Samples must be analyzed immediately after collection and cannot be preserved for later analysis. 

Let the sample temperature decrease to 50 °C (122 °F) or less before analysis. 

Sulfite reacts quickly with oxygen in the air. Shaking or swirling the sample causes low results. Prevent agitation of the sample during the procedure. 

Review safety chemical handling procedure. Use the recommended personal protective equipment. Dispose of reacted solutions according to local, state and federal regulations. Follow the environmental safety, health safety staff for your facility and/or local regulatory agencies for further disposal information.