A Carbon Dots-Based Coating For The Determination Of Phthalate Esters By Solid-Phase Microextraction Coupled Gas Chromatography In Water Samples

A rapid and facile route is followed to synthesize carbon dots (CDs) immobilized on the surface of steel wire from candle soot (CS) for the efficient and selective determination of phthalate esters (PAEs) as solid phase micro extraction (SPME) coating. Five PAEs were selected as target analytes and detected through a head-space SPME mode coupling with gas chromatography-flame ionization detection (GC-FID) from aqueous samples. The effects of various factors on the extraction efficiency, such as extraction time, extraction temperature, salt content and stirring rate, were optimized through orthogonal experiment. Under the optimal conditions, the fiber showed a good linear in the concentration range of 1.0-500 mu g.L-1 (R-2 > 0.9909). The limit of detections (LODs) and quantifications (LOQs) ranged from 0.32 to 3.13 mu g.L-1 and 1.07-10.43 for five PAEs, respectively. The relative standard deviation (RSD) of intra-day and inter-day for these PAEs at a concentration level of 10 mu g.L-1 (n = 5) were 3.7-8.6% and 5.6-13.3%, respectively. The prepared fiber can be repeatedly used more than 50 times, showing a long lifetime and good stability. The proposed method had been successfully applied to the analysis of PAEs in real water samples with recoveries varied between 82 and 119%.