Ultisil XB Series HPLC Columns are based on ultra-pure ( purity > 99.999% ) spherical and totally porous silica, unique bonding chemistry and proprietary surface modification techniques, producing excellent peak shape, column efficiency and exceptional lot-to-lot reproducibility. Ultisil column is the best choice for method development, owing to complete bonding chemistries and stable performance.
Features
- Ultra-pure spherical porous silica, purity > 99.999%
- Wide pH range: 1.5-10
- High efficiency: theoretical plate > 80000/m
- Excellent peak symmetry: tailing factor=0.95~1.05
- Exceptional lot-to-lot reproducibility


Column Parameters
Columns | USP | pH range | Carbon Loading(%) | Surface Area(m2/g) | Endcapped | Max. Temp.(°C) |
Ultisil XB-C18 | L1 | 1.5-10.0 | 17(120Å), 8(300Å) | 320(120Å), 90(300Å) | Yes | 60(pH≤6.5), 40(pH>6.5) |
Ultisil XB-C8 | L7 | 1.5-10.0 | 12%(120Å), 4%(300Å) | 320(120Å), 90(300Å) | Yes | 60(pH≤6.5), 40(pH>6.5) |
Ultisil XB-Phenyl | L11 | 1.5-10.0 | 12%(120Å), 4%(300Å) | 320(120Å), 90(300Å) | Yes | 60(pH≤6.5), 40(pH>6.5) |
Ultisil XB-C4 | L26 | 1.5-10.0 | 8%(120Å), 3%(300Å) | 320(120Å), 90(300Å) | Yes | 60(pH≤6.5), 40(pH>6.5) |
Ultisil XB-C1 | L13 | 1.5-10.0 | 4%(120Å) | 320(120Å) | Yes | 60(pH≤6.5), 40(pH>6.5) |
Ultisil XB-CN | L10 | 1.5-9.0 | 7%(120Å) | 320(120Å) | Yes | 60(pH≤6.5), 40(pH>6.5) |
FeaturesTrace Amount Metal Contents Test
A useful chromatographic test of trace amount of metal contents in the column is to compare the peak symmetry of one pair of positional isomers, 4,4’-dipyridyl and 2,2’-dipyridyl, and a neutral chelating reagent, 1,2-dihydroxylnaphthalene. 4,4’-dipyridyl, which cannot form chelating complex with metal, is used as a reference. 2,2’-dipyridyl and 1,2-dihydroxylnaphthalene, which are chelating reagents, are sensitive to trace amount metal in silica. When a C18 column based on type A silica or other so-called type B silica with higher metal content is used, the peaks of 2,2’-dipyridyl and 1,2-dihydroxylnaphthalene would tail or even totally disappear.

Column | Ultisil XB-C18, 4.6×150mm, 5μm |
Mobile Phase: | 20 mM phosphate(pH 7.6) / methanol=55/45 |
Flow rate | 1.0mL/min |
Detector | 215nm |
Temperature | 25°C |
Injection Volume | 1μL |
Samples | 1) 4,4’-Dipyridyl 2) 2,2’-Dipyridyl 3) 1,2-Dihydroxylnaphthalene |
Separation of Basic Compounds Antidepressant at pH 7.0

Column | Ultisil XB-C18, 4.6×150 mm, 5μm |
Mobile Phase: | 20 mM phosphate(pH 7.0) / methanol=20/80 |
Flow rate | 1.0 mL/min |
Detector | 215 nm |
Temp. | 25°C |
Samples | 1) Uracil 2) Ropranolol 3) Ortriptyline 4) Amitryptyline 5) Trimipramine |
Comparison of Peak Shape between Batch to Batch

Column | Ultisil XB-C18, 4.6×250 mm, 5μm |
Mobile Phase: | Methanol/water=75/25 |
Flow rate | 1.0mL/min |
Detector | 254nm |
Temp. | 25°C |
Samples | 1) Uracil 2)Phenol 3) 4-chloronitrobenzen 4) Methylbenzene |
Capacity Factor(K’) of Batch to Batch Reproducibility

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About us
Welch Materials is a multinational company that develops and manufactures chromatography consumables including HPLC column, Solid Phase Extraction (SPE) column, GC column, Prep column, Flash column and packing materials.
Our initial strength was our extensive experience on particle surface modification science and techniques. We are experts on bonding
chemistry and innovative packing materials for chromatography applications. Through the optimal utilization of our resources, we have developed many innovative LC and GC consumable products, in particular, our six series HPLC columns, Ultisil®, Welchrom®, Xtimate®, Topsil®, Boltimate® and Blossmate®.
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