measured separately, we can calculate normalized sets of retention times of the n-alkane series. The retention indices of the analysed solutes obtained by using these normalized retention times of the separately injected and measured reference series showed a better reproducibility than without normalizing.