Q2

What is the recommended sequence of sampling locations when investigating a ground-water contaminant plume?

• Start randomly at different locations

• Start from down gradient and work up gradient

• Start from the most contaminated location

• Start from up gradient and work down gradient

Why is it important to collect water before sediment when sampling both at the same site?

• To minimize effects from suspended bed materials

• To reduce the accuracy of the results

• To increase potential cross-contamination

• To speed up the sampling process

What should be collected first when sampling at different water depths?

• Microbiological samples

• SVOCs

• Inorganic nonmetals

• VOCs

Why should taking too large or too many samples be avoided?

• To speed up the analysis process

• To complicate the sampling procedure

• To increase the accuracy of the results

• To reduce storage, transportation, and disposal costs

What is the minimal liquid sample volume needed for TPHs in liquid wastes?

• 10 L

• 5 mL

• 100 mL

• 1 L

How much dry mass of soil is generally sufficient for contaminant analysis?

• 20 g

• 500 g

• 50 g

• 200 g

Why is the required sample size for sediment smaller than water samples?

• Sediment is easier to analyze

• Sediment is less important in environmental analysis

• Contaminants tend to accumulate in sediment

• Sediment requires less preservation

What is the purpose of sample preparation in trace analysis?

• To dilute the analytes

• To increase the sample volume

• To homogenize sample or remove moisture

• To speed up the analysis process

What is the basic principle behind solid-liquid extraction techniques?

• Partitioning between liquid and solid phases

• Heating the sample to high temperatures

• Freezing the sample before extraction

• Adding preservatives to the sample

What is the purpose of sample decomposition/degradation?

• To increase analyte concentration

• To remove interfering chemicals

• To liberate analyte from sample matrix

• To change sample phase