Waters ACQUITY UPC2 BEH, HSS, and CSH Columns - Manual (Page 4)

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[ CARE AND USE MANUAL ]
ACQUITY UPC 2 Torus Columns Care & Use
III. COLUMN USE
To ensure the continued high performance of ACQUITY UPC 2
Columns, follow these guidelines:
a. Sample Preparation
1. Sample impurities often contribute to column contamination.
Waters offers both solid-phase extraction (SPE) and
supercritical fluid extraction (SFE) options. For SPE, use Oasis
®
Solid-Phase Extraction Cartridges/Columns or Sep-Pak ®
Cartridges of the appropriate chemistry to cleanup the sample
before analysis. For more information, visit to
www.waters.
com/sampleprep . Alternatively, Waters offers the MV-10 ASFE
Supercritical Fluid Extraction System for high throughput
extractions from a wide variety of sample matrices.
2. Consider preparing the sample in a weak solvent (such as
heptane) for the best peak shape and sensitivity. Using weak
sample diluents may avoid peak distortion due to “strong
solvent effects” In particular, stronger solvents can impact
peak shapes of low retaining analytes.
3. If the sample is not dissolved in the mobile-phase modifier,
ensure that the sample, solvent and mobile phases are miscible
in order to avoid sample precipitation. Filter sample with
0.2 μm membranes to remove particulates. If the sample is
dissolved in a solvent, ensure that the membrane material
does not dissolve in the solvent. Contact the membrane
manufacturer with solvent compatibility questions. Acrodisc
®
filters are recommended (refer to the Waters Quality
Parts,
® Chromatography Columns and Supplies Catalog for
additional information). Please consider that some analytes
can be retained on certain membrane materials and result
in lower recovery (or lower detector signal) than expected.
Alternatively, centrifugation for 20 minutes at 8000 rpm,
followed by the transfer of the supernatant liquid to an
appropriate vial could be considered.
b. Solvents
To maintain maximum column performance, use high quality
chromatography grade solvents. Solvents containing suspended
particulate materials will generally clog the outside surface
of the inlet distribution frit of the column. This will result in
higher operating pressure, reduced column lifetime, and
compromised performance.
c. Pressure
ACQUITY UPC 2 Column hardware and packing materials can
tolerate pressures of up to 18,000 psi (1241 bar or 124 Mpa).
Pressures greater than 5000 – 6000 psi should be avoided in
order to maximize column and ACQUITY UPC
2 System lifetimes.
d. Useable Flow-Rate Ranges and Expected ACQUITY UPC 2
System Pressures
Table 3 estimates maximum flow rate and system pressure which
can be achieved without over-pressuring the ACQUITY UPC
2
System. The ACQUITY UPC 2 System has a maximum flow rate of
4 mL/minute and maximum pressure of 6000 psi (~400 Bar).
The predicted flow rates and expected backpressure information
is based on the ACQUITY UPC
2 System BPR (Backpressure
Regulator) set at 1800 psi (~120 Bar).
e. Band Spreading Minimization
The ACQUITY UPC 2 System has been designed to minimize band
spreading. Deviation from Waters specified tubing could result
in deterioration of chromatographic performance due to band
spreading induced by inappropriate tubing i.d. Figure 2 shows the
influence of tubing internal diameter on system band spreading
and peak shape. As can be seen, the larger tubing diameter causes
excessive peak broadening and lower sensitivity.
Figure 2: Effect of connecting tubing on system.
Diluted/Distorted Sample Band
0.005 inches
0.020 inches
0.040 inches