On-line carbon dots synthesis using flow injection analysis. Application to aluminium determination in water samples

An on-line synthesis of CDots is proposed for the first time, using the flow injection analysis (FIA) technique, which was coupled, in a single system, to the analytical determination of aluminium in water samples. The nanoparticles were obtained from the carbonization of glucose and iron(III) in an acidic medium, and their photoluminescence increased in the presence of aluminium ions. Under optimal experimental conditions, the proposed method has shown an acceptable linearity range -between 0.04 and 3.0 mg L-1 (R2 = 0.9999) - and a detection limit of 0.007 mg L-1. The analysis of drinking water and groundwater samples showed good accuracy (recoveries ranged between 91 - 113%) and RSD% < 13. The on-line system exhibited a high sample throughput (36 h-1), since no incubation time was required.

Automated summary

For the first time, an on-line synthesis of CDots is proposed using the flow injection analysis (FIA) technique for the determination of aluminium in water samples. The nanoparticles were obtained from the carbonization of glucose and iron(III) in an acidic medium, and their photoluminescence was enhanced by aluminium ions. The proposed method showed good linearity (R2 = 0.9999) within a range of 0.04 - 3.0 mg L-1 and a detection limit of 0.007 mg L-1. The analysis of drinking water and groundwater samples demonstrated accurate results with recoveries ranging from 91 to 113% and RSD% < 13%. The on-line system exhibited a high sample throughput of 36 h-1 without the need for incubation time.