Ascorbic acid as a reducing agent in quantitative analysis

Miniaturized, rapid separation of neodymium from ultramafic and chondritic samples prior to high precision measurements of 142,143Nd/144Nd isotope ratios by TIMS

“…Before separation, ascorbic acid (100 to 600 mg, depending on the concentration of iron in the sample) is added as a reducing agent 13 until a test for Fe (III) with a 1 M aqueous solution of ammonium thiocyanate gives a faint rose colour. Then, the solution is loaded portion-wise (e.g., 5 mL per 5 mL) onto the TRU column, before a final rinse of the PFA jar and the column reservoir with twice 1 mL of fresh 1M HNO 3 .…”

Ascorbic Acid

“…Rao and R a o [ 2 ] observed that the potential changes from -0-012 V (at pH 8-7) up to + 0-326 V (at pH 1-05).…”

“…[2] Solutions of ascorbic acid in glacial acetic acid are less stable than aqueous solutions. The reducing power of glacial acetic acid solu tions decreases daily by about 0-5 per cent.…”

“…il2 * l >* 2] In the titration of iodate with ascorbic acid in hydrochloric acid solution, the end-point is detected by the disappearance of the colour due to elementary iodine formed by reduction or, in the presence of mercury (II) chloride and selenious acid, by the precipitation of calomel. In the latter case, the reduction of iodate to iodide proceeds without intermediate liberation of iodine (the iodide ions are bound in a complex form by HgCl 2 ).…”