Natural deep eutectic based dispersive liquid-liquid microextraction and solidified floating organic drop for cadmium determination by electrothermal atomic absorption spectrometry with multivariate optimization (DLLME-SFOD-NADES-ETAAS)

A novel method was developed for cadmium determination based on dispersive liquid-liquid microextraction and solidified floating organic drop by multivariate optimization with electrothermal atomic absorption spectrometric detection using a natural deep eutectic solvent (NADES) of (L)-menthol and formic acid. Important factors, including pH, final concentration of PAN, mole ratio of formic acid, volume of NADES, type of dispersive solvent, and vortex time, were assessed using two-level fractional factorial design (FFD), and circumscribed central composite design (CCC). The analytical performance parameters, encompassing linearity range, limit of detection (LOD), limit of quantification (LOQ), and precision, were evaluated. The linearity range ranged from 0.72 to 2.50 ng/L, with corresponding LOD and LOQ values of 0.22 and 0.72 ng/L, respectively. Precision was evaluated by conducting three replicates of the three concentration levels, resulting in %RSD values of 11.8 %, 5.1 %, and 3.9 %, respectively. An enrichment factor (EF) of 112 was achieved. The optimized method was applied for cadmium determination in various matrices, including drinking water, environmental water, seafoods, yielding %recovery in the ranges of 78.05–102.41 %. Finally, comparison of t-values between the developed method and CRMs demonstrated satisfactory results at a 95 % confidence level. [Display omitted] •Natural deep eutectic solvent was used for DLLME-SFOD with vortex-assisted.•Multivariate optimization technique was applied in this method to detect optimum condition.•ETAAS was used for cadmium analysis in water and sea food samples at ng/L level.