For how long should the RPC strip be immersed in the sample?

The correct duration for immersing the RPC strip in the sample is 60 seconds because this timeframe ensures optimal exposure to the analyte in the water sample. Immersing the strip for this specific time allows the reactive materials on the strip to adequately interact with the sample, leading to accurate results.

Immersion for too short a period might not provide enough time for the chemical reactions to occur, potentially resulting in false negatives or inaccurate readings. Conversely, extending the immersion time beyond the prescribed 60 seconds can also affect the results, possibly leading to saturation or interference from excessive sample exposure. Therefore, the 60-second immersion is critical for maintaining the integrity and reliability of the test results.