## Abstract Experiments with splitless injection of large volumes of aqueous samples by the overflow technique have shown that an organic coโsolvent is necessary to help the packing material (Tenax) retain the liquid. With 25โ30% propanol or 15โ20% 2โbutoxyethanol, some 800 ฮผl can be injected into
Concurrent solvent recondensation large sample volume splitless injection
โ Scribed by Paolo Magni; Thomas Porzano
- Book ID
- 102440585
- Publisher
- John Wiley and Sons
- Year
- 2003
- Tongue
- English
- Weight
- 319 KB
- Volume
- 26
- Category
- Article
- ISSN
- 1615-9306
No coin nor oath required. For personal study only.
โฆ Synopsis
Abstract
Concurrent Solvent Recondensation Large Sample Volume (CRSโLV) splitless injection overcomes the limitation of the maximum sample volume to 1โ2 ฮผL valid for classical splitless injection. It is based on control of the evaporation rate in the vaporizing chamber, utilization of a strong pressure increase in the injector resulting from solvent evaporation, and greatly accelerated transfer of the sample vapors from the injector into the inlet of an uncoated precolumn by recondensation of the solvent. The sample vapors are transferred into the column as rapidly as they are formed in the injector (concurrent transfer). 20โ50 ฮผL of liquid sample is injected with liquid band formation. The sample liquid is received by a small packing of deactivated glass wool positioned slightly above the column entrance at the bottom of the vaporizing chamber. Solvent evaporation strongly increases the pressure in the injector (auto pressure surge), provided the septum purge outlet is closed and the accessible volumes around the vaporizing chamber are small, driving the first vapors into the precolumn. Transfer continues to be fast because of recondensation of the solvent, obtained by keeping the oven temperature below the pressureโcorrected solvent boiling point. The uncoated precolumn must have sufficient capacity to retain most of the sample as a liquid. The experimental data show virtually complete absence of discrimination of volatile or high boiling components as well as high reproducibility.
๐ SIMILAR VOLUMES
## Abstract The classical vaporizing injector has been modified for splitless injection of large volumes: during solvent evaporation in the packed vaporizing chamber, the carrier gas supply is interrupted and the septum purge outlet fully opened. This prevents vapors penetrating the gas regulation
PTVsplitlessinjection cannot compete as far as simplicity, reliability, and accuracy of quantitative analysis is concerned. However, PTV splitless injection is attractive for trace analysis of samples containing high concentrations of involatile sample by-products. Maximum injection volumes are limi