Chromolith^® RP-18e HighResolution HPLC Columns

• Higher Efficiency
• Easy Method Transfer
• Features and Benefits
• Different Lengths to Suit Your Applications
• Specifications
• Application Examples

If you need to combine the high flowrates, little matrix sensitivity, low back pressure, and long lifetime of Chromolith® HPLC columns with even higher efficiency, you need Chromolith® HighResolution. Chromolith® HighResolution RP-18 endcapped HPLC columns are perfect for fast, robust and highly efficient separation of hydrophobic to medium polar compounds at low column back pressure. Chromolith® HighResolution RP-18e columns are the ideal alternative to sub 3 µm particulate columns: They generate similar results as columns packed with core-shell particles but at a much lower back-pressure. Moreover, Chromolith® HighResolution columns offer more than 30% longer lifetime compared with particulate columns.

Higher Efficiency

Like all our Chromolith® HPLC columns, Chromolith® HighResolution RP-18e columns consist of a monolithic rod of high-purity silica with a bimodal structure: macropores reducing back pressure, and mesopores creating a very large active surface area. In contrast to standard Chromolith® columns, however, HighResolution columns feature smaller macropores (1.15 μm as opposed to 2 μm). For this reason, Chromolith® HighResolution columns offer at least 50% higher efficiency than standard Chromolith® columns (exceeding 140,000 plates/meter [Anthracene]), as well as improved peak shape with excellent symmetry. Back pressure is higher than with standard Chromolith® columns but still less than half that of any particulate column of the same dimensions.

Easy Method Transfer

Because the chemical basis of Chromolith® HighResolution RP-18e columns is identical to that of high-end particulate silica columns (e.g. Purospher®), chromatographers can easily use standard methods when developing new protocols, and method transfer from particulate columns to monolithic Chromolith® RP-18 columns is simple and seamless. Chromolith® HighResolution RP-18e columns are included in the US Pharmacopoeia in category L1.

Features and Benefits

• High throughput at high flow rates
• Lower matrix sensitivity
• Column performance is comparable to sub 3 µm particle-packed columns and at least 50 % higher than that of standard Chromolith® columns
• Back pressure is only half that of particulate columns or even less
• 30+% longer column lifetime compared to particle-packed columns
• Possibility of flow gradients
• Added column performance by column coupling
• Simple method transfer from particulate columns

Different Lengths to Suit Your Applications

Column efficiency is directly proportional to column length. Moreover, increasing column length increases resolution due to the higher number of theoretical plates per column.

Chromolith® HighResolution RP-18e columns are available with various lengths in order to perfectly match your application requirements. Moreover, two or even more Chromolith® HighResolution columns can be easily coupled thanks to the low back pressure.

Application Examples

Preservatives

Column	Chromolith® HighResolution RP-18e 100-4.6mm
Mobile phase	ACN / 20mM NaH2PO4 – Buffer pH = 4.5
Gradient	t (min)	ACN (%)	Buffer (%)
	0	20	80
	6	40	60
	7	40	60
Flow rate	2ml/ min
Column pressure	64-70 bar
Temperature	ambient
Detection	uv- 230nm
Detector cell	16µl
Injection vol.	2µl
Sample	Ascorbic Acid     140 µg/ml 4-Hydroxy-benzoic acid 150 µg/ml Benzoic acid 150 µg/ml Sorbic acid 160 µg/ml Methyl-4-Hydroxybenzoate 140 µg/ml Ethyl-4-Hydroxybenzoate 150 µg/ml Propyl-4-Hydroxybenzoate 150 µg/ml

Low pH beta-blockers

Column	Chromolith® HighResolution RP-18e 100-4.6mm
Solvents	23% ACN / 77% KH2PO4 Buffer 20mM pH = 2.5
Flow rate	2ml/ min
Column pressure	76 bar
Temperature	ambient
LC system	LaChrom L7000
Detection	uv- 230nm
Detector cell	16µl
Injection vol.	1µl
Sample	Atenolol 100 µg / ml Pindolol 300 µg / ml Metoprolol 155 µg / ml Bisoprolol 100 µg / ml Labetalol 200 µg / ml Propanolol 20 µg / ml Alprenolol 150 µg / ml

Separation of a mixture of 5 drugs

Column	Chromolith® HighResolution RP-18e 100-4.6mm
Mobile phase	ACN + 0.1% TFA / water + 0.1% TFA
Gradient	t [min]	ACN [%]	Water [%]
	0	1	99
	1,8	60	40
	4,5	60	40
Flow rate	2ml/ min
Column pressure	20-31 bar
Temperature	ambient
Detection	uv- 230nm
Detector cell	16µl
Injection vol.	2µl
Sample	Actaminophen 98 µg/ml Quinine 152 µg/ml Salicylic Acid 140 µg/ml µg/ml Diltiazem 81,2 µg/ml Verapamil 98,4 µg/ml

Separation of 11 steroids

Column	Chromolith® HighResolution RP-18e 100-4.6mm
Mobile phase	ACN / water
Gradient	t [min]	ACN [%]	Water [%]
	0	35	65
	2,5	95	5
	4,5	95	5
Flow rate	2ml/ min
Column pressure	29 - 77 bar
Temperature	22°C
LC system:	Dionex UltiMate3000 (analytical)
Detection	uv- 240nm
Detector cell	11µl
Injection vol.	2µl
Sample	Fluoxymesterone 51 µg / ml Boldenone 43 µg / ml Methandrostenolone 8 µg / ml Testosterone 77 µg / ml Methyltestosterone 35 µg / ml Boldenone-Acetate 13 µg / ml Testosterone-Acetate 71 µg / ml Nandrolone-Propionate 71 µg / ml Testosterone-Propionate 14 µg / ml Nandrolone-Phenylpropionate 69 µg / ml Testosterone-Isocaproate 184 µg / ml

Specifications