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Chromolith® RP-8 Endcapped Monolithic
Silica HPLC Columns


Chromolith® RP-8 Endcapped HPLC Columns

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Superior Retention for Hydrophobic Compounds

Chromolith® RP-8 Endcapped

Chromolith® RP-8 endcapped columns provide better retention for hydrophobic compounds than RP-18 endcapped columns. Due to their shorter alkyl chains, they offer less retention and slightly different selectivity. This makes it possible to achieve baseline separations
on RP-8 endcapped bonded columns. In comparison, no separation at all is observed on RP-18 endcapped bonded silica columns under identical elution conditions.

Otherwise, Chromolith® RP-8 endcapped columns offer the same outstanding benefits as Chromolith® RP-18 endcapped: high throughput, extremely long column lifetime, lower matrix sensitivity and added column performance through column coupling. Based on high-purity silica, the columns minimize the negative effects of trace metals. Furthermore, they are chemically modified with n-alkyl chains, which possess a high ligand density, and fully endcapped in order to reduce the effects of unmodified silanol groups.

Features and Benefits

  • Better retention for hydrophobic compounds 
  • High throughput at high flow rates with the best overall column quality 
  • Possibility of flow gradients
  • Added column performance by column coupling 
  • Rigid monolithic structure for a longer column lifetime
  • Lower matrix sensitivity


Silica type High-purity
Particle size Monolithic
Macropore size 2 μm
Mesopore size 13 nm (130 Å)
Pore volume 1.0 mL/g
Total porosity > 80%
Surface area 300 m2/g
Surface modification RP-8 endcapped
Carbon content 11%

Applicatgion Example Chromolith® Performance RP-8e

Column Chromolith® Performance RP-8 endcapped, 100-4.6 mm
Mobile phase A: Acetonitrile/ water 90/ 10 + 0.1% TFA
B: 0.1% TFA in water 
Gradient Time/min %A %B
0.0 45 55
1.0 90 10
3.0 90 10
Flow rate 2 mL/min
Pressure 30 -40 bar
Detection 214 nm
Temperature Ambient
Injection volume 30 μl

1. (Sar1, Ala8)-Angiotensin II
2. (Sar1, Ile8)-Angiotensin II
3. Angiotensin

87 μg/mL
87 μg/mL
47 μg/mL

Chromolith® Performance RP-8 endcapped, 100-4.6 mm

Column Chromolith® Performance RP-8 endcapped, 100-4.6 mm
Mobile phase A: Acetonitrile
B: 20mM NaH2PO4 pH 2.5 
Gradient Time/min %A
0.0 2
0.5 18
8.5 18
9.1 32
16 32
Flow rate 1 mL/min
Pressure 23 bar
Detection 220 nm
Temperature Ambient
Injection volume 5 μl

1. Malic acid
2. Succinic acid
3. Glutaric acid
4. 3,4-Dihydroxy-cinnamic acid
5. 4-Hydroxy-cinnamic acid
6. Sorbic acid
7. Benzoic acid
8. 2-Hydroxybenzoic acid
9. Cinnamic acid

0.92 mg/mL
1.70 mg/mL
1.20 mg/mL
0.02 mg/mL
0.03 mg/mL
0.20 mg/mL
0.04 mg/mL
0.15 mg/mL
0.04 mg/mL

Chromolith® Performance RP-8 endcapped, 100-4.6 mm

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