| 摘要 |
A method for collection of nitrate, namely in view of nitrogen or oxygen isotope ratio measurement, comprises the steps of:
a) passing a nitrate-containing liquid sample, preferably after a pre-treatment step, over an anion exchange material to retain nitrates thereon;
b) eluting nitrates from said anion exchange material with an eluting agent comprising sulphuric acid, phosphoric acid or a mixture of them;
c) neutralizing the nitrate-containing eluate with a neutralizing agent selected from the group consisting of: lead oxide, calcium oxide, barium oxide, strontium oxide, the corresponding hydroxides, or mixtures of two or more of these compounds. |
