Instrument: Automatic titrator
Instruments that incrementally add quantified aliquots of a reagent to a sample until the end-point of a chemical reaction is reached.
TA was calculated from linear Gran plots (Gran 1952) after duplicate potentiometric titration (Brewer et al. 1986) using a TitroLine alpha plus (Schott Instruments, Mainz, Germany). Average precision was ± 5 μmol kg-1. Certified Reference Materials (CRMs, Batch No. 54) supplied by A. Dickson (Scripps Institution of Oceanography, USA) was used as a control.