Chromolith® Prep

Comparison with Particulate Material

The selectivity of Chromolith® Prep RP-18 endcapped monolithic columns is comparable to common RP-18 endcapped reversed phase columns. However, the high speed and high efficiency of these preparative columns make them excellent for separations of non-polar basic and acidic compounds as well as peptides.

In most cases, existing methods using particulate columns can be easily transferred to Chromolith® Prep. However, for some applications, it is worth optimizing the method in order to make use of the full potential of this enhanced technology.

Comparison of Chromolith® Prep RP-18 Endcapped 100-25 mm with Particulate Material: Separation of Oxime Derivates

The comparison of Chromolith® Prep RP-18 endcapped with a particulate Purospher RP-18 endcapped column (250-50 mm) shows that both separations have a similar resolution under the same chromatographic conditions. However, Chromolith® Prep RP-18 endcapped has better selectivity than Purospher RP-18 endcapped, as exhibited by the resolution of the additional isomer peak at 7 minutes.

Packing stand NW 50 (250-50) filled with Purospher RP-18 endcapped, 10 μm

Column	Packing stand NW 50 (250-50) filled with Purospher® RP-18 endcapped, 10 μm
Mobile Phase	A: Water + 0.05% TFA B: Acetonitrile + 0.05% TFA
Gradient	linear in 30 min up to 100% B
Flow rate	100 mL/min
Detection	UV 210 nm
Sample	125 mg oxime derivates in 500 μL Acetonitrile

Chromolith® Prep RP-18 endcapped 100-25 mm

Column	Chromolith® Prep RP-18 endcapped 100-25 mm
Mobile Phase	A: Water + 0.05% TFA B: Acetonitrile + 0.05% TFA
Gradient	linear in 11 min up to 100% B
Flow rate	100 mL/min
Detection	UV 210 nm
Sample	125 mg oxime derivates in 500 μL Acetonitrile

Separation of Hirudin (Filtrate of Crude Extract)

Without any sample preparation, the crude sample was injected directly onto the Chromolith® Prep RP-18 endcapped column. The separation took only 5 minutes, in which the target product was successfully isolated from the impurities.

Chromolith® Prep RP-18 endcapped 100-25 mm

Column	Chromolith® Prep RP-18 endcapped 100-25 mm
Mobile Phase	A: Water + 0.1% Formic acid B: Acetonitrile 100%
Gradient	Time [min]	%A	%B
	0	90	10
	10	70	30
	10.1	90	10
Flow rate	60 mL/min
Detection	UV 254 nm
Sample	23 mg hirudin (filtrate of crude extract) injected in 5 mL solution

Separation of Dihydropyridines (Nifedipine, Nimodipine and Nisoldipine)

With the monolithic silica rod technology of Chromolith® Prep RP-18 endcapped columns, it is possible to speed up separations significantly while reducing back pressure.

Chromolith® Prep RP-18 endcapped 100-25 mm

Column	Chromolith® Prep RP-18 endcapped 100-25 mm
Mobile Phase	A: Water B: Acetonitrile
Gradient	Time [min]	%A	%B
	0	80	20
	8	20	80
	8.1	80	20
Flow rate	10 mL/min
Detection	UV 224 nm
Sample	90 mg mixture of nifedipine, nimodipine and nisoldipine

Chromolith® Prep Product Range