IDEX Sample Loops

Idex Sample Loops

IDEX sample loops deliver accurate, repeatable sample injection for liquid chromatography and analytical fluid-handling systems. Available in both stainless steel and PEEK, these precision-formed loops support reliable volume delivery for standards and unknowns, making them ideal for routine LC, UHPLC, and diagnostic workflows.

Stainless steel sample loops feature burr-free, square-cut ends that ensure flush connections to valve ports for consistent sealing and minimal dead volume. Loop size designations are nominal, as most analyses use the same loop for both standards and samples. These loops are supplied with unswaged fittings and must be fully seated in the injector port before ferrules are swaged in place to achieve proper installation.

PEEK sample loops provide a flexible, metal-free alternative with excellent chemical resistance and biocompatibility. Clean, straight-cut ends allow easy valve installation, while the inert PEEK polymer withstands exposure to nearly all organic solvents. PEEK loops are also supplied with unswaged fittings but allow repositioning along the tubing during installation, simplifying setup and ensuring correct loop placement.

Chrom Tech offers a broad selection of IDEX stainless steel and PEEK sample loops in common volumes and tubing configurations. With many popular sizes in stock and ready to ship, we make it easy to select the right loop for dependable sample injection and consistent chromatographic performance.

Stainless Steel Sample Loops

PART NO VOLUME BORE ID TUBING OD
 
RHEODYNE STAINLESS STEEL LOOPS FOR 7125, 7010 INJECTION VALVES (DO NOT USE FOR 7725)
70205 µL0.18 mm (0.007")1/16"
702110 µL0.30 mm (0.012")1/16"
702220 µL0.51 mm (0.021")1/16"
702350 µL0.51 mm (0.021")1/16"
7024100 µL0.51 mm (0.021")1/16"
7026500 µL0.76 mm (0.030")1/16"
70271.0 mL0.76 mm (0.030")1/16"
70282.0 mL1.0 mm (0.040")1/16"
70295.0 mL1.0 mm (0.040")1/16"
187610 mL2.0 mm (0.080")1/8"
RHEODYNE STAINLESS STEEL LOOPS FOR 3725-038, 3725I-038 INJ VALVES
3065-0182.0 mL2.0 mm (0.080")1/8"
3065-0195.0 mL2.0 mm (0.080")1/8"
3065-02310 mL2.0 mm (0.080")1/8"
3065-02520 mL2.0 mm (0.080")1/8"
RHEODYNE STAINLESS STEEL LOOPS FOR 7725, 7725I, PR/EV700-1000, PR/EV703-100, MX MODULE INJECTION VALVES (DO NOT USE FOR 7125)
7755-0205 µL0.18 mm (0.007")1/16"
7755-02110 µL0.30 mm (0.012")1/16"
7755-02220 µL0.30 mm (0.012")1/16"
7755-02350 µL0.51 mm (0.021")1/16"
7755-024100 µL0.51 mm (0.021")1/16"
7755-025200 µL0.76 mm (0.030")1/16"
7755-026500 µL0.76 mm (0.030")1/16"
7755-0271.0 mL0.76 mm (0.030")1/16"
7755-0282.0 mL1.0 mm (0.040")1/16"
7755-0295.0 mL1.0 mm (0.040")1/16"
187610 mL2.0 mm (0.080")1/8"
RHEODYNE STAINLESS STEEL LOOPS FOR 8125 INJECTOR (USE 7755-024 TO 7755-029 FOR VOLUMES > 50 µL)
802110 µL0.20 mm (0.008")0.020"

Peek Sample Loops

PART NO VOLUME BORE ID TUBING OD
 
PEEK LOOPS FOR 3725, 3725I INJECTION VALVES
3055-0182.0 mL1.6 mm (0.062")1/8"
3055-0195.0 mL1.6 mm (0.062")1/8"
3055-02310 mL2.0 mm (0.080")1/8"
3055-02520 mL2.0 mm (0.080")1/8"
PEEK LOOPS FOR 9725, 9010, PR/EV750-100, PR/EV753-100 INJ VALVES
18002 µL0.13 mm (0.005")1/16"
9055-0205.0 µL0.18 mm (0.007")1/16"
9055-02110 µL0.25 mm (0.010")1/16"
9055-02220 µL0.25 mm (0.010")1/16"
9055-02350 µL0.51 mm (0.021")1/16"
9055-024100 µL0.51 mm (0.021")1/16"
9055-025200 µL0.51 mm (0.021")1/16"
9055-026500 µL0.76 mm (0.030")1/16"
9055-0271.0 mL0.76 mm (0.030")1/16"
9055-0282.0 mL0.76 mm (0.030")1/16"
9055-0295.0 mL0.76 mm (0.030")1/16"
PEEK LOOPS FOR 7725, 7725I, PR/EV700-100
7123-2271 µLInternal groove (models PR/EV700-100, EV750-100 only) 
7755-0152 µLInternal groove (models 7725, 7725i, and 9725(i) only) 
Key Definitions â–¸
Sample Loop
A fixed-length section of tubing used in injection valves to define and deliver a precise volume of sample into a chromatographic flow path during manual or automated injection.
Nominal Loop Volume
The labeled volume of a sample loop based on tubing dimensions and length. Actual delivered volume may vary slightly, but consistency is maintained when the same loop is used for both standards and samples.
Unswaged Fittings
Compression fittings supplied loose on sample loop tubing, allowing proper positioning in valve ports before ferrules are permanently seated or swaged into place.
Biocompatible PEEK
A high-performance polymer material that is inert to most organic solvents and suitable for biological applications, commonly used in metal-free fluidic components such as PEEK sample loops.
Flush-Cut Tubing Ends
Precisely machined tubing terminations that sit flat against valve ports to minimize dead volume and ensure consistent sealing in stainless steel and polymer sample loops.
Frequently Asked Questions â–¸
What is a sample loop used for in HPLC?
A sample loop defines the injection volume by holding a fixed amount of sample before it is introduced into the chromatographic flow path. It ensures consistent sample delivery for both standards and unknowns.
Do I need to know the exact loop volume?
In most workflows, exact volume is not critical because both standards and samples are analyzed using the same loop. Loop size designations are nominal, providing reliable injection-to-injection repeatability.
What is the difference between stainless steel and PEEK sample loops?
Stainless steel loops provide rigid, high-pressure performance with flush-cut ends for minimal dead volume, while PEEK loops offer a flexible, metal-free alternative with excellent chemical resistance and biocompatibility for sensitive applications.
How do I properly install a stainless steel sample loop?
Stainless steel loops must be fully bottomed into the injector port before swaging the ferrules onto the tubing. This ensures a flush connection and prevents leaks or dead volume at the valve interface.
Are PEEK sample loops easier to install?
Yes. PEEK loops allow fittings to reposition along the tubing during installation, making setup more forgiving while still providing reliable sealing in valve ports.