Which action helps minimize evaporation of sample volume during collection and handling?

Which action helps minimize evaporation of sample volume during collection and handling?

• A. Keep cap on the tube
• B. Remove cap to check volume
• C. Warming the sample
• D. Rapidly shaking

Answer: (A)

Minimizing evaporation centers on limiting the liquid’s exposure to air. Keeping the cap on the tube seals the sample, preventing vapor from escaping and helping maintain the original volume and concentration. Removing the cap to check volume temporarily increases exposure and allows evaporation to occur. Warming the sample raises vapor pressure and speeds evaporation, while rapid shaking can cause splashing and increase the surface area, promoting more loss. Therefore, keeping the cap on is the best way to minimize evaporation during collection and handling.

Minimizing evaporation centers on limiting the liquid’s exposure to air. Keeping the cap on the tube seals the sample, preventing vapor from escaping and helping maintain the original volume and concentration. Removing the cap to check volume temporarily increases exposure and allows evaporation to occur. Warming the sample raises vapor pressure and speeds evaporation, while rapid shaking can cause splashing and increase the surface area, promoting more loss. Therefore, keeping the cap on is the best way to minimize evaporation during collection and handling.