Micropipette Tip-Assisted Cobalt Based Nanofibers for Selective Micro-Solid Phase Extraction of Rhodamine 6G from Water and Food Samples

A facile and green micropipette tip-assisted micro-solid phase extraction (MPT-µSPE) method coupled with UV-vis spectrophotometer for quantification of Rhodamine 6 G (Rh6G) in food and cosmetic samples was established. Electrospun was prepared from a Zeolitic Imidazolate Framework (ZIF-L(Co) modified with polyacrylonitrile (PAN) solution applied to an electrospinning unit. Micro-solid phase extraction parameters, such as sample pH value, sample volume, nanofiber dimension and elution solvent type were investigated. The combination of MPT-µSPE with UV-vis spectrophotometer exhibited a linear range of 5.3–3000 µg L−1, low detection limit (LOD) 1.7 µg L−1 and preconcentration factor (PF) of 10. The precision tests of the method upon Rh6G extraction resulted in 2.1% intraday and 2.7% interday. To evaluate the environmentally friendliness and environment sustainability of the method in a standardized and transparent way, Analytical GREEnness Metric Approach (AGREE) and Analytical Greenness Metric for Sample Preparation (AGREEprep) were evaluated demonstrating 0.68 and 0.75 respective scores. The suggested method was successfully applied to quantify Rh6G at trace levels from some fruit juices, nail polish and skin care products with recoveries ranging 92%–114% and relative standard deviation (RSD) of 2.3%.