Which practice enhances reliability of field data during sampling campaigns?

• A. Skipping blanks to save time
• B. Collecting only surface samples
• C. Field blanks and proper decontamination procedures
• D. Avoiding calibration of instruments

Answer: (C)

In field sampling, reliability comes from QA/QC steps that reveal and minimize contamination and carryover during collection and handling. Field blanks are treated the same way as real samples, but they contain clean material (for example, deionized water or blank matrix) and are processed through the entire sampling and analysis chain. If contaminants appear in these blanks, it signals that contamination is being introduced in the field or during sample processing, allowing you to account for it or flag affected data. Coupled with proper decontamination procedures—thoroughly cleaning or dedicating equipment between samples to prevent residue from one sample influencing the next—you greatly reduce cross-sample contamination. Together, these practices make the measured results more trustworthy and reflective of the true field conditions.

Skipping blanks hides potential contamination; collecting only surface samples can bias results and miss variability at depth or in different layers; avoiding calibration leaves instruments susceptible to drift and inaccurate readings.