HAIGUARD

Higgins Analytical provides chromatographers with a new concept in HPLC guard column technology. For the first time, users can protect their analytical HPLC column's from both chemical and particulate contamination with a device that does not interfere with the analytical column's chromatographic process. The ability to periodically inspect the device for contamination is a further example of this product's uniqueness.

Leak Free:  The HAIGUARD Holder's novel seal design assures leak-free operation. The Holder has undergone destructive testing at more than 10,000 PSI -- higher pressure than most instruments can even generate. While we don't recommend doing chromatography under conditions that would result in such high pressures, it is comforting to know that none of the HAIGUARD Holders tested experienced a leak.

No Tools Required:  One of the first things you will notice is that there is no knurling or wrench flat on the HAIGUARD Holder. Holder installation and Guard-Disc changes are accomplished without any tools. And, the reliable, leak-free performance, even under the challenging operating conditions used on some of today's modern HPLC columns, is achieved with only the slightest finger-tight torque during holder assembly. There is no more need to tear apart the lab looking for the ¼" wrench that's never where you left it.

Inert Construction:  The Holder is machined from a high density PEEK extrusion. This provides not only a rugged design, but it also assures chemical inertness to commonly used HPLC solvents and buffer systems. This is especially important in applications where biocompatibility is a concern or electrochemical detection is involved. The HAIGUARD Holder and Guard-Disc System is the perfect complement to your biocompatible HPLC system and PEEK HPLC columns. Another advantage is that the PEEK threads will never gall or corrode as they do on many manufacturers' guard holder designs.

Visual Contamination Checks:  One of the biggest issues with guard column use is the uncertainty about when it should be changed. A recently published survey indicated that the typical user changes a guard column very few times throughout the analytical column's lifetime. One reason for this poor practice is that, except for back pressure build up, most indications of guard column failure come long after the analytical column has been damaged. With a Guard-Disc, a more rational approach can be taken. The Guard-Disc's unique design makes it the only HPLC column guard system that is capable of being visually inspected on a periodic basis. The Holder can be quickly opened to inspect the top surface of the disc for contamination, particles, or discoloration.

Compatibility:  The HAIGUARD Holder is supplied with a tube-stop depth compatible with fittings found on most manufacturers' HPLC columns. If, however, you use columns with a different tube-stop depth, it is a simple matter to replace the 1/16" PEEK tube with a different length piece. So, with a new HAIGUARD Holder, you'll no longer need that box full of bent-up plumbing you've assembled for different types of HPLC columns.

High Performance:  The small volumes and the direct connection to the HPLC column means that the performance loss due to the Guard-Disc and HAIGUARD Holder is minimal. Most applications and systems will be unable to detect a difference in a separation when a Guard-Disc is connected to an an alytical column. More importantly, you can be sure that the selectivity of the analytical column is not going to be altered by Guard-Disc selectivity. Guard-Discs are offered with four popular chemistries addressing the majority of your chromatographic needs.

Special Applications:

The unique design of the HAIGUARD System allows it to be connected directly to your instrument's sample injection valve. This configuration is ideal for not only routine HPLC system protection, but it especially effective for narrow bore or microbore applications where any system band broadening is highly undesirable.

Off-Line Sample Purification:  By placing a HAIGUARD System between the HPLC pump or gradient mixer and the sample injection valve as pictured below you can be certain that no pump seal fragments or particles from the mobile phase will enter the sample injection valve and clog its small passages, scratch the rotor and stator, and plug up the small surface on top of the micro column.

Bidirectional Flow Option for HAIGUARD:  Another example of the HAIGUARD System's flexibility is its ability to perform off-line sample purifications. The 1/16" PEEK through tube can be exchanged for a longer piece which serves as a cannula aiding sample transfer. An optional luer adapter (P/N GD-LUER) is available, facilitating the connection of a syringe to the Holder. This convenient modification permits off-line manual sample preparation methods. Aqueous and organic solutions can be passed from the syringe through the Guard-Disc at a rate of 4 - 5 mL/min with moderate hand pressure. The HAIGUARD System's small internal volume allows you to work with very small volumes and experience negligible sample dilution and losses. This technique has been proven to be an effective and cost effective way of removing protein material from a sample matrix.

Standard HAIGUARD holders are designed for use with solvent flow in a single direction. Applications requiring flow in both directions should use the Bidirectional HAIGUARD Holder (P/N GD-BKIT). Standard HAIGUARD Holders can become Bidirectional Holders by replacing the female end with the optional Bidirectional Female End (P/N GD-BOPT) illustrated below.

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© 1996, 1997, 1998 Higgins Analytical, Inc (Version Date: 8Aug98)
REV 4/29/00