How much of the sampler bottle should be filled with liquid when composing a composite sample?

• A. 1/4 to 1/2
• B. 3/4 to full
• C. 1/8
• D. All of it

Answer: (A)

When composing a composite sample, you’re collecting multiple portions over time into one bottle. Leave headspace so you can add all portions and then mix without spilling. Filling about a quarter to a half of the bottle provides room for the remaining aliquots and for mixing, while minimizing the risk of overflows during handling. Filling closer to full makes it hard to add later portions and increases spill risk. So, aim for roughly 1/4 to 1/2 full.