Speed up separations and save solvents with Merck UHPLC columns
The use of columns with a 2.1 mm inner diameter will reduce solvent consumption by up to 90%. In addition, by using a UHPLC column from Merck, packed with the reversed-phase sorbent Purospher® STAR RP-18 endcapped 2 µm, the separation time can be decreased by a factor of 10.
In typical routine HPLC laboratories, standard columns of 4.6 mm internal diameter (I.D.) are still used for most applications. On average, such laboratories require 60 L of solvent per year. The used solvents are mostly acetonitrile, methanol, isopropanol, hexane, and/or aqueous buffers. As a result, they generate 60 L of mixed organic/aqueous waste each year.
Purospher® STAR RP-18 endcapped UHPLC columns are ideal for ultra-fast applications where resolution, sensitivity, and sample throughput are crucial. They are the first choice for high-throughput screening and quality control analyses, process monitoring, method development, and LC/MS applications. Due to its balanced selectivity, a Purospher® STAR RP-18 endcapped UHPLC column can be used for a broad range of demanding separations with tailing-free chromatograms.
By using a 50-2.1 UHPLC column packed with Purospher® STAR instead of a 150-4.6 column packed with Purospher®, for the separation of alkylphenones, solvent consumption can be reduced by 89%. Additionally, the separation time can be decreased by a factor of 10.
| Separation of alkylphenones | Sample: Alkylphenone standard |
|---|---|
| 1. Acetanilide 2. Acetophenone 3. Propiophenone 4. Butyrophenone 5. Benzophenone 6. Valerophenone 7. Hexanophenone 8. Heptanophenone 9. Octanophenone |
| Purospher® STAR RP-18 endcapped (5 µm), 150-4.6 mm | |||
|---|---|---|---|
| Column | Purospher® STAR RP-18 endcapped (5 µm), 150-4.6 mm | ![]() |
|
| Eluent | A: water B: acetonitrile |
||
| Gradient |
0.0 min |
45% B 45 - 95% B 45% B |
|
| Flow rate | 1.0 mL/min | ||
| Pressure | 105 bar | ||
| Detection | 247 nm | ||
| Temperature | 40°C | ||
| Inj. volume | 10 µL | ||
| Total run time | 20 min | ||
| Solvent consumption per separation | 20 mL | ||
| Purospher® STAR RP-18 endcapped (2 µm), 50-2.1 mm | |||
|---|---|---|---|
| Column | Purospher® STAR RP-18 endcapped (2 µm), 50-2.1 mm | ![]() |
|
| Eluent | A: water B: acetonitrile |
||
| Gradient |
0.0 min |
55% B 55 - 100% B 55% B |
|
| Flow rate | 1.1 mL/min | ||
| Pressure | 505 bar | ||
| Detection | 247 nm | ||
| Temperature | 40°C | ||
| Inj. volume | 1 µL | ||
| Total run time | 20 min | ||
| Solvent consumption per separation | 2.2 mL | ||
Purospher® STAR UHPLC columns are available in different dimensions, packed with 2 µm or 3 µm particles. The Purospher® STAR RP-18 endcapped 3 µm columns are recommended for difficult samples where clogging and high backpressure is an issue.






