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Maintenance and care
AZURA® Detector DAD 6.1L, DAD 2.1L, MWD 2.1L Instructions, V6700
Check if the baseline noise has disappeared.
9.3.2 Advanced cleaning
This section describes a cleaning procedure for aggressive cleaning of
LightGuide flow cells.
All chemical reagents should be of at least ACS-Grade, preferably
HPLC-Grade. This procedure involves the use of caustic and flammable
reagents (“General safety instructions”).
#1: 0.5 M Potassium Hydroxide in 100% Ethanol (briefly, 7.013 g KOH
in 250 ml EtOH). After thorough mixing, the solution should be filtered
through a 20 µm pore size filter.
#2: 100% Methanol
#3: Ultrapure water, Type I per ASTM D1193-99 or equivalent.
Note:
Grade 1 ultrapure water per ISO 3696 differs significantly from the
above classification.
The cleaning solutions #1, #2 and #3 are readily prepared.
The flow cell is installed in a detector.
2 syringes with appropriate volumes (about 10 ml) or a peristaltic pump
Note:
It is imperative that Solution #2 immediately follow Solution #1 to
remove residue remaining on the optical components. Failure to do so
will result in poor flow cell performance.
Note:
It is recommended the peristaltic pump is configured to “pull”
through the cell to avoid possible contamination from degraded peristal-
tic pump tubing. To lessen the time required for this cleaning method,
large bubbles of air can be introduced into the flow cell alternately with
the cleaning solutions. This method uses a laminar flow profile and radial
diffusion to effectively “scrub” the inside of the flow cell.
Note:
Observe the extent of performance improvement in the Diagno-
stics window throughout the entire process.
Process with pump
Process 1
1.
Flow each cleaning solution through the flow cell in numerical
order.
2.
Cycle each solution for approximately 3–4 minutes, with a bolus of
air introduced between each solution. The flow direction can be
rever sed between cycles to ensure thorough cleaning.
3.
Repeat the procedure until there is no noticeable improvement in
sample cell performance.
4.
Continue with the “Final Rinsing Process” below.
Next step
Preparation
of chemicals
Cleaning solutions
Prerequisites
Tools
