Simultaneously speciation of mercury in water, human blood and food samples based on pyrrolic and pyridinic nitrogen doped porous graphene nanostructure.

A rapid and efficient method based on a novel nitrogen-doped porous graphene nanostructure (NDPG) was used for the speciation of mercury in water and human blood samples by the CV-AAS. The mixture of the NDPG, ionic liquid, and acetone was rapidly injected into the human blood, water, and food samples for mercury separation by the cloud point assisted dispersive ionic liquid-micro solid-phase extraction (CPA-DIL-µ-SPE) at pH 7.5. The UV-microwave accessory converted the organic mercury (R-Hg) to inorganic mercury, and total mercury (TM) was determined. Finally, the organic mercury was calculated by subtracting the inorganic and entire mercury contents. By optimizing, the linear range, LOD, and enrichment factor were obtained (0.01-6.80 µg/L; 0.005-3.60 µg/L), (2.6 ng/L; 1.2 ng/L) and (9.8; 20.2) for the mercury species in human blood and water/food samples, respectively (Mean of RSD < 1.9 %). The CRM samples obtained the validation of the procedure.

Simultaneously speciation and determination of manganese (II) and (VII) ions in water, food, and vegetable samples based on immobilization of N-acetylcysteine on multi-walled carbon nanotubes.

A novel method based on the immobilization of N-acetylcysteine on chloro-functionalized multi-walled carbon nanotubes (MWCNTs@NAC) was used for the speciation of manganese ions [Mn (II) and Mn(VII)] in water samples. Also, the total manganese (TMn) in vegetables and food samples was determined by the AT-FAAS. By ultrasound-assisted-dispersive ionic liquid trap micro solid-phase extraction (UA-DILT-µ-SPE), the Mn (II)/Mn(VII) ions were extracted in the presence of MWCNTs@NAC for 50 mL of water samples at a pH of 6.5 and 3.0, respectively. The adsorption capacity of MWCNTs@NAC for Mn(II) and Mn(VII) ions was obtained at 146.7 mg g-1 and 138.8 mg g-1, respectively. Under the optimized conditions, the detection limits (LOD), linear range (LR), and enrichment factor (EF) for Mn(II) and Mn(VII) ions were obtained (0.12 µg L-1; 0.14 µg L-1), (0.48-36 µg L-1; 0.55-38.1 µg L-1) and (100.2; 94.5), respectively. The proposed methodology was successfully validated by the CRM samples.