Development of a portable setup using a miniaturized and high precision colorimeter for the estimation of phosphate in natural water

Abstract

In this work, a high integrated water detection system comprised a miniaturized and high precision homemade colorimeter, a microfluidic analysis module and a wireless module was reported. A reagent reaction based on the ammonium molybdate spectrophotometric method was recorded for the estimation of phosphate in natural water. A laser self-modulating module of 880 nm was used as the radiation source. A microfluidic chip was employed to fit the colorimeter with an optimized micro flow path for low liquid consumption and high precision detection. The wireless module consisted of two parts, using ZigBee and GSM modules to realize short and remote displaying and controlling. Applying a novel optimized algorithm, a wide linear response was obtained ranging from 0.02 up to 9.5 mg L−1. The optimization of colorimeterare mainly in the core detection part, allowing an improvement of the detection limit, achieving a result of 0.009 mg L−1. A low reagent consumption of 0.004 mg ascorbic acid and 0.011 mg ammonium molybdate for per determination was attained. Experimental results have also shown that the system could maintain good stability among broad room temperature changing from 17 °C to 35 °C with less energy consumption. The miniaturized colorimeter-based water detection system opens new avenue for operating in remote distance to get high precision measurements of phosphate in natural water.