Sulphate is naturally occurring and found in numerous minerals.

Taking a water sample
The analytical result is only as good as the sample submitted for analysis. Collecting a representative sample is the first step of the analytical procedure.
Clean tap thoroughly, including the inlet with a flame or disinfectant wipe.
Turn on the tap and allow water to run for a minimum of 2 minutes.
Take the cap off the sterile bottle and immediately fill the container.
Replace the bottle cap as soon as the bottle is full (leaving a small headspace) and record the site and date of sampling.
Deliver to the IEC as soon as possible.
Maintain the water samples at 1-5°C if storing overnight.