The definition of alkalinity(TA ,i.e. total alkalinity might be helpful. Total alkalinity is not a specific thing but a measure of a number of things:
"....TA is defined as the amount of acid required to lower the pH of the sample to the point where all of the bicarbonate [HCO3-] and carbonate [CO3--] could be converted to carbonic acid [H2CO3]....."
"...TA = [HCO3-] + 2[CO3--] + [B(OH)4-] + [OH-] + [Si(OH)3O-] + [MgOH+] + [HPO4--] + 2[PO4---] - [H+]...."
http://www.advancedaquarist.com/2002/2/chemistry
"....TA is defined as the amount of acid required to lower the pH of the sample to the point where all of the bicarbonate [HCO3-] and carbonate [CO3--] could be converted to carbonic acid [H2CO3]....."
"...TA = [HCO3-] + 2[CO3--] + [B(OH)4-] + [OH-] + [Si(OH)3O-] + [MgOH+] + [HPO4--] + 2[PO4---] - [H+]...."
http://www.advancedaquarist.com/2002/2/chemistry
