APPLICATION NOTE

AN080397-03

Comparison of STYROS™ 1R/XP and 1R/XH.

The STYROS™ chromatographic stationary phase family of products has been developed to permit a seamless transition from analytical to preparative scale.

In the past, researchers had to make several compromises concerning pressure drop and efficiency.

Small particle sizes were used for analytical separations, in order to maximize the theoretical plates. This resulted in considerable back pressure.

Due to the hardware limitations and cost considerations, large-size particles have been used in micro preparative and preparative scale applications, resulting in low back pressure at the expense of significant loss in theoretical plates as compared with analytical columns.

We have recognized at OraChrom, the need for a chromatographic media that provides both the high performance and the low back pressure at the same time. Due to our carefully optimized polymerization technique, the special particle size distribution and the high pressure tolerance of STYROS™ media, it is now possible to provide packed columns for high performance analytical as well as preparative applications without necessarily sacrificing the efficiency.

The STYROS™ XP series have been developed to provide high resolution separations with minimal back pressure.

The XH series, with over 35,000 plates/m, are intended more as analytical columns for fast separations and optimal back pressure.

The N/DP ratio (N: theoretical plates, DP: pressure drop across the column) is an important factor that has great significance in determining the practicality of an LC column as a component of a large scale preparative process.

	Chromatogram 1. Standard Protein Separation on STYROS™ 1 R/XH at 1 ml/min (360 cm/hr).
	Chromatogram 2. Standard Protein Separation on STYROS™ 1 R/XH at 5 ml/min (1,800 cm/hr).

The chromatographic conditions are gathered in the following table:

Table 1. Operating Parameters For Chromatograms 1-4.

	HPLC System	Hewlett Packard 1050
	Detector	214 nm
	Column	STYROSÔ 1 R/XH 50x4.6mm ( Chromatogram 1 & 2 ) STYROSÔ 2 R/XP 50x4.6 mm ( Chromatogram 3 & 4 )
	Mobile Phase	A: 0.1 % TFA in water B: 0.1 % TFA in Acetonitrile/water (95/5)
	Gradient	15-80% B in 10 ml
	Flow rate	1 and 5 ml/min
	Temperature	Ambient
	Injection volume	10 ml
	Sample: 1 mg/ml each	1: Cytochrome C, 2: Lysozyme 3: b-Lactoglobulin, 4: Ovalbumin

		Chromatogram 3. Standard Protein Separation on STYROS™ 1 R/XP at 1 ml/min (360 cm/hr).
		Chromatogram 4. Standard Protein Separation on STYROS™ 1 R/XP at 5 ml/min (1,800 cm/hr).

Back to List of Application Notes