Methods

Dissolved Oxygen: Sample Collection and Fixing
1) Collect water as described above using a clean and thoroughly rinsed container.

2) Fill and cap the glass sample bottle ensuring that no air bubbles are trapped inside.

2a) If using a LUMCON-style sampler, immediately cap the glass bottle located inside the sampler.

2b) If using an open top sampler, such as a bucket, hold the glass bottle underwater until all air is removed then cap while the bottle is still submerged.

3) Put on gloves and safety glasses before proceeding to the next steps. Your procedure will vary with the type of oxygen kit available.

Important steps to remember: Wear gloves and goggles whenever handling chemicals. Rinse the sample bottles at least 3 times. Add the reagents to the sample in the proper order. Do not shake the reagent bottles or sample. Mix by slowly turning the bottle over several times. Do not touch the reagent bottles to each other or to the sample. When adding reagents, hold the bottle or dropper vertically not at an angle. Be sure there are no bubbles in sample or titrator.