5.1. Defining Sample Volume

Try these first

1. 1.

   What is sample volume?

   Hint

   Consider why we specify volumes in experiments.

2. 2.

   Why is concentration expressed as mass over volume?

   Hint

   Reflect on how pollution is measured.

3. 3.

   What is the primary goal of sampling in environmental analysis?

   • To find the average value
   • To obtain accurate concentration measurements
   • To measure temperature

   Hint

   Think about what decisions are made from sampling data.

4. 4.

   True or False: The detection limit is the same as the sensitivity of an instrument.

   • True
   • False

   Hint

   Recall the definitions of these two terms.

5. 5.

   You are tasked with monitoring water quality in a lake with known low levels of phosphorus. Your instrument has a detection limit of 0.5 mg/L, and preliminary studies suggest phosphorus levels could be around 0.2 mg/L. Describe the steps you would take to determine the sample volume needed for reliable measurements.

   Hint

   Consider the volume-to-concentration ratio needed to surpass the detection limit.

6. 6.

   A water sample has been filtered to measure suspended solids. You find different masses in repeated measurements; what could explain this discrepancy?

   Hint

   Think about sample collection consistency and instrument reliability.