Which statement best describes the purpose of a travel blank in VOC sampling?

Which statement best describes the purpose of a travel blank in VOC sampling?

• A. To check for contamination introduced during sampling or transport
• B. To calibrate the GC detector
• C. To verify the sample's final VOC concentration
• D. To standardize pH adjustments

Answer: (A)

In VOC sampling, a travel blank is used to detect contamination that can be introduced during the sampling process, handling, or transport. It’s prepared and carried through the same steps as the actual sample but isn’t exposed to the source material. If the travel blank shows VOCs, it signals that the sampling or transport process itself added contaminants, so the true environmental result may be questionable. This is distinct from calibrating an instrument or verifying the sample’s concentration; those tasks rely on standards and the actual sample analysis. It’s also not about adjusting pH, which isn’t a factor in most VOC sampling workflows. So the travel blank’s purpose is to reveal contamination from sampling or transport, making it the best choice.

In VOC sampling, a travel blank is used to detect contamination that can be introduced during the sampling process, handling, or transport. It’s prepared and carried through the same steps as the actual sample but isn’t exposed to the source material. If the travel blank shows VOCs, it signals that the sampling or transport process itself added contaminants, so the true environmental result may be questionable. This is distinct from calibrating an instrument or verifying the sample’s concentration; those tasks rely on standards and the actual sample analysis. It’s also not about adjusting pH, which isn’t a factor in most VOC sampling workflows. So the travel blank’s purpose is to reveal contamination from sampling or transport, making it the best choice.