Instrument: Shimadzu TOC-V Analyzer
A Shimadzu TOC-V Analyzer measures DOC by high temperature combustion method.
TOC samples were collected in 40 mL precombusted borosilicate vials after these were prerinsed with the sample, followed by acidification to ~pH 2 using 12M trace metal-grade HCl, and capped with acid-washed teflon-lined septa. TOC concentrations were quantified by combusting the unfiltered samples and measuring the CO2 released using a non-dispersive infrared detector. The instrument precision was checked using low carbon deep seawater TOC samples.