CETAC M-7600 Mercury Analyzer Operator's Manual

Operator’s Manual
Chapter 4: Using the Analyzer
NOTE
The CETAC QuickTrace M-7600 mercury analyzer measures inorganic mercury
(free Hg 2+ or HgCl 2 , which is subject to efficient stannous chloride reduction in
the QuickTrace M-7600 tubing reactor). Inorganic mercury standard solutions
are used for instrument calibration. If insoluble mercury, bound mercury, or
organomercurials are present in samples, an appropriate sample
dissolution/digestion procedure will have to be employed to convert these
forms to free inorganic Hg 2+ or HgCl 2, prior to analysis with the QuickTrace M-
7600. If it is desired to confirm the oxidative digestion procedure accuracy
(recovery) regarding organomercurials, then organomercurial standards or
appropriate standard reference materials would have to be carried through the
digestion as “process standards”.
WARNING
ORGANOMERCURIAL EXPOSURE HAZARD
The handling of organomercurial concentrates, which may be used in the
preparation of process standards, presents a substantial (potentially lethal)
safety hazard. Only an experienced, professionally trained organo-metallic
chemist, knowledgeable and skilled specifically in the safe handling of
organomercurials (using approved apparatus and approved protection
measures in an approved facility) should attempt to prepare diluted
organomercurial process standards from concentrates. Always be sure to
obtain and carefully read the MSDS (Material Safety Data Sheets) before
handling organomercurials!
Always wear appropriate personal protective equipment when operating
the mercury analyzer or handling organomercurials. At a minimum, you
should wear eye protection, acid-resistant gloves, and a lab coat.
NOTE:
CETAC Technologies assumes no liability for the handling of organomercurial
concentrates or the preparation, handling, or use of diluted organomercurial
process standards.
In most cases, CETAC Technologies recommends that samples be oxidized
following standard, safe, well known, approved sample dissolution or digestion
procedures, and that the QuickTrace M-7600 instrument calibration
standards be prepared only from inorganic mercury concentrates or diluted
from commercially available inorganic mercury standard solution
concentrates. Where possible, the recommended means of overall process
(dissolution/digestion + QuickTrace M-7600 analysis) validation should be
through use of commercially available standard reference materials (SRM’s) of
composition matching (or similar to) the samples and containing certified,
known mercury levels in a concentration range similar to the samples. (Being
by far the safest alternative, this SRM approach to overall process validation
should be used whenever possible, and is nearly always preferred to preparing
diluted process standards from hazardous organomercurial concentrates!)
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