Table 1.
Reaction conditions of various reaction samples for the synthesis of various inorganic condensed P compounds.
| Sample | Description |
|---|---|
| P3 | 0.1 g Na2HPO3 5H2O, 7 mL DDI water, 0.5 g urea, pH = 8.5 |
| P3-gyp | 0.1 g Na2HPO3 5H2O, 7 mL DDI water, 0.5 g urea, 0.2 g CaSO4·2H2O, pH = 8.5 |
| P3-MgCl2 | 0.1 g Na2HPO3 5H2O, 7 mL DDI water, 0.5 g urea, 0.2 g MgCl2, pH = 8.5 |
| P3-NaCl | 0.1 g Na2HPO3 5H2O, 7 mL DDI water, 0.5 g urea, 0.2 g NaCl, pH = 8.0 |
| P3-Am.Carb.1 | 0.1 g Na2HPO3 5H2O, 7 mL DDI water, 0.5 g urea, 0.4 g (NH4)2CO3, pH = 8.0 |
| P3-Am.Carb.2 | 0.1 g Na2HPO3 5H2O, 7 mL DDI water, 0.5 g urea, 0.8 g (NH4)2CO3, pH = 8.0 |
| P3-No.Ad. | 0.1 g Na2HPO3 5H2O, 7 mL DDI water, no additive, pH = 7.5 |
| P3-Kao. | 0.1 g Na2HPO3 5H2O, 7 mL DDI water, 0.5 g urea, 0.3 g kaolinite, pH = 8.5 |
| P3-SiO2 | 0.1 g Na2HPO3 5H2O, 7 mL DDI water, 0.5 g urea, 0.25 g white sand, pH = 8.5 |
| P3-IO | 0.1 g Na2HPO3 5H2O, 7 mL DDI water, 0.5 g urea, 0.25 g instant ocean, pH = 8.0 |
| P3-NH4Cl | 0.1 g Na2HPO3 5H2O, 7 mL DDI water, 0.5 g urea, 0.4 g NH4Cl, pH = 8.0 |
| HP3-No.Ad. | 0.1 g H3PO3, 7 mL DDI water, no additive, pH = 2 |
| HP3-U | 0.1 g H3PO3, 7 mL DDI water, 0.5 g urea, pH = 2 |
| P3-NWD | 0.1 g Na2HPO3 5H2O, 7 mL DDI water, 0.5 g urea, pH = 8.5 |
| P1-U | 0.1 g NaH2PO2·H2O, 7 mL DDI water, 0.5 g urea, pH = 6.0, NWD |
| P3-thio. | 0.1 g Na2HPO3 5H2O, 7 mL DDI water, 0.5 g thiourea, pH = 8.5 |
Prebiotic synthesis of condensed-P compounds. Various conditions tried in the study. Each of the samples were heated uncovered at 78–83 °C for 3 days and were given wet–dry cycle treatment for 3 days e.g., every 24 h. Each sample received three wet and three dry cycles. The meanings of the abbreviations used are; P3 (phosphite), gyp (gypsum), Am.Carb.1 (ammonium carbonate), P3-No.Ad. (phosphite with no additive), Kao. (kaolinite), IO (instant ocean), HP3-No.Ad. (phosphorous acid with no additive), HP3-U (phosphorous acid with urea), P3-NWD (phosphite with no wet–dry cycles), P1 (hypophosphite), and thio means (thiourea). Samples P3-NWD and P1-U represent ‘Warm-Pool Model’ Theme suggested in Section 2.2, whereas all the other samples represent ‘wet–dry cycles’ scenario suggested in Section 2.1, respectively.