Metrohm NIRS XDS RapidLiquid Analyzer - Manual (Page 28)

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5.3 Cuvette Types
The Rapid Liquid Analyzer is preferred for samples
of these types:
• Non-volatile samples, run in open or
capped cuvettes.
• Volatile samples, run in sealable cuvettes.
Path length information:
As a rule, aqueous samples require path lengths of
0.5mm, 1mm, or at most 2mm, depending up on
absorbance of the analyte. The water bands begin
to dominate the spectra at path lengths over 0.5
to 1mm.
Polyol spectra may require longer path lengths, on
the order or 4mm, 10mm, and 20mm. Because
polyols generally contain very little water, the
longer path lengths work well, and provide good
detection of additives in the sample matrix.
Perform some initial analysis with cuvettes of
various path lengths to determine optimal path
length for your analysis.
Cuvette Type:
Open or capped cuvettes may be used with non-
volatile compounds, where the constituents will
remain in solution for the duration of analysis, and
evaporation is not an issue.
Compounds with volatile ingredients should be
analyzed in sealable cuvettes, to prevent loss of
constituents to the atmosphere.
Capped cuvette assortment. Sizes are 0.5mm,
1mm, 2mm, 4mm, 10mm, and 20mm path
length.
Sealable Cuvettes: Sizes are 2mm, 4mm.
10mm and 20mm.
Safety Precautions:
Always use appropriate safety equipment with
hazardous materials, to prevent injury. This
equipment may include safety glasses, gloves,
lab apron, and fume hood.
Always check the MSDS (Material Safety Data
Sheet) for the materials being analyzed for
recommended handling precautions.
5.4 Flow-Through Fittings
Metrohm has provided flow-through bulkhead fittings on the door
of the XDS Rapid Liquid Module for users who require analysis of
flowing liquids.
These ports may be attached, using flexible tubing, to a suitable
cuvette or cell which fits into the sample drawer. It is important to
use tubing that is compatible with the analyte.