Large volume splitless injection with concurrent solvent recondensation: Keeping the sample in place in the hot vaporizing chamber

Abstract

An injector liner packed with a plug of glass wool is compared with a laminar and a mini laminar liner for large volume (20-50 microL) splitless injection with concurrent solvent recondensation (CSR-LV splitless injection). Videos from experiments with perylene solutions injected into imitation injectors show that glass wool perfectly arrested the sample liquid and kept it in place until the solvent had evaporated. The sample must be transferred from the needle to the glass wool as a band, avoiding 'thermospraying' by partial solvent evaporation inside the needle. The liquid contacted the liner wall when the band was directed towards it, but from there it was largely diverted to the glass wool. In the laminar liners, part of the liquid remained and evaporated at the entrance of the obstacle, while the other proceeded to the center cavity. Vapors formed in the center cavity drove liquid from the entrance of the obstacle upwards, but the importance of such problems could not be verified in the real injector. Some liquid split into small droplets broke through the obstacle and entered the column. Breakthrough through the laminar liners was confirmed by a chromatographic experiment. An improved design of a laminar liner for large volume injection is discussed as a promising alternative if glass wool causes problems originating from insufficient inertness.

Argentation high performance liquid chromatography on-line coupled to gas chromatography for the analysis of monounsaturated polyolefin oligomers in packaging materials and foods

“…For matrices including a high proportion of involatile hydrocarbons (polyolefin extracts), transfer involved a PTV injector as a kind of filter for the involatile material. Concurrent solvent recondensation in the precolumn was applied to accelerate the transfer into the column and reconcentrate the initial bands of the volatiles by solvent trapping [20,21]. During transfer, the carrier gas (hydrogen) inlet pressure was 90 kPa.…”

“…In a preliminary overview, 11 polyolefin granulates (PE: n = 8; PP: n = 3) contained 5-40% (average 25%) POMH among the oligomers C [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] . The first example shown in more detail is from the extract of a LDPE granulate (Fig.…”

Injector‐internal thermal desorption from edible oils. Part 1: Visual experiments on sample deposition on the liner wall

“…Using visual observation, Bieri et al [14] investigated the performance of the goose neck liner in splitless injection with a fast autosampler. Most recently, the retention of sample liquid in the vaporizing chamber was optimized for large volume splitless injection by the concurrent solvent recondensation (CSR) technique [15].…”

Parametric evaluation for programmable temperature vaporisation large volume injection in gas chromatographic determination of polybrominated diphenyl ethers

“…To lower the limits of the instrumental detectability, large volume injection techniques have been developed. Large volume splitless injection with concurrent solvent recondensation (CSR) allows up to 50 μL sample introduction with the control of sample evaporation in the injector and recondensation in the precolumn [4,5,6,7]. Cool on-column large volume injection uses solvent vapor exit (SVE) behind the precolumn to discharge the solvent vapor before sample transfer to the column.…”