Detection of humic acid in water using flat-sheet and folded-rod viscous alkaline glucose syrups

The utility of a low-cost biocompatible material for the detection of pollutants in water is highly essential to ensure safety and economic efficiency. In this paper, solutions of two viscous alkaline glucose syrups (AGS@22-sheet and AGS@60-rod), obtained under two different temperature conditions (22 °C and 60 °C) were used to detect low levels of humic acid (HA), a carcinogen pro-molecule and metal-complexing agent in an aqueous solution. The AGS materials were characterized using ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy and scanning electron microscopy (SEM). By evaluation, a detection limit (LOD) as low as 4.6 × 10^-5 mg L^-1 was obtained. The sensing capability of the new technology was further extended to the detection of HA in a real water sample (tap water) using the standard addition method with 98 and 100.05% recoveries. The sensing was improved in the presence of sodium acetate and sodium citrate and was found to follow a pseudo-first order reaction. These findings show that the as-synthesized glucose syrups have the potential to detect humic acid in water and thus may be employed for the quantification of HA in water treatment plants or textile industry.