Metrohm 909 UV Digester - Manual (Page 9)

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1 Introduction
909 UV Digester
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1 Introduction
1.1 Instrument description
The 909 UV Digester is used for the digestion of aqueous samples moder-
ately loaded with organic material. Its primary use is sample preparation
for analyses in voltammetry, ion chromatography, AAS and ICP-AES. The
digestion of samples is based on the photolytic generation of hydroxyl
radicals, whose formation is initiated by a hydrogen peroxide radical initia-
tor. The hydroxyl radicals immediately react with the organic compounds
and work to break them down. The temperature and time for digestion
can be entered conveniently using the operating unit. The temperature is
controlled automatically using air cooling and the UV lamp's emitter
power (medium pressure mercury lamp), which is regulated between
100% and 50% as needed.
The 909 UV Digester combines the wet end and control unit in one hous-
ing. The UV lamp is located in the center of the wet end. The sample ves-
sels are inserted in the sample holder encircling the UV lamp. The fan for
air cooling is located in the lower portion of the wet end. The control unit
consists of the operating unit and all of the electronics including the elec-
tronic ballast for regulating the UV lamp. The 909 UV Digester is used as a
standalone instrument.
1.1.1 Supply voltage
The 909 UV Digester can be operated only with a supply voltage of 220 to
240 V. Therefore, for a supply voltage of 100 to 120 V, a transformer has
to be connected between the power and the instrument. You can find
details on the transformer's specifications in Chapter Technical specifica-
tions, page 39.
1.1.2 Intended use
The 909 UV Digester is a sample preparation instrument that can be used
in analytical laboratories for preparing samples for the following analysis
processes:
￭ Voltammetry
￭ Ion chromatography
￭ AAS
￭ ICP-AES
Chemicals and flammable substances can be used as a sample additive or
auxiliary reagent in this instrument. Usage of the 909 UV Digester there-
fore requires the user to have basic knowledge and experience in handling
toxic and caustic substances. Knowledge with respect to the application