What is the purpose of using a trip blank in water sampling?

The purpose of using a trip blank in water sampling is to check for contamination during the sampling process. A trip blank is essentially a sample container filled with deionized water that is transported along with the actual water samples but is not exposed to the environment from which the samples are taken. By analyzing the trip blank after the sampling event, it can be determined if any contaminants entered the sample due to the handling, transportation, or other processes that occurred prior to analysis. This is crucial for ensuring the integrity of the water samples and for confirming that any detected contaminants in the actual samples are not the result of external contamination, thus providing reliable and accurate data.