水稻根表胶膜的浸提及其元素测定方法

THE EXTRACTION AND ELEMENTAL ANALYSIS OF IRON PLAQUE FROM THE SURFACE OF RICE ROOTS

选择柠檬酸钠作为络合剂,比较了碳酸氢钠、乙酸钠二种缓冲体系下,盐酸羟胺、抗坏血酸和1/2盐酸羟胺+1/2抗坏血酸组合对水稻根表铁、锰的浸提能力.结果表明,水稻根表铁、锰浸提量与还原剂种类和缓冲体系的pH值有关.在六种浸提剂中,抗坏血酸-柠檬酸钠-乙酸钠(ACA)浸提水稻根表铁、锰的浸提量最大,为57307mg.kg-1和1689mg.kg-1,相当于DCB浸提水稻根表铁、锰浸提量的99%和109%.ICP测定浸提液中铁、锰、磷、硫等的变异系数也低于DCB浸提的同类元素.因此,推荐ACA-ICP作为水稻根胶膜浸提与元素测定方法.

The objective of this paper was to identify a non-sulfur containing extractant to extract iron plaque on the surface of rice roots. Compared the iron plaque extraction efficiency of six treatment combinations consisting of three reducing reagents （hydroxylamine, ascorbic acid, 1/2 hydroxylamine ＋ 1/2 ascorbic acid） and two buffer solution systems （bicarbonate and acetic acid） . Sodium citrate was used as a complexing agent. The elemental content in the extractions was analyzed using inductively coupled plasma （ICP） emission spectroscopy. The results showed that the amounts of Fe and Mn extracted from iron plaque on rice root surfaces were affected by the type of reducing reagent and the buffer pH. The ascorbic-citrate-acetic solution （ACA） had the highest extraction efficiency among the six extraction treatments. Specifically, 57307 mg Fe·kg^-1 were extracted with ACA which was equivalent to 99% of the Fe extracted with DCB. Similarly, 1689 mg Mn·kg^-1 were extracted with ACA, which was 109% of the Mn extracted with DCB. The Fe, Mn, P and S in the ACA solution was simultaneously determined by ICP, and the corresponding coefficient of variations were lower than in DCB extracts. These results indicate that the ACA-ICP combination is an effective method for the extraction and elemental analysis of iron plaque from the root surface of rice.