Metrohm 757 VA Computrace - Manual (Page 58)

4 Safety
757 VA Computrace – Hardware
54
• Trapping of mercury drops
Single mercury drops in this drip pan or any other spilt mercury can be bound
in a simple manner by amalgamation:
− with silver (Ag):
Metrohm drop catcher Type 6.2406.000 which is included
in the standard outfit of the 757 VA Computrace Stand
− with tin (Sn):
e.g. the thin tin foil supplied by Merck, Darmstadt/FRG
− with special laboratory aids:
e.g. Mercurisorb-Roth from Roth, Karlsruhe/FRG; e.g. Mercury
Sponge and Resisorb from Baker, Phillipsburg, N.J./USA
• Empty reservoir of mercury trap regularly
The storage container 4 of the 6.2406.000 mercury trap should be emptied
regularly and rinsed thoroughly several times. If the mercury trap is needed
outside the fume cupboard, a minimum safety distance of 50 cm between the
head and the mercury trap must be observed.
• Never leave mercury in open vessels
Mercury must never be left exposed to the air. The upper layer of water or
supporting electrolyte in no way suppresses nor reduces Hg evaporation [11,
12].
• Store mercury container in fume cupboard
The tightly closed mercury container as well as all parts which come into con-
tact with mercury must be stored in a fume cupboard which is always
switched on.
• Use gas wash bottles when siphoning off mercury under vacuum
If mercury is siphoned off under vacuum using a water jet pump, one or two
gas wash bottles must always be connected between the vacuum pump and
the suction tube to ensure trapping of the siphoned-off mercury.
• Ventilate laboratory areas well
Rooms where work with mercury is being carried out should be thoroughly
aired from time to time.
• Dispose of mercury properly
Mercury can be cleaned by distillation [13 – 16], but the apparatus is exten-
sive and the time needed considerable. For this reason, waste mercury is
normally collected in a closed container and then sent for disposal to the re-
sponsible authorities in accordance with the national legal requirements.