Chemistry |
C18 |
Separation Mode |
Reversed Phase |
Particle Substrate |
Silica |
pH Range Min |
2 pH |
pH Range Max |
8 pH |
Maximum Pressure |
6000 psi (415 Bar) |
Endcapped |
Yes |
Bonding Technology |
Shield RP18 |
Silanol Activity |
Low |
Particle Shape |
Spherical |
Particle Size |
5 µm |
Endfitting Type |
Waters |
Pore Size |
100 Å |
Format |
Column |
Surface Area |
335 |
System |
HPLC |
USP Classification |
L1 |
Inner Diameter |
4.6 mm |
Length |
250 mm |
Carbon Load |
17 % |
UNSPSC |
41115709 |
Brand |
Symmetry |
Product Type |
Columns |
Units per Package |
1 pk |
Symmetry Shield RP18 Column, 100Å, 5 µm, 4.6 mm X 250 mm, 1/pk
For those seeking significantly improved peak shape and resolution, Water’s Symmetry Shield RP18 Column features patented embedded polar group technology that acts as a “shield” for the silica’s residual silanol surface from highly basic analytes. As a result of this embedded polar group, the activity of surface silanols is reduced, allowing the columns to exhibit lower retention of basic compounds when compared to conventional C8 and C18 columns. This has allowed Symmetry Shield HPLC columns to set the industry standard among lab equipment for performance for peak shape of basic compounds.
Symmetry Shield columns deliver USPW Tailing Factors of less than 1.2 over a pH range between pH 2 and pH 8. With this lower limit of detection and quantitation, chromatographers will be able to develop new methods faster, improving productivity without sacrificing the selectivity. Symmetry Shield columns have been shown to provide much better separations without the need to change mobile phases.
For applications that require low organic, highly aqueous mobile phase conditions, the Shield Technology offered in all Symmetry Shield columns contains reversed-phase and water-wettable particles. These particles allow better interaction between the particles and samples, leading to stable retention in highly aqueous mobile phases along with superior peak shape.
Symmetry columns are designed for high performance for reproducibility, using high purity silica and tightly controlled manufacturing protocols to ensure all columns exceed the standards for HPLC performance. No other silica-based LC column brand offers the same column to column and batch to batch reproducibility. Narrow specification ranges minimize variation, promising the confidence you need. Also consider the Symmetry Shield RP18 VanGuard Cartridge, 100Å, 5 µm, 3.9 mm X 5 mm, 3/pk for maximizing efficiency and positive results in chromatographic applications.
Each Symmetry column includes a Certificate of Analysis and Performance Test Chromatogram, including the gel batch number, analysis of unbonded particles and bonded particles, and chromatographic results and conditions.
What Is A USP Tailing Factor?
The tailing factor is a measure of peak tailing used in chromatography. It is defined by the United States Pharmacopeia. It is defined as the distance from the front slope of the peak to the back slope, divided by twice the distance from the centerline of the leak to the front of the slope. All measurements are made at 5% of the maximum peak height. Typically, the tailing factor will be similar to the asymmetry factor for the same peak, though the values cannot be converted directly.