Waters IC-Pak Ion Exclusion Columns - Manual (Page 3)

[ Care and Use ManUal ]
3 Waters IC-PAK ™ Ion Exclusion Columns
III. PreParatIon oF eluents an saMPles
a. Preparing the Eluent
Follow these guidelines when preparing eluents:
 Recommended eluents are dilute aqueous solutions of acids.
Note: The high concentrations (more than 20%) of organic sol-
vents in the mobile phase will impair column performance. Also
avoid amines, metals, and corrosives such as hydrochloric acid
(HCI).
 Filter eluents to remove microparticulate matter using a
filter of 0.45 µm porosity, or smaller. Use ultrapure water
(18 megohm resistivity), such as that supplied by the Milli-Q
®
reagent grade water system.
 Use vacuum filtration and/or sonication to remove dissolved
gases which could affect your pump.
 Use a Waters in-line precolumn filter to capture any particulates
that may have entered the system.
b. Sample Preparation and Filtration
If the sample contains dissolved contaminants or particulates that
may bind irreversibly to the column, follow one of these procedures:
 Use a Waters Sample Clarification Kit, to filter samples and
prevent the high back pressures that result from blocked column
inlets.
 Use Sep-Pak ® cartridges to remove contaminants from the
sample that may adsorb on the packing material surface, caus-
ing changes in chromatographic performance and reduced
column lifetime.
 Use a Waters Guard-Pak ™ holder, along with IC-Pak Ion Exclusion
Guard-Pak inserts, to adsorb both chemical and physical
contaminants.
IV. oPeratIon
a. Chromatorgraphy guidelines
Liquid chromatography columns have a finite lifetime which ss
directly related to the care and use they receive. Column life is
reduced by contamination from samples and eluents, frequent
eluent changeover and improper handling and storage.
Adopting some of the simple procedures outlined in this and the
previous section can extend column lifetime.
If you observe a change in peak shape, retention of a particular com-
pound, or resolution between two compounds, take immediate steps
to determine the reason. Until the cause of the change is determined,
do not rely upon the results of the analyses.
Note: Before running the first analysis on your new column, perform
the test sample separation given in Section IV. b.
Guidelines
The following operating guidelines will help you obtain the best
performance from the Waters analytical HPLC column:
 Do not exceed an operating pressure of 13 MPa (130 atm or
2,000 psi).
 Filter all eluents. Never use turbid or cloudy mobile phases.
 Protect the column from vibration, mechanical shock, and rapid
changes in pressure, which can result from rapidly changing the
composition of the eluent.
 When using water as a mobile phase component, use water
which has been purified with a Milli-Q water system capable
of delivering 18 megohm water. Neither deionized water nor
bottled HPLC-grade water are acceptable, because they contain
organic compounds which may after column selectivity.
b. Efficiency Testing
Waters columns are tested for adherence to our specifications using
the sample, mobile phase, and flow rate detailed in Table 1. Slight
variations in your results will occur depending on:
 Condition of the equipment used
 Test sample makeup
 Equipment settings and conditions (such as flow rate or composition).