Leaks in gas chromatography can be extremely frustrating and time consuming to identify and rectify. Preventing leaks by employing best practices is a preferred strategy in all cases. Unfortunately, the vast majority of chromatographers have been taught incorrect techniques for cutting columns and for making quick connections in press fit type connectors.

Column trimming is not a art: it is a science called Fracture Mechanics. The number one practitioners of this science -- by orders of magnitude -- are telecom fiber optics installers and each and every one of them would be appalled to see how chromatographers have been told to cut capillary. There are those who claim that capillary is somehow different from fiber so the fiber cutting techniques don't work: BALDERDASH. This deck shows how capillary columns should be cut.

Even knowing how to cut columns is not always enough. Where Telco has semi-automatic and automatic tools for "cleaving" fiber, there is no such tool for the larger diameters of GC columns. Chromatographers have to learn to do it by hand. Accordingly, all column cuts will not be prefect so, when using a press fit, it is essential to select the one that is designed to seal on far less than perfect cuts.

Press fit connectors have a bad reputation throughout the GCverse, and it is a very well deserved reputation for the most part because manufacture of the devices that actually work, first time and every time, was halted a decade ago and cheap copies rapidly filled the void. The original is now back and better in every way, forming gas-tight seals on appallingly ragged column ends (does that sound like yours?).

Leaks in gas chromatography can be extremely frustrating and time consuming to identify and rectify. Preventing leaks by employing best practices is a preferred strategy in all cases. Unfortunately, the vast majority of chromatographers have been taught incorrect techniques for cutting columns and for making quick connections in press fit type connectors.

Column trimming is not a art: it is a science called Fracture Mechanics. The number one practitioners of this science -- by orders of magnitude -- are telecom fiber optics installers and each and every one of them would be appalled to see how chromatographers have been told to cut capillary. There are those who claim that capillary is somehow different from fiber so the fiber cutting techniques don't work: BALDERDASH. This deck shows how capillary columns should be cut.

Even knowing how to cut columns is not always enough. Where Telco has semi-automatic and automatic tools for "cleaving" fiber, there is no such tool for the larger diameters of GC columns. Chromatographers have to learn to do it by hand. Accordingly, all column cuts will not be prefect so, when using a press fit, it is essential to select the one that is designed to seal on far less than perfect cuts.

Press fit connectors have a bad reputation throughout the GCverse, and it is a very well deserved reputation for the most part because manufacture of the devices that actually work, first time and every time, was halted a decade ago and cheap copies rapidly filled the void. The original is now back and better in every way, forming gas-tight seals on appallingly ragged column ends (does that sound like yours?).

The Pulsar™ HPC begins inside the surgical laser itself, acting as an extension of the optics train rather than an accessory. InnovaQuartz recognized that the laser’s focal lens could be used as half of a Galilean beam expander if a second, concave lens could be provided by the optical fiber. The input face of the Pulsar HPC is laser-formed concave, with a convex rim about the concavity; we call this a compound annular lens system. The concave center collimates the foal energy like a Galilean beam expander (in reverse) while the convex annulus discriminates between the stable laser output and the unstable, rejecting the latter.

Other features within the termination strip off the rejected energy for dissipation so this potentially destructive energy never enters the fiber. The result is safe transit for energy capable of doing surgical work without bearing the load of highly divergent energy that has no surgical utility.

The ProFlex™ LLF fiber features Smooth Passage™ tips that do not gouge or hang-up in the ureteroscope working channel and do not snap-off.

The ProFlex LLF is available for most holmium lasers that have been cleared for surgical use, including the hard to find, small core fibers for the DEKA Smart 2100 laser and Trimedyne OmniPulse. Sizes available are 150, 200, 273, 365, 550 and 910 microns and most models are available as single use or reusable devices. (See our slide presentation on real fiber sizes – currently in draft but coming soon.)