Other salts, such as
cupric sulfate and phosphate salts ([Na.sub.2]HP[O.sub.4], K[H.sub.2]P[O.sub.4]), were added as promoters.
A 250/[micro]L portion of each sample was mixed with 1 mL of Biuret reagent (1.5 g/L
cupric sulfate, 6.0 g/L sodium potassium tartrate, and 30.0 g/L sodium hydroxide), mixed by inversion, and allowed to stand for 30 min at room temperature.
Baker and Ammerman (1995) reported that the relative bioavailability estimates of organic Cu sources ranged between 88% and 147% of the response to
cupric sulfate in poultry, swine, sheep, and cattle.
Recently NIST researchers have demonstrated superconformal electrodeposition of copper in 500 nm deep trenches ranging from 500 nm to 90 nm in width using an acid
cupric sulfate electrolyte containing chloride (Cl), polyethylene glycol (PEG), and 3-mercapto-1-propanesulfonate (MPSA).
Peak response of DHA in the solution was compared with that of DHA obtained from a standard solution of ascorbic acid after oxidation in 0.1 mol/L acetate buffer containing 10 mmol/L
cupric sulfate for 1 h at room temperature.