Lab-Made Semi-Automated Microfluidic Flow Injection Spectrophotometric System for Determination of Nitrite in Natural Water

A lab-made semi-automated microfluidic flow injection spectrophotometric system for the determination of nitrite in natural water was constructed and designed. It has consist of double line microfluidic chip with dimensions (40µl×5cm), each one 20 µl volume aims to allow very small volume from reagent and sample to be used. The microfluidic system also, consists of two Arduino microcontroller programs. The first one was UNO used to dominance mini peristaltic pump and the other one was a mega type which was records the results as peaks using Microsoft Excel 2010 program. The linearity was ranged (0.025-0.15) μg/ml with regression coefficient of six points 0.9997, r.s.d% for ten replicates of 0.1 μg/ml. The detection limit was 1.75 ng/ml and the samples throughput was 150 samples per hour and one sample required 55.7µl of chemical reagents therefore, 150 samples consumed 8.355 ml of chemical reagents which clearly indicated that the consumed reagent and waste were very low.So, the method of determination of nitrite in this system is Eco-friendly. The concentrations of nitrite in the natural water were in the range (0.025-0.4) μg/ml.