All samples must be protected from sunlight and cooled on ice at 0-4°C immediately after collection and maintained at 0-4°C until analysis. Storage in pre-chilled cold boxes is adequate for short transfer times. Ideally, the samples should be processed and tested onsite to give the quickest results. Samples must be analysed within <5 days from the time of collection.
If the on-site tests are above threshold values, then do ensure you have a sample container to take an additional field sample for laboratory analysis. Commercial laboratories often require 1000 ml (one litre) of sample for cyano-toxins, but a dark bottle container for algae cell analysis.
Remember, prior to testing the water sample, a smaller sample of water needs to be raised to room temperature. This is listed in the user guide for each test.
For specific notes on storage and transport of the samples, if testing cannot occur onsite, please reference to the following documents:
Sampling Method Sheets
The process of collecting water samples is straight forward. If you are collecting and testing filtered water, the process is simplified, but taking a clean water sample from the lake is sometimes not so straight forward. Advice is given on water sampling and on the measurement of cyano-toxins in the following method sheets.
If you are collecting unfiltered drinking water, then by taking a sample of water from the location of the water inlet is advisable. This should be done safely and with gloved hands. If you are collecting filtered drinking water, then take the water sample from a tap just after the mechanical filter, but before any chlorination.
If the sample is for recreational water tests, then samples are normally taken at the access point to water, namely a pier or at the access steps into the water. For Triathlon events, samples should be taken from the starting pontoon platform. Again, for livestock, water samples should be taken from their access point.
Ideally, samples should be taken from the first 20cm of water and from water more than 40cm deep. Try to ensure that no silt enters the water. If that proves difficult, or unsafe, we recommend using a simple bailer system.
For routine weekly samples, we recommend the sample is taken 2 hours prior to recreational users entering the water. This gives enough time to undertake the test and react should the test show cyano-toxins being present in the water. If the sample is for weekly testing of drinking water, we would recommend taking the sample early in the morning, after any algae have died back overnight.
Please remember, the test determines the presence or absence of the toxins. The sample may look clean, but the blue-green algae bloom could be in another location of the lake and not visible, but the toxins will diffuse through the lake quickly.
In most cases, sample bottles are not re-used, but re-cycled. If you need to clean the bottles, then seek laboratory advise. Cleaning of sample containers is acceptable as long as you can demonstrate the effectiveness of the cleaning procedure. This is normally done by collecting and analysing the deionised cleaning water in 5% of the cleaned containers. Obviously, this water must test clean. Keep records of this process, if you re-use sample bottles.
A minimum of 100 ml should be collected in a glass or polyethylene terephthalate glycol (PETG) container. Most plastic containers will show the material specifications as part of the recycling symbol on the base of the container.
Samples treated with chlorine or any other oxidiser (e.g. KMnO4, NaMnO4) must be quenched with 10 mg sodium thiosulfate or ascorbic acid added per 100 mL of sample during collection. For field tests, it this therefore strongly advised to take the water sample before chlorination. Please remember to follow COSHH regulations. BGAS does not supply de-oxidising solutions.
Vets may come across pets / livestock suffering from potential cyano-toxicity. Pet / livestock owners could be encouraged to bring a water sample to the vets for the vets to administer the cyano-toxin tests on the samples. This assumes that the owner has safe access to the water. Ideally the sample should be collected in a glass bottle, which the vets might supply. Please speak to BGAS about practice rates for group orders.
The company is able to offer proficiency training on the test strips for groups of users. These training days will be support by Abraxis. Please contact us by email.