ADV06-15_1-412

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2007 vol. 2

Pharmaceutical

More Small

Particles

For more information on the theory

behind small particles, please refer to

the complete article, “Explaining the

Small Particle Advantage,” at

www.restek.com/pharmaceutical

The stated particle size of an HPLC column is actually the mean of the dis-

tribution of all particles used in manufacturing the column. In practice, the

smaller the particle size distribution, the more uniformly packed the column

will be, resulting in higher efficiencies. This distribution is even more critical

when manufacturing columns with particle sizes less than 2μm. If the distri-

bution contains many larger particles and is not tightly controlled, the efficiency

of the column and column-to-column reproducibility will suffer. More impor-

tantly, if the column contains particles less than 1μm (termed “fines”), clog-

ging of the column frit and excessively high column backpressure can result.

1.9μm Pinnacle™ DB columns have a narrow, symmetric particle size distribu-

tion; they contain no particles less than 1μm in diameter. Figure 3 illustrates

this exceptional distribution, which is tighter and more accurate than com-

petitive sub-2μm columns.

1.9μm Pinnacle™ DB columns offer practical advantages for today’s chemist

across a wide range of analytes, from acidic to basic. For higher sample

throughput, matched with the reliability and ruggedness of a column made

entirely by chromatographers for chromatographers, reach for Restek small

particle HPLC columns.

Figure 3

Pinnacle™ DB silica particle size distribution shows an

exceptionally tight, symmetrical distribution around 1.9μm.

Column

Target Particle

Size (μm)

Actual Mean

Particle Size (μm)

Standard

Deviation

Particles

present <1μm

1.9μm Pinnacle

™

1.9

1.952

0.437

Competitor A

1.7

1.993

0.529

Competitor B

1.8

1.832

0.468

Yes

1.9μm Pinnacle™ DB C18 HPLC Columns

Physical Characteristics:

1.9μm Column, 2.1mm

cat. #

price

30mm

9414232

$440

50mm

9414252

$460

100mm

9414212

$520

particle size: 1.9μm

pore size: 140Å

carbon load: 11%

endcap: yes

pH range: 2.5 - 10

temperature limit: 80°C

Catch

the

Buzz!

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No <1μm particles

means better control over

column backpressure.