Last updated on July 2017
LABORATORY OF ENVIRONMENT AND FOOD SAFETY
I. MICROBIOLOGICAL ANALYSIS
1.1. Individual parameters
Culturable microorganisms at 30°C
NF EN ISO 4833-1
NF EN ISO 7932
NF EN ISO 10272
NF ISO 4832
NF ISO 21528
NF ISO 16649
Yeast and Molds
NF EN ISO 6579
Spore of thermophilic aerobes
GUIRAUD – 1998
Spore of thermophilic anaerobes
GUIRAUD - 1998
NF EN ISO 6888-1
1.1.2 Water samples
Culturable microorganisms at 22 °C and 37°C
NF EN ISO 6222
NF EN ISO 9308-1
NF EN ISO 9308-1
NF EN ISO 7899
Spores of sulfite reducing anaerobes
NF EN ISO 16266
1.2 Standard analysis in food and water samples
2. PHYSICO-CHEMICAL ANALYSIS
2.1. Individual parameters
Chemical Demand of O2 (COD)
Total Suspended Solid (TSS)
Total Dissolved Solid (TDS)
2.2. Standard analysis in water samples
Type of analysis
Turbidity, pH, Chloride, Ammonium, Nitrites, Nitrates, Total Hardness and Iron
Swimming pool water
Turbidity, pH, Chloride, Ammonium, Nitrites, Nitrates, Total Hardne, Iron, Total Chlorine, Free Chlorine
3. COMBINED STANDARD ANALYSIS OF WATER
Type of analysis
Culturable micro-organisms at 22oC and 37oC, spores of sulfite reducing anaerobes, Total coliform bacteria,
Swimming pool water
Culturable micro-organisms at 22oC and 37oC, Sulfite reducing anaerobes, Total coliform bacteria,
Turbidity, pH, Chloride, Ammonium, Nitrites, Nitrates, Total Hardness, Iron, Total Chlorine, and Free Chlorine
Culturable micro-organisms at 22oC and 37oC, Sulfite reducing anaerobes, Total
Turbidity, pH, Chloride, Ammonium, Nitrites, Nitrates, Total Hardness, and Iron
4. FOOD CHEMISTRY
Organophosphate group, carbamate group, organochlorine, synthetic pyrethroid cholinesterase inhibitors
Recommendation concerning the conditions of sampling, packaging and transportation of water samples for microbiological analysis. These recommendations are in accordance of the following international standards:
- NF EN ISO 5667-3: Preservation and handling of water samples
- NF EN ISO 19458: Sampling for water analysis
- FD T90-520: Guide technique de prélèvement pour le suivi sanitaire des eaux en application du code de la Santé Publique (réglementation française)
5.1 General recommendations
- The customer must make an appointment with the laboratory specifying the type of water analysis and microbiological parameters requested.
- Written guidelines/procedures/methodology in Khmer and in English to collect the samples and recommendations for their storage/transportation are available in the LFMWA and could be requested by the customers at the Lab reception.
Sterile vials for single use polyethylene are available for samples with a capacity ranging from 500 ml, 1000 ml to 2000 ml. – these bottles are added or not of sodium thiosulfate to a final concentration of 20 mg/l.
- Container labels should withstand wetting, drying and freezing without detaching or becoming illegible. The labelling system shall be waterproof to allow use on site.
- The exact information given in the sampling report and on the sample labels depends on the objectives of the particular measurement program. In all cases, an indelible label shall be secured to the sample container. For each sample, at least the following information shall be available.
— date, time and location of sampling
— sample number
— description of sample
— name of sampling personnel
— details of sample preservation, or fixation used;
— details of sample storage used
— any information regarding integrity and manipulation of the sample;
— any other information, as necessary
__ a unique identifier, traceable to sample date, location, and sample number shall appear on the label of the sample container
__ all other information are supplementary and should be detailed in the sample report
5.2 Conditions of transport and storage
- Keep the time between sampling and analysis in the laboratory as short as possible. For drinking waters.
- Analysis should ideally be started within the same working day.
- Cool samples — ideally (3-5) °C — during transport (e.g. by using ice packs or melting ice), unless otherwise stated in specific standards. Take care not to freeze them (except for viruses). Protect samples from Sunlight.
- For samples transported for periods over 8 h, it is necessary to monitor and record the temperature.
For samples transported for periods over 8 h, it is necessary to monitor and record the temperature.
Transport conditions shall be documented. Nevertheless be careful:
Document the procedure required for longer transport times (8 h).
- Warm and cold samples shall be transported separately.
5.3 Delivery time of samples to the laboratory
- The following table provides a chart of recommendations for the maximum period of delivery. The times listed are estimates: they depend on the type of water, the physiological state of microorganisms (eg disinfection or not) and the methods.
- In case of delay exceeding the recommended time of delivery, the results must be interpreted carefully and subject to control by another analysis.
Recommended (R) & acceptable (A) values
For maximum sample storage times including transport time
& temperatures unless otherwise specified in specific standards
Maximum sample storage time
(h) including transport
Storage water temperature (°C)
Culturable microorganisms (22, 30 or 36 °C)
Faecal indicators, vegetative bacteria
- E. coli (and coliform bacteria)
- Clostridium perfringens (vegetative cells)
Spores of sulfite-reducing bacteria
Die-off observed in raw waters after 24 h
Salmonella spp. and other Enterobacteriaceae
Sample stabilized at pH = 2