DelAgua OXFAM-DELAGUA, Руководство пользователя

Страница: 35 / 67

OXFAM-DELAGUA Water Testing Kit — Users Manual
34
Other Water Sources
Recommended sample volumes for each source are shown below.
Suggested sample volumes for thermotolerant coliform analysis by the
membrane filtration technique (alternative volumes are shown in brackets).
Source
Sample volume
Lakes, ponds and other surface waters 10ml (1ml*)
Protected groundwater, eg. wells and
springs 100ml (50ml or 10ml)
Unprotected groundwater, eg. open dug
wells and springs 50ml (10ml or 1ml*)
*Note: This volume will require the use of sterile pipettes and dilution water.
Please note, these volumes are only a guide. They do not represent absolute
recommendations to be applied to sampling programmes. It may be useful to
analyse different volumes of the same sample in order to decide the best range in
which to count the bacteria. It is not necessary to sterilise the filtration apparatus
and sample cup between two analyses of the same sample provided that the smaller
volume is processed first.
5.4.4 Sample Processing for Thermotolerant (Faecal) Coliform Analysis.
1.
Using the absorbent pad dispenser,
place one pad into each petri-dish (this
operation may be done at base before
leaving for the field). If the dispenser
is damaged, the pads can be dispensed
using the sterilised tweezers.
Dispense one pad into each petri dish