title: Phosphate solubility and the cyanate-mediated synthesis of pyrophosphate.
abstract: The justification for a less alkaline primordial ocean (than present) is briefly reviewed, along with constraints on aqueous phosphate under such conditions. Based on the assumption that CaHPO(4) dihydrate determined the availability of phosphorus species, we have carried out laboratory simulations to determine equilibrium concentrations as a function of pH (in PIPES buffer) with added NaCl and CaCl(2). Consistent with expectations, solubility declines with higher pH and [CaCl(2)], but increases only slightly with [NaCl]. Significantly, PIPES shows no specific effect on the dissolution beyond its influence on pH and ionic strength. Data are also presented on the synthesis of pyrophosphate from the NaOCN/CaHPO(4).2H(2)O system, which could have provided a source of this phosphate anhydride on the early Earth.
authors.affiliation: New York Center for Studies on the Origins of Life, School of Mathematics and Sciences, The College of St. Rose, 432 Western Avenue, Albany, NY 12203-1490, USA. haganw@strose.edu
authors.forename: William J
authors.initials: WJ
authors.lastname: Hagan
authors.forename: Amanda
authors.initials: A
authors.lastname: Parker
authors.forename: Amy
authors.initials: A
authors.lastname: Steuerwald
authors.forename: Meagan
authors.initials: M
authors.lastname: Hathaway
mesh_terms: D002122:Calcium Chloride / Q000737:chemistry; D002130:Calcium Phosphates / Q000737:chemistry; D002621:Chemistry / Q000379:methods*; D003485:Cyanates / Q000737:chemistry*; D011756:Diphosphates / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000737:chemistry; D008956:Models, Chemical; D010710:Phosphates / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry; D012995:Solubility; D013696:Temperature
chemical_list: D002130:Calcium Phosphates; D003485:Cyanates; D011756:Diphosphates; D010710:Phosphates; D012965:Sodium Chloride; D008274:Magnesium; D002122:Calcium Chloride; C494366:calcium phosphate, dibasic, dihydrate