The ECWQL requires a TKN hot block that conforms to the requirements in EPA 351.2 and Standard Methods 4500-NorgD. The unit should have all of the below features: • Include both the heading block, controller, sample tube racks and a set of sample tubes, and the manifold. • Electrical: must work with 220 V electrical outlet • Controller should be programmable and allow for user selection of temperatures, ramp rates and times. Digestion protocols must be savable and selectable. • Block must be made with non-corrosive material. • Block must be able to achieve and hold 380C for 30 minutes. • Block must fit 100 mL round bottle tubes for TKN analysis • Block must have 40 or more positions for QC and sample digestions.
