September 24, 2011

A Quick Study ‐ Comparison of Chromatography
Normal Phase vs. Flash on the Gilson PLC 2020
Application NoteKeywords
Purification, Normal Phase Chromatography, Flash Chromatography, PLC 2020,
Preparative Chromatography

Introduction
This study was performed by Matthew Smith with Gilson UK in the United Kingdom.
This application note provides a quick comparison of three pharmaceuticalcompounds using high pressure normal phase and low pressure flash
chromatography on the Gilson PLC 2020 Personal Purification System. Comparisonof peak shape, peak retention time, chromatography run time, fraction volume, andsolvent consumption were all studied to determine the most efficient and optimal
chromatography method.
The touch screen control on the PLC 2020 allows for
simple and quick modifications to method gradients.
The built‐in solvent selection valve offers efficientmobile phase choices to be made for faster compound
elution and/or increased compound resolution duringsemi‐preparative and preparative chromatography
runs. Additional studies on the comparison of highpressure normal phase and low pressure flash
chromatography will provide further details on
purification percent recovery, peak width, and peakresolution.

Figure 1. Gilson PLC 2020 Personal Purification System

Gilson, Inc. World Headquarters
Middleton, WI 53562 USA
Telephone: 800‐445‐7661

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September 24, 2011Materials & Methods
Materials & Methods for the PLC 2020 System
All solvents used were HPLC grade or higher. All reagents were ACS grade or better.
Compounds: ~ 100 mg each in Hexane
Benzocaine – anesthetic compound
Caffeine – natural
Dipyridamole – cardiovascular drug
General Conditions:
Injection:
Flow Rate:

1 mL
25 mL/min

Normal Phase Preparative System:
Injection (mL): 1Column:
Macherey‐Nagel; NUCLEODUR® VarioPrep 21 x 50 mm; 5 µFlash Preparative System:
Injection (mL): 1Column:
Macherey‐Nagel; CHROMABOND® 25g SiOH; 21.2 x 16.5 mm

Results & Summary
Table 1. Summary ‐ Normal Phase (NP) vs. Flash Chromatography Injections on theGilson PLC 2020

Peak Name

NP/Flash
Peak
Retention
Time (min)NP/Flash
Fraction
Collection
Volume (mL)

Caffeine

4.8/7.3

15/40

Benzocaine

2.9/4.5

11/19

Dipyridamole

0.7/1.4

7/11

Gilson, Inc. World Headquarters
Middleton, WI 53562 USA
Telephone: 800‐445‐7661

NP/Flash
Total Run
Time (min)NP/Flash
Total Solvent
Consumption
per Injection
(mL)

6/10

150/250

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September 24, 2011

Figure 2. High Pressure Normal Phase Chromatography Injection on the Gilson PLC 2020

Figure 3. Low Pressure Flash Chromatography Injection on the Gilson PLC 2020

Gilson, Inc. World Headquarters
Middleton, WI 53562 USA
Telephone: 800‐445‐7661

Page |3

September 24, 2011

Visual comparison of peak shape immediate shows a comparison of compound peak
response. Peak height values for each of the three compounds injected on thenormal phase column are almost double the peak height values for the same
compounds injected on the flash column. Flash chromatography shows much wider
peaks, with the caffeine peak requiring three fraction tubes to collect the full peak in
40 mL versus a single fraction tube to collect the same compound from the normal
phase chromatography injection.
Run time using a high pressure, normal phase column is reduced by 40% over using
a low pressure flash column, and this directly correlates to savings in mobile phaserequired per injection. The amount of mobile phase used per injection depends onthe flow rate used, and in this quick study, one liter of mobile phase solvent would
be saved for every ten injections made if the normal phase column were usedinstead of the flash column.
Future studies will provide additional supporting information for this quick study
that clearly shows the benefits of using high pressure normal phase instead of low
pressure flash chromatography for peak shape, peak retention time,
chromatography run time, fraction volume, and solvent consumption.

Gilson, Inc. World Headquarters
Middleton, WI 53562 USA
Telephone: 800‐445‐7661

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