The total boron (BT) is the sum of boron species in a solution. In the environment these species usually include boric acid and borate, for example:
BT = [H2BO3−] + [H3BO3]
where,
BT is the total boron concentration
[H2BO3−] is the dihydrogen borate concentration
[H3BO3] is the boric acid concentration
Total boron is an important quantity when determining alkalinity due to borate's contribution to a solution's acid neutraling capacity. Total boron is a conservative element in seawater, and can thus be calculated by simply knowing the salinity.
References
Total boron Wikipedia(Text) CC BY-SA