Conductometric Determination of Ammonium in Turbid Water with a Flow-batch Porous Membrane-based Diffusion Scrubber System

A porous membrane-based diffusion scrubber was fabricated to couple with a conductometric detector as a flow-batch system for determining ammonium in turbid surface waters. A gravity flow of DI water as a gas absorbing liquid and a manual sample introduction was employed to develop a costeffective device without using a conventional pump and an injection valve. The standard calibration graph was linear in the range of 5 - 100 mu mol L-1, with a relative standard deviation of < 5%. The detection limit based on the lowest concentration in the calibration graph of 5 mu mol L-1 can be obtained. The results of ammonium determination using the proposed method agree well with those using the batch-wise indophenol blue as a standard method. The proposed analytical system provides a cost-effective setup and easy operation for ammonium determination in some turbid surface waters samples without requiring a filtering process and conventional glassware.

Automated summary

A porous membrane-based diffusion scrubber coupled with a conductometric detector was developed as a flow-batch system for determining ammonium in turbid surface waters. The method utilized a gravity flow of DI water as absorbing liquid and manual sample introduction, resulting in a cost-effective device without the need for a conventional pump and an injection valve. The standard calibration graph showed a linear relationship in the range of 5-100 µmol/L with a relative standard deviation of less than 5%. The proposed method provided a detection limit of 5 µmol/L based on the lowest concentration in the calibration graph. The results obtained using the proposed method matched well with those using the batch-wise indophenol blue as a standard method. This analytical system offers a cost-effective setup and easy operation for ammonium determination in turbid surface water samples, eliminating the need for a filtering process and conventional glassware.