Synthesis and Physical Properties Characterization of Artificial Seawater Samples Ranging from 36,052 ppm (Standard Seawater) to 80,027 ppm
Description
A data repository containing sample preparation protocols, physical property measurements, and elemental composition analysis for artificial seawater solutions. Repository Structure 01_Sample_Preparation/ Documentation and recipes for preparing artificial seawater samples at different Total Dissolved Solids (TDS) concentrations. • exact_salt_composition.csv - Detailed breakdown of salt components and their exact concentrations used in each sample 02_Physical_Properties/ Physical and chemical characterization data for samples across different TDS ranges. • ec_and_pH_by_tds.csv - Electrical conductivity (EC) and pH measurements as a function of TDS • osmolality_data.csv - Osmolality measurements for sample osmotic potential analysis • OsmolalityVsTDS.svg - Osmolality vs TDS plot • pHvsTDS.svg - pH vs TDS plot of the sample prepared • physical_properties_summary_overall.csv - Comprehensive summary of all physical properties across all samples 03_ICP-OES/ Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) elemental analysis results. • B Expected vs. ICP-OES.svg - Comparison of Boron expected and observed ICP-OES • Ca Expected vs. ICP-OES.svg - Comparison of Calcium expected and observed ICP-OES • ICP-OES_by_tds.csv - Elemental composition data organized by TDS concentration • ICP-OES_spikes.csv - ICP-OES spike recovery data for method validation and quality control • K Expected vs. ICP-OES.svg - Comparison of Potassium expected and observed ICP-OES • Mg Expected vs. ICP-OES.svg - Comparison of Magnesium expected and observed ICP-OES • Na Expected vs. ICP-OES.svg - Comparison of Sodium expected and observed ICP-OES • S Expected vs. ICP-OES.svg - Comparison of Sulfur expected and observed ICP-OES • Sr Expected vs. ICP-OES.svg - Comparison of Strontium expected and observed ICP-OES
Files
Steps to reproduce
1. Materials: Analytical balance DI water Two 250 mL round‑bottom flasks, 1 L cylinders, and 1 L media bottles Micropipettes Magnetic stir plates and sterilized stir bars pH meters (Fisherbrand AB150; Hach HQ40d PHC101) EC probe (Hach HQ40d CDC401) Osmometer (VAPRO 5600) ICP‑OES system with autosampler 0.45 µm syringe filters 1% HNO₃ for dilutions 2. Preparation of Stock Solutions Weigh all required salts individually and rinse weighing boats with DI water for quantitative transfer. Add salts and rinsate into two separate 250 mL flasks (Stock 1 and Stock 2). Add ~100 mL DI water and stir until dissolved. Transfer each solution into a cleaned 1 L measuring cylinder. Rinse flasks with 100 mL DI water and add to cylinders. Dilute to 1 L, transfer to 1 L bottles, and mix thoroughly. 4. Preparation of Artificial Seawater Samples Prepare 100 mL samples at each target TDS (36,052–80,027 ppm), with three replicates per salinity. Clean 100 mL bottles (detergent, ethanol, DI water). Weigh NaCl and Na₂SO₄ using the TDS scaling factor; transfer all solids with DI water rinse. Add 20 mL DI water and dissolve salts with stirring. Add measured volumes of Stock 1, then Stock 2, using calibrated micropipettes. Stir ~5 min, transfer to a 100 mL cylinder, rinse, and dilute to 100 mL. Return to bottle and vortex to homogenize. 5. Temperature Equilibration Place samples in a 25 °C water bath. Equilibrate until the internal temperature stabilizes at 25 °C. 6. EC and pH Measurements Calibrate pH probes daily (pH 7.01 and 10.01). Rinse, blot, and immerse probes vertically. Record pH using two meters. Measure EC twice per sample: using existing calibration after custom calibration with 50,000 and 80,000 mg/L standards Record stable values (three identical readings). 7. Osmolality Measurements Calibrate the VAPRO 5600 according to manufacturer instructions. Measure each replicate three times. Record stabilized values. 8. ICP‑OES Sample Preparation Select samples at 36,052–80,027 ppm for ICP‑OES. Filter samples <55,000 ppm through 0.45 µm filters. Dilute sequentially to 500× (10×, 10×, 5×) in 1% HNO₃. Prepare additional 5× and 10× dilutions for B and Sr. 9. ICP‑OES Calibration and Analysis Prepare fresh standards: 1, 10, 100 ppm (Na, Mg, Ca, K, S) 0.1, 1, 10 ppm (Sr, B) Load blanks, standards, and samples in increasing‑TDS order. Insert QC samples at run start and every 10 samples. Select emission lines based on peak stability and RSD. Run samples in axial and radial modes as appropriate. 10. ICP‑OES Spike Recovery Prepare cation spike solutions gravimetrically. Mix spike solutions with seawater at a fixed volume ratio. Dilute identically to unspiked samples and analyze under the same ICP‑OES conditions.
Institutions
- King Abdullah University of Science and TechnologyMecca Region, Jeddah