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Background and objective: Table salt is an ideal vehicle for the delivery of micronutrients. This study assessed the quality of refined salts and locally processed salts in Awe and Keana local government areas, Nasarawa state, Nigeria. Materials and methods: Forty-five samples were collected from local markets in Nasarawa state. Moisture content, water-insoluble matter, and acid-insoluble matter were determined according to the AOAC method. Sodium chloride and iodine contents were determined by titration. The concentration of calcium, potassium, magnesium, and sodium was determined by inductively coupled plasma-mass spectrometry (ICP-MS). Results and conclusion: Moisture content of the refined and unrefined salts ranged from 0.060 to 0.133% and 0.599 to 2.574%, respectively. The moisture content and amounts of water-insoluble and acid-insoluble matters in the unrefined salts were higher than the refined salts. The concentration of sodium chloride in most of the unrefined salts did not meet the national minimum limit of 97%. The concentration of iodine, calcium, potassium, and magnesium in the refined salts was significantly higher than the unrefined samples. Iodine content in the refined and unrefined salts ranged from 22.22 to 40.20 mg/kg and below the detection limit of 6.35 mg/kg, respectively. None of the unrefined salts met the minimum iodine content of 30 mg/kg. We concluded that the locally processed salts available in Awe and Keana local markets were highly deficient in essential elements and were of poor quality for use as table salt. [ABSTRACT FROM AUTHOR]

Four new metal-aluminum layered double hydroxides (LDHs), Mg-Al(OH)2PO4 (1), Mg-Al(OH)2PO4PF6 (2), Ca-Al(OH)2SO4 (3), and Ca-Al(OH)2PO4PF6 (4), were prepared by the coprecipitation method followed by mild hydrothermal processing at 60°C. Mg2+ and Ca2+ in solution with Al3+ were titrated with NaOH over 3–5 h to yield Mg-Al and Ca-Al layered double hydroxides, respectively, incorporating PO43−, PO43−PF6−, and SO42− anions in the interlamellar spaces. The isolated compounds were characterized with the help of XRD, IR, and SEM/EDAX, and their ability to remove scale-forming ions from the aqueous system was studied with the help of atomic absorption spectroscopy (AAS). The SEM micrographs of Mg-O-Al-OH and Ca-O-Al-OH layers intercalated with PO43− and/or [PO4PF6]4− anions are similar consisting of uniform nanospheres with an average size of 100 nm, while the M-O-Al-OH layer of compound 3, intercalated with SO42− anions, consists of hexagonal nanoplate crystals. In the infrared spectra, the characteristic absorption band for water molecules was observed in all the compounds. The XRD pattern showed that d012 and d104 peaks of M-Al-PO4 LDHs corresponding to interplanar spacing of 3.4804 and 2.5504 Å, respectively, shifted to higher 2θ values for the M-Al-PO4PF6 system, which indicates a decrease in the interlamellar spacing as PF6− was incorporated along with PO43− anion. The XRD pattern for Ca-Al-SO4 LDHs was quite different, showing the presence of low-angle peaks at 2θ = 11.68 and 14.72°. The results of the column adsorption studies showed that there was a significant removal of Ca2+ by all the compounds under investigation with an efficiency of 84–99%. However, compounds 1 and 2 remove Fe2+ effectively with the efficiency of 98.73 and 99.77%, respectively; compounds 3 and 4 were shown to have little or no effect. [ABSTRACT FROM AUTHOR]