HP 7680T Supercritical Fluid Extractor (SFE)

The HP 7680T Supercritical Fluid Extractor (SFE) was first introduced in 1992. An extension of the HP 7680A, its design includes the addition of a sample turret (hence the “T” designation) to increase its load to eight sample vessels or ‘thimbles’, each having a sample capacity of up to 7mL. The maximum pressure and temperature at which extractions can be performed is 386 atm and 150°C, respectively. In use, the loaded stainless-steel thimbles are sealed with finger-tight end caps containing integral porous stainless-steel frits. These are placed in the turret, which rotates to the appropriate position. A piston or ram rises up from underneath the turret and conveys the sample thimble into the oven where the extraction begins. Analytes are collected on a solid phase trap which is automatically washed by a solvent (or solvents) into GC-type autosampler vials mounted on a carousel.

The entire system is controlled by computer. The system is able to run a maximum of eight samples which, given a typical extraction time of 30-45 min, cannot be used during overnight operations. This situation was indirectly addressed by the later addition of the ‘bridge’, which allowed the HP 7680T to be interfaced with a GC or HPLC system via an autosampler. Here the autosampler arm acts as a bridge to transfer vials from the SFE rack to the autosampler rack on the chromatograph. This provided an additional level of analytical automation but did not improve the SFE throughput since only eight samplers could be extracted before operator intervention. The pumping system is a dual-piston reciprocating pump derived from the HP 1080 HPLC. With all things considered, the HP 7680T was the first system that could realistically be considered automated.

This system was in working condition at the time of its retirement. Sold as-is with no additional testing or warranty. 7 days right of return.