Synthesis and physical properties characterization of artificial seawater samples

This dataset comprises synthesized artificial seawater samples prepared in accordance with ASTM D1141-98 and spanning an extended salinity range from 36,052 to 80,027 ppm. The samples reproduce the major ionic composition of seawater (Na⁺, Ca²⁺, Mg²⁺, K⁺, Sr²⁺, Cl⁻, Br⁻, F⁻, HCO₃⁻, CO₃²⁻, SO₄²⁻, and B(OH)₄⁻), with constant inter‑ionic molar ratios maintained above standard seawater salinity through a total dissolved solids (TDS) scaling approach. Carbonate and borate species were handled separately because their aqueous speciation is pH‑dependent. For each synthesized solution, experimentally measured physical properties are reported, including density (36,052-46,000 ppm), electrical conductivity, pH, and osmolality, from which osmotic pressure may be derived. Measurements are provided together with detailed preparation metadata, including stock solution volumes, scaling factors, and dilution procedures, allowing absolute salinity (SA) to be explicitly defined for every sample and directly linked to the measured properties. To validate the synthesized ionic composition, inductively coupled plasma optical emission spectroscopy (ICP‑OES) measurements of Na, Mg, Ca, K, Sr, S, and B were performed at selected salinities spanning the full range (36,052-80,027 ppm). Comprehensive documentation of sample preparation, analytical protocols, and measurement conditions is included to ensure reproducibility. The dataset enables derivation of empirical relationships between absolute salinity (or TDS) and key thermophysical properties, supports evaluation of seawater property models extrapolated to elevated salinities, and provides high‑quality reference data for laboratory calibration. Potential applications include desalination process modeling, sensor development, instrument validation, and assessment or extension of thermodynamic and empirical seawater property frameworks under high‑salinity conditions relevant to brines and engineered seawater systems.